Article

Cervical laminectomy and instrumented lateral mass fusion: techniques, pearls and pitfalls

May 2013
European Spine Journal 24(S2)

DOI:10.1007/s00586-013-2838-x

Source
PubMed

Authors:

Michael Mayer

Paracelsus Medical University

Alexander Auffarth

Paracelsus Medical University

Heiko Koller

Introduction Cervical laminectomy is a reliable tool for posterior decompression in various cervical spine pathologies. Although there is increasing evidence of superior clinical, neurological and radiological outcomes when using anterior cervical decompression, laminectomy can be a valuable tool when combined with instrumented lateral mass fusion for carefully selected indications. Methods Literature review. Results This review article will provide decision-making guidance, technical advices and pitfalls. The technical advice for laminectomy and instrumented lateral mass fusion is illustrated. The authors review the literature on outcomes and complications and suggest indications for the safe and successful application of cervical laminectomy and lateral mass fusion.

Rod migration to the occiput after C3-7 instrumentation: A rare case report and literature review

Article

Full-text available

Oct 2024

Introduction and importance Cervical canal stenosis often requires posterior laminectomy with lateral mass (LM) screw/rod fixation for sagittal stability. Although rare, rod migration can pose serious risks, such as penetration into cranial structures, emphasizing the need for vigilant postoperative monitoring and prompt intervention. Case presentation A 65-year-old male with no significant prior medical history underwent C3–7 laminectomy with LM screw/rod fixation for cervical canal stenosis. Two months postoperatively, the patient experienced persistent neck pain. Imaging revealed right-sided rod migration into the occipital bone, confirmed by CT scan. Urgent revision surgery was performed to remove the migrated rod, resulting in a successful recovery without further complications during follow-up evaluations. Clinical discussion Rod migration is a rare but serious complication of LM screw/rod fixation, influenced by technical factors such as screw placement, angulation, and rod length. Accurate preoperative planning, meticulous surgical technique, and detailed postoperative surveillance are crucial in preventing such occurrences. This case highlights the significance of recognizing potential hardware complications early, facilitated by imaging modalities like CT, to avoid severe neurological outcomes. Conclusion This case underscores the necessity of thorough preoperative assessment, precise surgical execution, and rigorous postoperative monitoring in managing cervical spine stabilization surgeries. Improved diagnostic imaging and prompt surgical intervention are key to mitigating risks associated with rod migration, ultimately enhancing patient outcomes.

A Rare Case of Occupational Aniline Poisoning: Management in a Limited-Facility Setting

Article

Full-text available

Sep 2024

Introduction Cyanosis along with altered mental should bring all the possible ethiologies into her mind in a minimum of time, based on the trauma, medical, environmental, and occupational history of the patient. Poisoning with methemoglobinemia inducing agents is one of the most important differentials especially when a history of occupational exposure to these agents is present. Case Report The patient, a 41-year-old healthy woman and engineer, experienced symptoms after exposure to aniline leading to dizziness and weakness, prompting a visit to the emergency department with cyanosis and low oxygen saturation. Initial vital signs showed decreased oxygen levels and elevated respiratory rate with normal ABG values despite ongoing cyanosis. Patient required intubation, mechanical ventilation, and was diagnosed with ARDS based on chest X-ray findings. Management included IV diuretics, 100% oxygen, and antioxidant treatment in the ICU. Despite treatment, oxygen saturation remained at 88% on the first day. Conclusion This case is a reminder of the importance of taking occupational history and management of aniline toxicity in a setting where methylene blue, the drug of choice for aniline toxicity, is not available in the drug stock.

Biomechanical analysis of laminectomy, laminoplasty, posterior decompression with instrumented fusion, and anterior decompression with fusion for the kyphotic cervical spine

Article

Full-text available

Jun 2022

Purpose: Anterior and posterior decompressions for cervical myelopathy and radiculopathy may lead to clinical improvements. However, patients with kyphotic cervical alignment have sometimes shown poor clinical outcomes with posterior decompression. There is a lack on report of mechanical analysis of the decompression procedures for kyphotic cervical alignment. Methods: This study employed a three-dimensional finite element (FE) model of the cervical spine (C2-C7) with the pre-operative kyphotic alignment (Pre-OK) model and compared the biomechanical parameters (range of motion (ROM), annular stresses, nucleus stresses, and facet contact forces) for four decompression procedures at two levels (C3-C5); laminectomy (LN), laminoplasty (LP), posterior decompression with fusion (PDF), and anterior decompression with fusion (ADF). Pure moment with compressive follower load was applied to these models. Results: PDF and ADF models' global ROM were 40% at C2-C7 less than the Pre-OK, LN, and LP models. The annular and nucleus stresses decreased more than 10% at the surgery levels for ADF, and PDF, compared to the Pre-OK, LN, and LP models. However, the annular stresses at the adjacent cranial level (C2-C3) of ADF were 20% higher. The nucleus stresses of the caudal adjacent level (C5-C6) of PDF were 20% higher, compared to other models. The PDF and ADF models showed a less than 70% decrease in the facet forces at the surgery levels, compared to the Pre-OK, LN, and LP models. Conclusion: The study concluded that posterior decompression, such as LN or LP, increases ROM, disc stress, and facet force and thus can lead to instability. Although there is the risk of adjacent segment disease (ASD), PDF and ADF can stabilize the cervical spine even for kyphotic alignments.

Perioperative Complications of Surgery for Degenerative Cervical Myelopathy: A Comparison Between 3 Procedures

Article

Full-text available

Mar 2021

Study Design Retrospective comparative study. Objectives To compare the perioperative complications of propensity score-matched cohorts of patients with degenerative cervical myelopathy (DCM), who were treated with anterior cervical discectomy and fusion (ACDF), posterior laminectomy with fusion, or laminoplasty. Methods The Humana PearlDiver Patient Record Database was queried using the International Classification of Diseases (ICD-9 and ICD-10) and the Current Procedural Terminology (CPT) codes. Propensity score-matched analysis was done using multiple Chi-squared tests with Bonferroni correction of the significance level. Results Cohorts of 11,790 patients who had ACDF, 2,257 patients who had posterior laminectomy with fusion, and 477 patients who had laminoplasty, were identified. After propensity score matching, all the 3 groups included 464 patients. The incidence of dysphagia increased significantly following ACDF compared to laminoplasty, P < 0.001, and in laminectomy with fusion compared to laminoplasty, P < 0.001. The incidence of new-onset cervicalgia was higher in ACDF compared to laminoplasty, P = 0.005, and in laminectomy with fusion compared to laminoplasty, P = 0.004. The incidence of limb paralysis increased significantly in laminectomy with fusion compared to ACDF, P = 0.002. The revision rate at 1 year increased significantly in laminectomy with fusion compared to laminoplasty, P < 0.001, and in ACDF compared to laminoplasty, P < 0.001. Conclusions The incidence of dysphagia following laminectomy with fusion was not different compared to ACDF. Postoperative new-onset cervicalgia and revisions were least common in laminoplasty. The highest rate of postoperative limb paralysis was noticed in laminectomy with fusion.

Intraoperative evoked potentials in patients with ossification of posterior longitudinal ligament

Article

Full-text available

Feb 2022
J Clin Monit Comput

Preoperative somatosensory evoked potentials (preSEPs) are used to evaluate the severity of myelopathy, and intraoperative neurophysiological monitoring (IONM) is used to reduce iatrogenic damage during operations. However, the correlation between preSEPs and IONM on postoperative neurologic deterioration (PND) in ossification of the posterior longitudinal ligament (OPLL) has not been studied. Thus, under the hypothesis that the patients with deteriorated preSEPs would be more likely to have significant changes in intraoperative SEPs (ioSEPs), and that this would be correlated with PND, we investigated the prognostic value of preSEPs on IONM and PND. This retrospective study included 265 patients who underwent preSEPs and IONM between January 2015 and July 2019. Muscle strength, the sensory scale of the Japanese Orthopaedic Association score examined within 3 days preoperatively, and at 48 h and 4 weeks postoperatively, was analysed. PreSEPs and intraoperative SEPs (ioSEPs) were recorded by stimulating the median and tibial nerves. Intraoperative motor evoked potentials (ioMEPs) were elicited by transcranial electrical stimulation over the motor cortex. PreSEPs latency prolongation of the median and tibial nerves showed significant correlations with ioSEPs. PMD at 48 h or 4 weeks after surgery correlated with ioSEPs and ioMEPs amplitudes. Postoperative sensory deterioration (PSD) at 48 h or 4 weeks after surgery correlated with latency prolongation of ioSEPs. There was a positive correlation between amount of blood loss and maximum percentage of ioSEPs latency prolongation and a negative correlation with PMD at 48 h and 4 weeks postoperatively. PreSEPs predict significant changes in ioSEPs. Furthermore, bleeding control is important to reduce PMD in OPLL.

Clinical efficacy of laminectomy with instrumented fixation in treatment of adjacent segmental disease following ACCF surgery: a retrospective observational study of 48 patients

Article

Full-text available

Apr 2019

This study was designed to investigate the clinical efficacy of laminectomy with instrumented fixation in treatment of adjacent segmental diseases following anterior cervical corpectomy and fusion (ACCF) surgery. Between January 2008 and December 2015, 48 patients who underwent laminectomy with instrumented fixation to treat adjacent segmental diseases following ACCF surgery, were enrolled into this study. The patients were followed up at least 2 years. Pain assessment was determined by visual analogue scale (VAS) score and Neck Disability Index (NDI) score; neurological impairment was evaluated by Japanese Orthopaedic Association (JOA) score; and radiographic parameters were also compared. All comparisons were determined by paired t test with appropriate Bonferronni correction. VAS score preoperatively and at last follow-up was 5.28 ± 2.35 vs 1.90 ± 1.06 (P < 0.001). JOA score preoperatively and at last follow-up was 8.2 ± 3.6 vs 14.5 ± 1.1 (P < 0.001). NDI score preoperatively and at last follow-up was 30.5 ± 12.2 vs 10.6 ± 5.8 (P < 0.001). Moreover, the losses of cervical lordosis and C2-C7 range of motion after laminectomy were significant (both P < 0.005), but not sagittal vertical axis distance. Postoperative complications were few or mild. In conclusion, clinical effectiveness and safety can be guaranteed when the patients undergo laminectomy with instrumented fixation to treat adjacent segmental diseases following ACCF surgery.

Risk factors associated with clinical adjacent segment pathology following multi-level cervical fusion surgery

Article

Full-text available

Nov 2018

Few clinical studies investigate risk factors associated with clinical adjacent segment pathology (CASP) following multi-level cervical fusion surgery. The aim is to record the incidence of postoperative CASP in patients after at least 2 years′ follow-up and to identify possible risk factors that may be associated with the CASP after multi-level cervical surgery. We retrospectively reviewed patients who underwent multi-level cervical surgery in our hospital from January 2004 to February 2016. All patients underwent more than 2 years′ follow-up. The diagnosis of CASP is according to clinical symptoms as well as image findings. Potential risk factors were collected from demographic data and radiographic images. A total of 301 patients after multi-level cervical surgery were analyzed. During follow-up, 28 patients (9.3%) were diagnosed as having CASP. Among these patients, 7 showed symptoms of CASP within 3 years after surgery, 6 showed symptoms between 3 and 5 years, 14 showed symptoms between 5 and 10 years, and the last one showed symptoms more than 10 years later. In the multivariate analysis, degeneration of adjacent segment (OR, 1.592; 95% CI, 1.113–2.277), decreased Cobb angle in fused vertebrae (OR, 2.113; 95% CI, 1.338–3.334) and decreased Cobb angle in cervical spine (OR, 1.896; 95% CI, 1.246–2.886) were correlated with the incidence of CASP during follow-up. The incidence of CASP following multi-level cervical surgery was 9.3% with a mean of about 70 months′ follow-up. Patients with preoperative degeneration of adjacent segment and postoperative imbalance of sagittal alignment have a higher risk of developing CASP after multi-level cervical surgery.

Anterior versus posterior approach to treat cervical spondylotic myelopathy, clinical and radiological results with long period of follow-up

Article

Full-text available

Feb 2018

Background: Cervical spondylotic myelopathy increases with age, but not all cases are symptomatic. It is usually diagnosed clinically and radiologically (X-ray and magnetic resonance imaging). Surgical treatment is indicated in severe symptomatic cases, while treatment controversy exists in the presence of less severe cases. Anterior and posterior approaches are generally used for decompression with no significant differences in the results of both. Methods: A total of 287 patients of cervical spondylotic myelopathy were treated at our hospital between January 2004 and December 2015. Only 140 patients were eligible for our study. They had at least 5 years of follow-up using full clinical scores and radiological evaluation. They were divided into two groups: group I with 73 patients (aged 23-79 years) underwent posterior decompression, lateral mass instrumentation, and fusion, while group II with 67 patients (aged 33-70 years) underwent anterior decompression, instrumentation, and fusion. Neck Disability Index, local score, and X-ray were used in the evaluation of the patients. Results: Preoperative mean ± standard deviation of Neck Disability Index of both the groups was 32.06 ± 6.33 and 29.88 ± 5.48, which improved in the last visit (>5 years) to 5.81 ± 7.39 and 2.94 ± 5.48 for groups I and II, respectively (p value <0.05). The local score of groups I and II was (P = 1, F = 21, G = 31, E = 19) and (P = 1, F = 12, G = 36, E = 18), which on discharge day improved to (P = 1, F = 4, G = 12, E = 55) and (P = 0, F = 3, G = 6, E = 58) at last follow-up, respectively. Fusion rate was nearly equal for both the groups during all the follow-up intervals and it was 91.1% and 91.7% in the last follow-up. Conclusion: There were no significant differences in the clinical and radiological results between the anterior and posterior approaches used in the surgical treatment of spondylotic cervical myelopathy. However, statistically significant results of Neck Disability Index of anterior approach were not clinically important and may be due to changes in the size and shape of the neck in group II.

Anterior versus posterior approach to treat cervical spondylotic myelopathy, clinical and radiological results with long period of follow-up

Article

Full-text available

Apr 2018

Surgical treatment of multilevel cervical spondylosis in patients with or without a history of syringomyelia

Article

Full-text available

Apr 2017
EUR SPINE J

Jörg Klekamp

Purpose: Cervical spondylotic myelopathy (CSM) is the commonest spinal cord disease in adults. This paper compares patients who developed CSM after successful treatment of syringomyelia to those with CSM exclusively related to degenerative spinal disease. Methods: In this prospective study, 70 consecutive patients with CSM and spondylotic changes in at least three levels underwent 73 operations between 2005 and 2015 (mean follow-up: 39 ± 36 months). Patients with treated syringomyelia (group A, n = 30) and those without (group B, n = 40) were distinguished. Japanese Orthopaedic Association (JOA) and European Myelopathy scores (EMS), Karnofksy scores, and scores for individual symptoms were compared. Long-term outcomes were analyzed with progression-free survival rates. Results: Patients of group A were significantly younger with a significantly longer history and lower functional scores compared to group B. 59 laminectomies C3-C6 plus lateral mass fixations, six ventral decompressions with fusion, and eight combined approaches were performed. In both groups, mean JOA (A 9.5 ± 4.3-10.0 ± 4.7; B 11.3 ± 3.7-12.3 ± 4.3), EMS (A 11.4 ± 2.9-12.0 ± 3.1; B 12.2 ± 3.1-13.5 ± 3.3), and Karnofsky scores (A 59 ± 18-62 ± 18; B 68 ± 13-72 ± 15) increased in the first postoperative year with lower scores in group A throughout. Rates for progression-free survival for 5 years were similar in both groups (A 64.2%, B 65.6%). Conclusion: Patients with CSM benefit from decompressive surgery. Surgery should be advocated early for all symptomatic patients with a history of syringomyelia. These patients are at risk for diagnostic delay and worse postoperative results.

Pars interarticularis screws for posterior cervical fusion – investigating a new trajectory using a CT-based multiplanar reconstruction: Part I

Article

Full-text available

Jul 2024
ACTA NEUROCHIR

Background Lateral mass screw fixation is the standard for posterior cervical fusion between C3 and C6. Traditional trajectories stabilize but carry risks, including nerve root and vertebral artery injuries. Minimally invasive spine surgery (MISS) is gaining popularity, but trajectories present anatomical challenges. Research Question. This study proposes a novel pars interarticularis screw trajectory to address these issues and enhance in-line instrumentation with cervical pedicle screws. Materials and Methods A retrospective analysis of reformatted cervical CT scans included 10 patients. Measurements of the pars interarticularis morphology were performed on 80 segments (C3-C6). Two pars interarticularis screw trajectories were evaluated: Trajectory A (upper outer quadrant entry, horizontal trajectory) and Trajectory B (lower outer quadrant entry, cranially pointed trajectory). These were compared to standard lateral mass and cervical pedicle screw trajectories, assessing screw lengths, angles, and potential risks to the spinal canal and transverse foramen. Results Trajectory B showed significantly longer pars lengths (15.69 ± 0.65 mm) compared to Trajectory A (12.51 ± 0.24 mm; p < 0.01). Lateral mass screw lengths were comparable to pars interarticularis screw lengths using Trajectory B. Both trajectories provided safe angular ranges, minimizing the risk to delicate structures. Discussion and Conclusion. Pars interarticularis screws offer a viable alternative to lateral mass screws for posterior cervical fusion, especially in MISS contexts. Trajectory B, in particular, presents a feasible and safe alternative, reducing the risk of vertebral artery and spinal cord injury. Preoperative assessment and intraoperative technologies are essential for successful implementation. Biomechanical validation is needed before clinical application.

Reoperation and Perioperative Complications After Surgical Treatment of Cervical Radiculopathy: A Comparison Between Three Procedures

Article

Oct 2022
SPINE

Study design: A retrospective database study. Objective: The purpose of our study was to compare the perioperative complications and reoperation rates after ACDF, CDA, and PCF in patients treated for cervical radiculopathy. Summary of background data: Cervical radiculopathy results from compression or irritation of nerve roots in the cervical spine. While most cervical radiculopathy is treated nonoperatively, anterior cervical discectomy and fusion (ACDF), cervical disc arthroplasty (CDA), and posterior cervical foraminotomy (PCF) are the techniques most commonly used if operative intervention is indicated. There is limited research evaluating the perioperative complications of these surgical techniques. Methods: A retrospective review was performed using the PearlDiver Patient Record Database to identify cases of cervical radiculopathy that underwent ACDF, CDA, or PCF at 1 or 2 levels from 2007 to 2016. Perioperative complications and reoperations following each of the procedures were assessed. Results: During the study period, 25,051 patients underwent ACDF, 522 underwent CDA, and 3,986 underwent PCF. After propensity score matching, each of the three groups consisted of 507 patients. Surgical site infection rates were highest after PCF (2.17%) compared with ACDF (0.20%) and CDA (0.59%) at 30-days and 3-months, P=0.003, P<0.001 respectively. New onset cervicalgia was highest following ACDF (34.32%) and lowest after PCF (22.88%) at 3- and 6-months, P<0.001 and P=0.003, respectively. Revision surgeries were highest among those who underwent CDA (6.90%) versus ACDF (3.16%) and PCF (3.55%) at 6-months, P=0.007. Limb paralysis was significantly higher after PCF compared to CDA and ACDF at 6-months, P<0.017. Conclusion: The rate of surgical site infection was higher in PCF compared to ACDF and CDA. New-onset cervicalgia was higher after ACDF compared to PCF and CDA at short term follow up. Revision surgeries were highest among those undergoing CDA and lowest in those undergoing ACDF. Level of evidence: 3.

Effect of posterior decompression with and without fixation on a kyphotic cervical spine with ossification of the posterior longitudinal ligament

Article

Oct 2022

Study design: Biomechanical study. Objective: Cervical ossification of the posterior longitudinal ligament (C-OPLL) causes myelopathy. Though posterior decompression for C-OPLL showed positive results, poor outcomes were seen in patients with a kyphotic alignment. Posterior decompression with fusion (PDF) tends to show better results compared to posterior decompression. The aim of this study is to evaluate the effects of the posterior procedures for C-OPLL. Setting: Yamaguchi University. Methods: Based on 3D finite element C2-C7 spine created from medical images and a spinal cord, the following compression models were created: the intact model, K-line 0 mm model, and K-line 2 mm model. These models were used to analyze the effects of posterior decompression with varied lengths of fixation. The stress of the spinal cord was calculated for intact, K-line 0 mm, and K-line 2 mm as preoperative models, and laminectomy (LN)-K-line 0 mm, PDF (C4-C5)-K-line 0 mm, PDF (C3-C6)-K-line 0 mm, LN-K-line 2 mm, PDF (C4-C5)-K-line 2 mm, and PDF (C3-C6)-K-line 2 mm model as operative models in a neutral, flexion, and extension. Results: As the compression increased, stress on the spinal cord increased compared to the intact model. In the neutral, posterior decompression decreased the stress of the spinal cord. However, in flexion and extension, the stress on the spinal cord for LN-K-line 0 or 2 mm, PDF (C4-C5)-K-line 0 or 2 mm, and PDF (C3-C6)-K-line 0 or 2 mm models decreased by more than 40%, 43%, and 70% respectively compared to the K-line 0 or 2 mm model. Conclusions: In kyphotic C-OPLL, it is essential to control intervertebral mobility in the posterior approach.

Surgical Strategy to Protect the Exposed Spinal Cord From Extrinsic Compression in Severe Kyphosis: A Case Report

Article

Feb 2021

The Michel Benoist and Robert Mulholland yearly European spine journal review: a survey of the “surgical and research” articles in the European spine journal, 2015

Article

Full-text available

Jan 2016
EUR SPINE J

Robert C Mulholland

Biomechanical characterization of vertebral body replacement in situ: Effects of different fixation strategies

Article

Sep 2020

Background and objective: Artificial vertebral implant with a lateral or posterior screw-rod fixation system are usually employed in lumbar reconstruction surgery to rebuild the lumbar spine after partial resection due to a tumor or trauma. However, few studies have investigated the effect of the various fixation systems on the biomechanics of the reconstructed lumbar system. This study aims to evaluate the influence of different surgical fixation strategies on the biomechanical performance of a reconstructed lumbar spine system in terms of the strength and long-term stability. Methods: Two typical lumbar spine reconstruction case models that correspond to lateral or posterior fixation systems were built based on the clinical data. Finite element analyses were performed, and comparisons were made between the two models based on the predicted stress distribution of the reconstructed lumbar spine model, bone-growth area of the endplate, and the range of motion under various normal daily activities. Results: The load from the upper vertebral body was found to be effectively transmitted onto the lower vertebral body by a vertebral implant with the lateral fixation system; this was favorable for bone growth after surgery. However, significantly high stresses were concentrated around the interaction region between the screws and bone, owing to the uneven lateral fixation structure; this may increase the risk of bone fractures and screw loosening in the long term. For the posterior fixation case, stably posterior fixation structure was favorable to maintain stability for the reconstructed lumbar spine. However, the load was mainly transmitted via the fixation rod rather than the vertebral implant, owing to the stress shielding effect. Therefore, the predicted strain on the endplate were insufficient for bone ingrowth under most of the spinal activates, which could cause bone loss and prosthesis loosening. Conclusions: In this study, the comparisons of the reconstructed lumbar spine system with lateral and posterior fixation strategies were conducted. The Pros and Cons of these two fixation strategies was deeply discussed and the associated clinical issues were provided. The results of this study will have a clear impact in understanding the biomechanics of the lumbar spine with different fixation strategies and providing necessary instructions to the design and application of the lumbar spinal fixation system.

Clinical comparison between simple laminectomy and laminectomy plus posterior instrumentation in surgical treatment of cervical myelopathy

Article

Full-text available

Jul 2019
EUR J ORTHOP SURG TR

Background Posterior stabilization in patients treated with laminectomy for spondylotic cervical myelopathy is still a debate. Despite both being reported in literature by several authors, some controversies still exist. The aim of this study is to compare clinical and radiological outcomes in patients treated with laminectomy or laminectomy with posterior stabilization. Material and methods We retrospectively evaluated 42 patients affected by cervical myelopathy (mean age 70.43 ± 5.03 years), 19 treated with laminectomy (group A) and 23 with laminectomy and posterior instrumentation (group B). Neurological status was assessed with Nurick scale, pain with VAS and radiological parameters with C2–C7 SVA, T1 slope and C2–C7 lordosis, clinical function with modified Japanese Orthopaedic Association score (JOA). Also, surgery time and blood loss were recorded. Student’s t test was used for continuous variables, while Kruskal–Wallis test was used for categorical values. Results No differences were found in postoperative Nurick scale (p = 0.587), VAS (p = 0.62), mJOA (p = 0.197) and T1 slope (p = 0.559), while laminectomy with fusion showed better postoperative cervical lordosis (p = 0.007) and C2–C7 SVA (p < 0.00001), but higher blood loss (p < 0.00001) and surgical time (p < 0.00001). Both groups showed better Nurick scale (p = 0.00017 for group A and p = 0.00081 for group B), VAS (p = 0.02 for group A and p = 0.046 for group B) and mJOA (p < 0.00001 for both groups) than preoperative values. Conclusions Both treatments are a valuable choice, offering some benefits and disadvantages against each other. Each procedure must be carefully evaluated on the basis of patients’ general status, preoperative pain, signs of instability and potential benefits from cervical alignment correction.

Spinal Meningiomas: A Review

Article

Jan 2014

Meningiomas of the spinal axis have been identified from C1 to as distal as the sacrum. Their clinical presentation varies greatly based on their location. Meningiomas situated in the atlanto-axial region may present similarly to some meningiomas of the craniocervical junction, while some of the more distal spinal axis meningiomas are discovered as a result of chronic back pain. Surgical resection remains the mainstay of treatment, although advancements in radiosurgery have led to increased utilization as a primary or adjuvant therapy. Angiography also plays a critical role in surgical planning and may be utilized for preoperative embolization of hypervascular meningiomas.

Effect of Laminectomy Methods on the Surgical Safety of Automatic Laminectomy Robot

Article

Jan 2025
INT J MED ROBOT COMP

Background The efficacy of laminectomy procedures is contingent on the method of resection. The objective of this study was to investigate the impact of different methods of resection on the surgical safety of automated laminectomy robots, an area that remains uncharted. Methods Lamina resection surgeries using both drilling and layer‐by‐layer methods, are performed on ovine spinal samples. An analysis of the force and lateral deviation at the end of the robotic arm is conducted. Results For the drilling and layer‐by‐layer lamina resection methods, the average peak force for the drilling method is 1.21 N, and deviations are within 1 mm. For the layer‐by‐layer resection method, the peak force reaches 2.39 N, and deviations are within 1.6 mm. Conclusion During the drilling resection, the ultrasonic osteotome experiences less force and minimal lateral deviation. This method demonstrates higher precision and safety in laminar resection surgeries. The drilling method should be the primary choice for robot manufacturers.

Minimally Invasive Instrumentation of the Cervical Spine: Past, Present, and Future

Chapter

Dec 2023
Acta Neurochir

Posterior cervical instrumentation and fusion procedures are becoming more and more common with the aging population and rising numbers of multisegmental and revision procedures. The instrumentation of the cervical spine has so far been performed almost exclusively via open approaches. Over the past two decades, minimally invasive surgery (MIS) techniques have gained increasing popularity. To date, only a few attempts to instrument the cervical spine in a minimally invasive fashion have been reported. The following article, after a detailed review of the currently available literature, overviews MIS in dorsal cervical instrumentation and past, present and future techniques, and it discusses the current limitations. Nevertheless, and because of the multiple advantages of MIS instrumentation, a lot of work remains to be carried out to fully establish MIS procedures for posterior cervical instrumentation.

Accuracy Evaluation of a Novel Spinal Robotic System for Autonomous Laminectomy in Thoracic and Lumbar Vertebrae: A Cadaveric Study

Article

Mar 2023
J BONE JOINT SURG AM

Background: The main function of robots in spine surgery is to assist with pedicle screw placement. Laminectomy, which is as important as pedicle screw placement, lacks a mature robot-assisted system. The aims of this study were to introduce the first autonomous laminectomy robot, to explore the feasibility of autonomous robotic laminectomy, and to validate its accuracy using a cadaveric model. Methods: Forty vertebrae from 4 cadavers were included in the study; 7 thoracic and 3 lumbar vertebrae were randomly selected in each cadaver. The surgeon was able to plan the laminectomy path based on computed tomographic (CT) data before the surgical procedure. The robot performed the laminectomy autonomously, and a postoperative CT scan was made. The deviation of each cutting plane from the plan was quantitatively analyzed, and the accuracy and safety were qualitatively evaluated. The time required for the laminectomy was also recorded. Results: Cuts were performed in 80 laminectomy planes (56 for thoracic vertebrae and 24 for lumbar vertebrae). The mean time for 1-sided laminectomy was 333.59 ± 116.49 seconds, which was shorter for thoracic vertebrae (284.41 ± 66.04 seconds) than lumbar vertebrae (448.33 ± 128.65 seconds) (p < 0.001). The mean time for single-level total laminectomy was 814.05 ± 302.23 seconds, which was also shorter for thoracic vertebrae (690.46 ± 165.74 seconds) than lumbar vertebrae (1,102.42 ± 356.13 seconds) (p = 0.002). The mean deviation of the cutting plane from the plan was 0.67 ± 0.30 mm for the most superior cutting point and 0.73 ± 0.31 mm for the most inferior point. There were no significant differences in the deviation between thoracic vertebrae (0.66 ± 0.26 mm) and lumbar vertebrae (0.67 ± 0.38 mm) at the superior cutting point (p = 0.908) and between thoracic vertebrae (0.72 ± 0.30 mm) and lumbar vertebrae (0.73 ± 0.33 mm) at the inferior cutting point (p = 0.923). In the qualitative analysis of the accuracy of the 80 laminectomy planes, 66 (83%) were classified as grade A, 14 (18%) were grade B, and none was grade C. In the safety analysis, 65 planes (81%) were considered safe and the safety of the other 15 planes (19%) was considered uncertain. Conclusions: The results confirmed the accuracy of this robotic system, supporting its use for laminectomy of thoracolumbar vertebrae. Level of evidence: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Comparison of the Clinical Efficacy of Two Reduction Methods for the Treatment of Irreducible Unilateral Subaxial Cervical Facet Joint Dislocation

Article

Oct 2022

Objective: To compare the clinical efficacy of the minimally invasive technique and the open method in the treatment of irreducible unilateral subaxial cervical facet joint dislocation (SCFD). Methods: From March 2015 to September 2018, 62 patients with unilateral SCFD were studied. The cases were divided into two groups based on different surgery strategies. Thirty-one patients were enrolled in the minimally invasive surgery (MIS) group, and 31 patients were enrolled in the open surgery group (OPEN). The duration of prone position operation, blood loss, and total hospitalization costs were recorded. The clinical effects were evaluated using visual analogue scale (VAS) scores, the Oswestry Disability Index (ODI), and Japanese Orthopedic Association (JOA) scores at each follow-up. In addition, the segmental Cobb's angle (SCA) and intervertebral height (IVH) were recorded and compared. Results: The amount of intraoperative blood loss, prone position operation duration, and total hospital costs in the MIS group were significantly lower than in the OPEN group. The VAS, ODI, and JOA scores of the two groups significantly improved after the operation. A satisfactory fusion rate was obtained in both groups, and the SCA and IVH scores in both groups improved significantly. Conclusion: Minimally invasive reduction had equal clinical efficacy to posterior open surgery. However, MIS was less invasive and had lower costs. Therefore, it is a potential option in the treatment of SCFD.

Quantitative and qualitative analyses of spinal canal encroachment during cervical laminectomy using the kerrison rongeur versus High-Speed burr

Article

Jan 2019

Background: Several cervical laminectomy techniques have been described. One commonly used method involves making bilateral trough laminotomies using either a Kerrison rongeur or a high speed burr, and then removing the lamina en-bloc. Alternatively, some surgeons prefer to thin the lamina with the burr, and then remove the lamina in a piecemeal fashion using Kerrison rongeurs. Some surgeons have warned against the potential risk of iatrogenic spinal cord injury from inserting the Kerrison footplate into a stenotic canal. We aim to quantify the amount of canal encroachment for various methods of cervical laminectomies. Methods: Three attending spine surgeons and two fellows each performed laminectomies using C5 sawbones models. The canal was completely filled with modeling putty to simulate a stenotic spinal cord. Bilateral trough laminotomies were performed using a 1 mm Kerrison, a 2 mm Kerrison, and a 3 mm matchstick high-speed burr. Piecemeal laminectomies were performed with a 2 mm Kerrison. A blinded spine surgery fellow performed all quantitative measurements. Three blinded researchers qualitatively ranked the amount of “canal encroachment”. Results: The average canal encroachment was 0.50 ± 0.45mm for the burr, 1.37 ± 0.68 mm for the 1 mm Kerrison, and 1.47 ± 0.37 mm for the 2 mm Kerrison (p = .002). There was a statistically significant difference between the burr and 1 mm Kerrison (p = .01) and between the burr and the 2 mm Kerrison (p = .001). There was no statistical difference between the 1 mm and 2 mm Kerrison (p = .78). The mean rank of the burr group, the Kerrison rongeur group, and the piecemeal group were 1.41, 1.94, and 2.65, respectively, on an ordinal scale of 1–3. Conclusion: When performing a trough laminotomy, the high-speed burr results in less canal encroachment compared to 1 mm or 2 mm Kerrison rongeurs. In the setting of a stenotic spinal canal, spine surgeons should consider using the burr to perform laminectomy to minimize the degree of canal encroachment.

Intraoperative Ultrasound-Guided Posterior Cervical Laminectomy for Degenerative Cervical Myelopathy

Article

Oct 2018

Objective We present our experience with routine intraoperative ultrasound (IOUS)–guided posterior cervical laminectomy (PCL) in patients with degenerative cervical myelopathy (DCM), describe the technique used, and describe relevant IOUS findings that may impact the surgical procedure. Methods Three illustrative cases are presented of patients (age range, 67–79 years) who underwent PCL with IOUS guidance and instrumented fusion for DCM. Intraoperative standard B-mode images were obtained with a linear array 6.6- to 13.3-MHz transducer. Results Excellent high-resolution IOUS view of the spinal cord and nerve roots was obtained in every case after laminectomy. IOUS had a relevant intraoperative impact in all cases, leading to extended decompression of focal residual compression, confirmation of posterior shift of the spinal cord from anteriorly located structures, and final confirmation of sufficient decompression by visualization of symmetric and rhythmic cord pulsations. Conclusions IOUS is a poorly described yet easy-to-use and very effective tool for guidance and confirmation of adequate posterior decompression of the cervical spinal cord and nerve roots during PCL. Routinely using IOUS-guided decompression for PCL in patients with myelopathy will help avoid residual compression of neural elements and might be beneficial for functional outcome.

Surgical management of cervical spondylotic myelopathy - Indications for anterior, posterior or combined procedures for decompression and stabilisation

Article

Nov 2013
ACTA NEUROCHIR

The authors describe their experience with the choice of anterior, posterior and combined approaches for the surgical treatment of spondylotic myelopathy. Description of surgical anatomy, surgical technique, indications, limitations, complications, specific perioperative considerations and specific information to give to the patient about surgery and potential risks and a summary of 10 key points is given. If the disease extends behind the posterior vertebral body and if reestablishing spinal sagittal and coronal balance is an aim, then the anterior approach is the best choice. In cases of predominant posterior spinal cord compression and lordotic configuration the posterior approach should be preferred. Decompression of three or more levels, especially in combination with poor bone quality, requires a combined approach.

Laminoplasty versus skip laminectomy for the treatment of multilevel cervical spondylotic myelopathy: A systematic review

Article

Nov 2013
ARCH ORTHOP TRAUM SU

Laminoplasty and skip laminectomy are two specific posterior surgical approaches for multilevel cervical spondylotic myelopathy. The objective of this study was to perform a systematic review comparing the clinical results and complications of laminoplasty and skip laminectomy in the treatment of multilevel cervical spondylotic myelopathy. We reviewed and analyzed papers published from January 1969 to December 2012 through the Mediline, Embase, Cochrane review library, and other databases regarding the comparison between laminoplasty and skip laminectomy for multilevel cervical spondylotic myelopathy. One randomized controlled trial and three non-randomized controlled trials were included in this systematic review. In three studies, the preoperative and postoperative JOA score was similar in both laminoplasty and skip laminectomy groups. In addition, for recovery rate, there was no significant difference between the groups. One study reported that, regarding SF12 scores, there was no significant difference in physical health and mental health after surgery. However, regarding cervical pain, the skip laminectomy group was better than the laminoplasty group significantly. No difference was presented in postoperative ROM and the cervical lordosis between the groups. But the ROM % (post/pre) was reported to be significantly better in the skip laminectomy group in three studies. Less blood loss and shorter operation time were observed in skip laminectomy rather than laminoplasty. Based on the results above, the skip laminectomy group presented better outcomes in a variety of aspects: ROM % (post/pre), complication rate, surgical trauma, etc. However, as limited study samples were included in the paper, a claim of superiority of the two approaches could not be justified. Further studies are required on the comparison between laminoplasty and skip laminectomy.

Biomechanical Effects of Laminoplasty Versus Laminectomy: Stenosis and Stability

Article

Full-text available

Jul 2009

Study Design. In vitro human cadaveric study simultaneously quantifying sagittal plane flexibility and spinal canal stenosis. Objective. To compare biomechanical stability and the change in cross-sectional area during flexion and extension after laminectomy and open-door laminoplasty. Summary of Background Data. Spinal canal stenosis has been quantified in vitro but has not been quantified in studies of laminectomy or laminoplasty. Methods. Cadaveric specimens were loaded in physiologic-range flexion and extension using nonconstraining pure moments while recording segmental angles optoelectronically. Custom flexible tubing was placed within the spinal canal, and water was continuously pumped through the tubing while measuring upstream pressure. Spinal canal cross-sectional area correlated to water pressure, allowing continuous monitoring of the smallest cross-sectional area of the canal. Specimens were tested (1) normal, (2) after modeling stenosis by inserting hemispherical wooden beads in the spinal canal at 3 levels, (3) after open-door laminoplasty at 5 levels, and (4) after expanding laminoplasty to laminectomy. Results. Range of motion (ROM) in the normal, stenotic, and laminoplasty conditions did not differ significantly. However, laminectomy increased ROM significantly more than other conditions. ROM after laminectomy was 13% greater than after laminoplasty. After modeling stenosis, the cross-sectional area decreased to 52% ± 12% of normal. Laminoplasty restored the cross-sectional area to 70% ± 12% of normal whereas laminectomy restored cross-sectional area to 101% ± 4% of normal. Among all conditions, areas differed significantly except normal versus laminectomy. Conclusion. Laminoplasty leaves the spine in a significantly more stable condition than laminectomy. However, laminoplasty failed to relieve stenosis completely. In this study, stenosis was modeled as about 50% occlusion of the spinal canal. The degree of stenosis should be considered in clinical decisions of whether laminectomy or laminoplasty is more appropriate.

Cervical Pedicle Subtraction Osteotomy for Fixed Flexion Deformities

Article

Full-text available

Jun 2012
ORTHOPEDICS

Flexion deformities of the cervical spine are multiplanar surgical challenges. This article describes a technical modification during the osteotomy that protects the cervical cord and exiting nerve roots while removing the maximal amount of bone for the osteotomy in the safest fashion.

Posterior cervical decompressive laminectomy and lateral mass screw fixation

Article

Full-text available

Jul 2011

To review the results and complications of cervical decompressive laminectomy and lateral mass screw fixation. This retrospective study was carried out between October 2006 and January 2010 at King Abdullah University Hospital, Irbid, Jordan. Over 40 months, 405 lateral mass screws were placed in 50 patients aged 22-65 years (17 females, and 33 males) for variable cervical pathologies including degenerative disease, trauma, and neoplasm. All cases were performed with a polyaxial screw/rod construct. Most patients had 14 mm length and 3.5 mm diameter screws placed. The screw location was evaluated by postoperative plain x-ray and CT. The facet joint, foraminal and foramen transversarium violation were also assessed. All screws were placed using the Anderson or Sekhon methods. No patients experienced neural or vascular injury as a result of screw position. One patient needed screw repositioning. Three patients experienced superficial wound infection. Five patients experienced pain around the shoulder of C5 distribution that subsided over time. No patients had screw pullouts or symptomatic adjacent segment disease. Postoperative CT scanning showed no compromise of the foramen transversarium or neural foramen in the vast majority of the patients. Lateral mass screw stabilization is a safe and effective surgical technique. This study exhibits the safety and effectiveness of lateral mass fixation for a variety of subaxial cervical spine disease.

Blood supply and vascular reactivity of the spinal cord under normal and pathological conditions A review

Article

Full-text available

Jun 2011
J NEUROSURG-SPINE

The authors present a review of spinal cord blood supply, discussing the anatomy of the vascular system and physiological aspects of blood flow regulation in normal and injured spinal cords. Unique anatomical functional properties of vessels and blood supply determine the susceptibility of the spinal cord to damage, especially ischemia. Spinal cord injury (SCI), for example, complicating thoracoabdominal aortic aneurysm repair is associated with ischemic trauma. The rate of this devastating complication has been decreased significantly by instituting physiological methods of protection. Traumatic SCI causes complex changes in spinal cord blood flow, which are closely related to the severity of injury. Manipulating physiological parameters such as mean arterial blood pressure and intrathecal pressure may be beneficial for patients with an SCI. Studying the physiopathological processes of the spinal cord under vascular compromise remains challenging because of its central role in almost all of the body's hemodynamic and neurofunctional processes.

Decompressive cervical laminectomy and lateral mass screw-rod arthrodesis. Surgical analysis and outcome

Article

Full-text available

May 2011
Scoliosis

This study evaluates the outcome and complications of decompressive cervical Laminectomy and lateral mass screw fixation in 110 cases treated for variable cervical spine pathologies that included; degenerative disease, trauma, neoplasms, metabolic-inflammatory disorders and congenital anomalies. A retrospective review of total 785 lateral mass screws were placed in patients ages 16-68 years (40 females and 70 males). All cases were performed with a polyaxial screw-rod construct and screws were placed by using Anderson-Sekhon trajectory. Most patients had 12-14-mm length and 3.5 mm diameter screws placed for subaxial and 28-30 for C1 lateral mass. Screw location was assessed by post operative plain x-ray and computed tomography can (CT), besides that; the facet joint, nerve root foramen and foramen transversarium violation were also appraised. No patients experienced neural or vascular injury as a result of screw position. Only one patient needed screw repositioning. Six patients experienced superficial wound infection. Fifteen patients had pain around the shoulder of C5 distribution that subsided over the time. No patients developed screw pullouts or symptomatic adjacent segment disease within the period of follow up. decompressive cervical spine laminectomy and Lateral mass screw stabilization is a technique that can be used for a variety of cervical spine pathologies with safety and efficiency.

Erratum to: The stabilizing potential of anterior, posterior and combined techniques for the reconstruction of a 2-level cervical corpectomy model: biomechanical study and first results of ATPS prototyping

Article

Full-text available

Apr 2011
EUR SPINE J

Clinical studies reported frequent failure with anterior instrumented multilevel cervical corpectomies. Hence, posterior augmentation was recommended but necessitates a second approach. Thus, an author group evaluated the feasibility, pull-out characteristics, and accuracy of anterior transpedicular screw (ATPS) fixation. Although first success with clinical application of ATPS has already been reported, no data exist on biomechanical characteristics of an ATPS-plate system enabling transpedicular end-level fixation in advanced instabilities. Therefore, we evaluated biomechanical qualities of an ATPS prototype C4–C7 for reduction of range of motion (ROM) and primary stability in a non-destructive setup among five constructs: anterior plate, posterior all-lateral mass screw construct, posterior construct with lateral mass screws C5 + C6 and end-level fixation using pedicle screws unilaterally or bilaterally, and a 360° construct. 12 human spines C3–T1 were divided into two groups. Four constructs were tested in group 1 and three in group 2; the ATPS prototypes were tested in both groups. Specimens were subjected to flexibility test in a spine motion tester at intact state and after 2-level corpectomy C5–C6 with subsequent reconstruction using a distractable cage and one of the osteosynthesis mentioned above. ROM in flexion–extension, axial rotation, and lateral bending was reported as normalized values. All instrumentations but the anterior plate showed significant reduction of ROM for all directions compared to the intact state. The 360° construct outperformed all others in terms of reducing ROM. While there were no significant differences between the 360° and posterior constructs in flexion–extension and lateral bending, the 360° constructs were significantly more stable in axial rotation. Concerning primary stability of ATPS prototypes, there were no significant differences compared to posterior-only constructs in flexion–extension and axial rotation. The 360° construct showed significant differences to the ATPS prototypes in flexion–extension, while no significant differences existed in axial rotation. But in lateral bending, the ATPS prototype and the anterior plate performed significantly worse than the posterior constructs. ATPS was shown to confer increased primary stability compared to the anterior plate in flexion–extension and axial rotation with the latter yielding significance. We showed that primary stability after 2-level corpectomy reconstruction using ATPS prototypes compared favorably to posterior systems and superior to anterior plates. From the biomechanical point, the 360° instrumentation was shown the most efficient for reconstruction of 2-level corpectomies. Further studies will elucidate whether fatigue testing will enhance the benefit of transpedicular anchorage with posterior constructs and ATPS.

A late neurological complication following posterior correction surgery of severe cervical kyphosis

Article

Full-text available

Oct 2010
EUR SPINE J

Though a possible cause of late neurological deficits after posterior cervical reconstruction surgery was reported to be an iatrogenic foraminal stenosis caused not by implant malposition but probably by posterior shift of the lateral mass induced by tightening screws and plates, its clinical features and pathomechanisms remain unclear. The aim of this retrospective clinical review was to investigate the clinical features of these neurological complications and to analyze the pathomechanisms by reviewing pre- and post-operative imaging studies. Among 227 patients who underwent cervical stabilization using cervical pedicle screws (CPSs), six patients who underwent correction of cervical kyphosis showed postoperative late neurological complications without any malposition of CPS (ND group). The clinical courses of the patients with deficits were reviewed from the medical records. Radiographic assessment of the sagittal alignment was conducted using lateral radiographs. The diameter of the neural foramen was measured on preoperative CT images. These results were compared with the other 14 patients who underwent correction of cervical kyphosis without late postoperative neurological complications (non-ND group). The six patients in the ND group showed no deficits in the immediate postoperative periods, but unilateral muscle weakness of the deltoid and biceps brachii occurred at 2.8 days postoperatively on average. Preoperative sagittal alignment of fusion area showed significant kyphosis in the ND group. The average of kyphosis correction in the ND was 17.6° per fused segment (range 9.7°-35.0°), and 4.5° (range 1.3°-10.0°) in the non-ND group. A statistically significant difference was observed in the degree of preoperative kyphosis and the correction angles at C4-5 between the two groups. The diameter of the C4-5 foramen on the side of deficits was significantly smaller than that of the opposite side in the ND group. Late postoperative neurological complications after correction of cervical kyphosis were highly associated with a large amount of kyphosis correction, which may lead foraminal stenosis and enhance posterior drift of the spinal cord. These factors may lead to both compression and traction of the nerves, which eventually cause late neurological deficits. To avoid such complications, excessive kyphosis correction should not be performed during posterior surgery to avoid significant posterior shift of the spinal cord and prophylactic foraminotomies are recommended if narrow neuroforamina were evident on preoperative CT images. Regardless of revision decompression or observation, the majority of this late neurological complication showed complete recovery over time.

Total subaxial reconstruction: Clinical article

Article

Full-text available

Oct 2010
J NEUROSURG-SPINE

Vincent C Traynelis

Certain cervical spinal conditions require decompression and reconstruction of the entire subaxial cervical spine. There are limited data concerning the clinical details and outcomes of patients treated in this manner. The object of this study was to describe the specific technique employed to perform a total subaxial reconstruction and review the postoperative outcomes following surgery. The author performed a review of data prospectively collected in 27 consecutive patients undergoing complete anterior decompression and reconstruction of the anterior cervical spine and followed by posterior instrumented arthrodesis with or without decompression. There were 16 men and 11 women whose mean age was 59 years (range 35-86 years). The minimum follow-up was 12 months and the mean follow-up period for all patients was 26 months. One patient underwent C2-7 surgery, and in all others the procedure crossed the cervicothoracic junction. Following surgery patients remained intubated for an average of 3.3 days (range 1-22 days). The mean hospital length of stay was 11 days (range 3-45 days). One patient died 6 weeks following an uneventful surgery. Pneumonia developed in 5 patients, 1 patient experienced a minor pulmonary embolism, and 2 patients had posterior wound infections. No patient was neurologically worse following surgery. A single patient presented with a C-8 radiculopathy 6 weeks after surgery. At final follow-up no patient complained of dysphagia when specifically questioned about this potential problem. In all patients solid fusions developed at each treated levels. Preoperatively the mean sagittal Cobb angle was 15.4° (kyphosis) and the postoperative mean angle was -10.9° (lordosis) representing a total average correction of over 25° (p < 0.0001). The mean preoperative Neck Disability Index was 27.6; this score decreased to 15.5 (p = 0.0008) postoperatively. The mean pre- and postoperative visual analog scale neck pain scores were 6.0 and 2.1, respectively (p = 0.0004), and mean visual analog scale arm pain scores decreased by 3.7 following surgery (p = 0.001). Based on Odom criteria, the author found that 8 patients had an excellent outcome and 14 patients a good outcome. There were 4 patients in whom the outcome was judged to be fair and the single death was recorded as a poor outcome. The mean preoperative Nurick score was 2.68. Postoperatively the group improved to an average score of 1.5; the difference between the 2 was statistically significant (p = 0.002). Segmental anterior decompression and reconstruction of the entire subaxial cervical spine, combined with an instrumented posterolateral fusion, can be performed with acceptable morbidity and is of significant benefit in selected patients.

Kyphotic Cervical Deformity Correction

Chapter

Jan 2005

The surgical management of cervical spinal stenosis, spondylosis, and myeloradiculopathy by means of the posterior approach

Article

Jan 1989

Critical analysis of extensive cervical laminectomy

Article

Feb 1989

: Conventional extensive laminectomy has been widely performed to reduce spinal cord compression, and is greatly facilitated by the use of an air drill. Laminectomy is recognized, however, as the occasional cause of problems after surgery, such as spinal instability or deformity, acceleration of spondylotic change, constriction of the dura mater caused by extradural scar formation, and lack of posterior bony protection for the spinal cord. In an effort to eliminate these negative aspects of conventional laminectomy, a surgical technique called suspension laminotomy has been used. Fiftyfive patients treated with conventional extensive laminectomy and 55 others treated with suspension laminotomy were followed up clinically and compared. Flexibility and alignment of the cervical spine were assessed by plane radiographs, and dural configuration by computed tomographic scans. Neurologic improvement was also evaluated. Decrease of spinal movement after laminectomy was observed, notably during extension, probably as a result of functional insufficiency of paraspinal muscles. The incidence of postoperative spinal deformity was lower and the relief of dural constriction better in the patients treated with suspension laminotomy than in those treated with conventional laminectomy. Neurological recovery was significantly better in fully decompressed cases than in insufficiently decompressed cases. (Neurosurgery 24:215-222, 1989) Copyright (C) by the Congress of Neurological Surgeons

Comparison of Transcranial Electric Motor and Somatosensory Evoked Potential Monitoring During Cervical Spine Surgery

Article

Jun 2004

Background: There has been little enthusiasm for somatosensory evoked potential monitoring in cervical spine surgery as a result, in part, of the increased risk of motor tract injury at this level, to which somatosensory monitoring may be insensitive. Transcranial electric motor evoked potential monitoring allows assessment of the motor tracts; therefore, we compared transcranial electric motor evoked potential and somatosensory evoked potential monitoring during cervical spine surgery to determine the temporal relationship between the changes in the potentials demonstrated by each type of monitoring and neurological sequelae and to identify patient-related and surgical factors associated with intraoperative neurophysiological changes. Methods: Somatosensory evoked potential and transcranial electric motor evoked potential data recorded for 427 patients undergoing anterior or posterior cervical spine surgery between January 1999 and March 2001 were analyzed. All patients who showed substantial (at least 60%) or complete unilateral or bilateral amplitude loss, for at least ten minutes, during the transcranial electric motor evoked potential and/or somatosensory evoked potential monitoring were identified. Results: Twelve of the 427 patients demonstrated substantial or complete loss of amplitude of the transcranial electric motor evoked potentials. Ten of those patients had complete reversal of the loss following prompt intraoperative intervention, whereas two awoke with a new motor deficit. Somatosensory evoked potential monitoring failed to identify any change in one of the two patients, and the change in the somatosensory evoked potentials lagged behind the change in the transcranial electric motor evoked potentials by thirty-three minutes in the other. No patient showed loss of amplitude of the somatosensory evoked potentials in the absence of changes in the transcranial electric motor evoked potentials. Transcranial electric motor evoked potential monitoring was 100% sensitive and 100% specific, whereas somatosensory evoked potential monitoring was only 25% sensitive; it was, however, 100% specific. Conclusions: Transcranial electric motor evoked potential monitoring appears to be superior to conventional somatosensory evoked potential monitoring for identifying evolving motor tract injury during cervical spine surgery. Surgeons should strongly consider using this modality when operating on patients with cervical spondylotic myelopathy in general and on those with ossification of the posterior longitudinal ligament in particular. Level of Evidence: Diagnostic study, Level I-1 (testing of previously developed diagnostic criteria in series of consecutive patients [with universally applied reference “gold” standard]). See Instructions to Authors for a complete description of levels of evidence.

Early reconstruction failures after multilevel cervical corpectomy

Article

Jan 2003

Study Design, A retrospective analysis of graft and plate complications after multilevel anterior cervical corpectomy and fusion (ACF) attributed to spondylosis, stenosis, and ossification of posterior longitudinal ligament was conducted. Objective. To identify factors contributing to graft and plate complications in this population. Summary of Background Data. Biomechanical factors contributing to the increased morbidity associated with plated multilevel ACF were evaluated. Methods. Graft- and/or plate-related complications were retrospectively reviewed in 33 patients undergoing two-level ACF reconstructions and in seven patients having three-level ACF reconstructions performed with iliac crest grafting and instrumentation with a fixed-plated design (cervical spine locking plate). Neurologic status was assessed before surgery and after surgery using bath the Nurick Grading Scale and modified JOA (Japanese Orthopaedic Association) Score. The patients were observed an average of 31.4 months after surgery. The follow-up included lateral flexion and extension radiographs and a neurologic examination. Results. Two of the 33 patients undergoing two-level fusions available for long-term follow-up after surgery developed reconstruction failures. All of the remaining fusions were successful, demonstrated by lateral flexion and extension radiographs. Seven patients had plated three-level corpectomy reconstructions. Five of the seven who had anterior-only reconstruction failed. Discussion. A two-level ACF reconstruction is reliable With an anterior strut graft and fixed screw plate construct. A three-level ACF reconstruction is not reliably achieved with an anterior-only construct The construct failures may be attributed in part to the fixed-plated design being used, as well as the long lever arm of the construct. Conclusion. There is a 6% failure rate after fixed-plated (cervical spine locking plate) two-level ACF reconstruction but a 71% failure rate after three-level fixed-plated ACF reconstruction. Future consideration should be given to simultaneous posterior fusion.

Cervical Spondylotic Radiculopathy and Myelopathy

Article

Sep 1976
ARCH NEUROL-CHICAGO

F. Karl Gregorius

• The natural history of cervical spondylotic myelopathy in a series of 55 patients resulted in a moderate to severe disability during a mean period of 45 months. Results of operation for myelopathy indicated improvement in one group that was maintained for a mean of 85 months. In another group, progressive worsening occurred after operation, or late worsening occurred, in some instances as long as 8 to 12 years after improvement and plateau. Patients with cervical spondylotic radiculopathy tended to be separated from those with myelopathy with respect to presentation, symptom complex, and operative result. Results of operation for radiculopathy were consistently good.A worsened disability postoperatively for patients with cervical spondylotic myelopathy was associated with the preoperative symptom of sphincter disturbance and the sign of lower extremity weakness. Change in hand movement after operation for myelopathy and change in distance walking ability were not correlated with numerous preoperative factors. A trend of improvement in disability following anterior interbody fusion and a tendency to worsen in disability following all varieties of laminectomy were significant.

Cervical laminoplasty: a critical review

Article

Apr 2003
J NEUROSURG

Object. The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multilevel anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the "postlaminectomy membrane." Methods. The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients. All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20-80%). The authors of 23 papers provided data on the percentage of patients improving (mean -80%). There was no difference in neurological outcome based on the different laminoplasty techniques or when laminoplasty was compared with laminectomy. There was postlaminoplasty worsening of cervical alignment in approximately 35% and with development of postoperative kyphosis in approximately 10% of patients who underwent long-term follow-up review. Cervical ROM decreased substantially after laminoplasty (mean decrease 50%, range 17-80%). The authors of studies with long-term follow up found that there was progressive loss of cervical ROM, and final ROM similar to that seen in patients who had undergone laminectomy and fusion. In their review of the laminectomy literature the authors could not confirm the occurrence of postlaminectomy membrane causing clinically significant deterioration of neurological function. Postoperative complications differed substantially among series. In only seven articles did the writers quantify the rates of postoperative axial neck pain, noting an incidence between 6 and 60%. In approximately 8% of patients, C-5 nerve root dysfunction developed based on the 12 articles in which this complication was reported. Conclusions. The literature has yet to support the purported benefits of laminoplasty. Neurological outcome and change in spinal alignment are similar after laminectomy and laminoplasty. Patients treated with laminoplasty develop progressive limitation of cervical ROM similar to that seen after laminectomy and fusion.

COMPLICATIONS OF CERVICAL-SPINE SURGERY - A 5-YEAR REPORT ON A SURVEY OF THE MEMBERSHIP OF THE CERVICAL-SPINE-RESEARCH-SOCIETY BY THE MORBIDITY-AND-MORTALITY-COMMITTEE

Article

Oct 1989

JJ GRAHAM

The Anatomic Relation of Lateral Mass Screws to the Spinal Nerves

Article

Oct 1999

Study Design. Analysis of the anatomic relation of the Magerl, Anderson, and An screws to the spinal nerve. Objectives. To compare the potential incidence of nerve root (ventral and dorsal ramus) injury caused by the Magerl, Anderson, and An techniques. Summary of Background Data. Posterior plating with lateral mass screw fixation is a common procedure for managing an unstable cervical spine. Comparative study of the Roy-Camille and Magerl techniques has been reported. However, the risk of nerve root injury for the Anderson and An techniques is not known. Methods. Three lateral mass screw insertion techniques were performed in this study: Magerl, Anderson, and An. Each technique involved two specimens and 20 screws inserted from C3 through C7. A 20-mm–long screw was used to overpenetrate the ventral cortex. The anterolateral aspect of the cervical spine was carefully dissected to allow observation of the screw–ramus relationship. Results. The overall percentage of nerve violation was significantly higher with the Magerl (95%) and Anderson (90%) techniques than with the An (60%) technique (P < 0.05). The largest percentages of nerve violation for the Magerl, Anderson, and An screws were found at the dorsal ramus (50%), the bifurcation of the ventral dorsal ramus (45%), and the ventral ramus (55%), respectively. Conclusions. The results of this study indicate that the potential risk of nerve root violation is higher with the Magerl and Anderson techniques than with the An technique.

Posterior Cervical Lateral Mass Screw Fixation

Article

Aug 2005
J SPINAL DISORD TECH

Lali H S Sekhon

Objective: This study evaluates the results and complications of 1026 consecutive lateral mass screws inserted in 143 patients by a single surgeon. Methods: Over a 50-month period, a total of 1026 lateral mass screws were placed in 143 patients ages 12-96 years (56 females and 87 males), with these records retrospectively reviewed. Screw position was evaluated by computed tomography (CT) scanning postoperatively, with screw positions assessed for facet, foraminal, or foramen transversarium violation. Results: All screws were placed by a modification of the Anderson technique, but 20 screws were converted to Roy-Camille trajectories because of screw pullout. No patients experienced neural injury or vertebral artery injury as a result of screw placement. Three patients had screw pullouts using the Axis system, which did not require reoperation. Most patients had 14-mm screws placed. Postoperative CT scanning showed no compromise of the foramen transversarium or neural foramen. A total of 94 C7 lateral mass screws were placed without the need for pedicle screws at this level. Forty-four cases were performed with a screw/plate construct with the remainder performed using a polyaxial screw/rod construct. One patient had a symptomatic adjacent-level disc herniation that required surgical intervention. One patient required extension of laminectomy for residual compression. Conclusions: Lateral mass screw fixation is a safe and effective stabilization technique. This study demonstrates the safety and efficacy of lateral mass cannulation for a range of cervical pathologies with the largest reported series of consecutive lateral mass screws in the literature. In most cases of subaxial disease, nonconstrained plate/screw systems provide a reasonable alternative to polyaxial screw/rod constructs. Most patients can be fixated with 14-mm length × 3.5-mm diameter screws. The C7 lateral mass can be drilled with an adjusted trajectory.

Cervical Pedicle Screws Versus Lateral Mass Screws

Article

May 1997

Study Design. Biomechanical comparison of the pull-out strengths of lateral mass and pedicle screws in the human cervical spine. Measurements of pedicle dimensions and orientation were compiled. Objectives. To determine if transpedicular screws provide greater pull-out resistance than lateral mass screws and to investigate the anatomic feasibility of pedicle screw insertion. Summary of Background Data. Cervical pedicle screws have been reported in limited clinical and biomechanical studies, and some quantitative cervical pedicle anatomy has been reported. No direct biomechanical comparisons have been made between lateral mass and pedicle screws. Methods. Fifty-six fresh disarticulated human vertebrae (C2-C7) were evaluated with computed tomography to determine morphometry and vertebral body bone density. Lateral mass and pedicle screws were randomized to left versus right. A 3.5-mm cortical screw was used for both techniques, unless a pedicle was narrower than 5.0 mm; then a 2.7-mm cortical screw was used instead. Pedicle wall violations were recorded. Screws were subjected to a uniaxial load to failure. Mean pedicle height, width, and angle with respect to the vertebral midline were tabulated for each level. Results. The mean load-to-failure was 677 N for the cervical pedicle screws and 355 N for the lateral mass screws. No significant correlations for either screw type were found between pull-out strength and bone density, screw length, or vertebral level. Pedicle and lateral mass dimensions were highly variable and not predictive of pull-out strength. Seven (13%) minor pedicle wall violations were observed. Conclusions. Cervical pedicle screws demonstrated a significantly higher resistance to pull-out forces than did lateral mass screws. The variability in pedicle morphometry and orientation requires careful preoperative assessment to determine the suitability of pedicle screw insertion.

Laminoplasty Versus Laminectomy and Fusion for Multilevel Cervical Myelopathy

Article

Jun 2001

Study Design. A matched cohort clinical and radiographic retrospective analysis of laminoplasty and laminectomy with fusion for the treatment of multilevel cervical myelopathy. Objectives. To compare the clinical and radiographic outcomes of two procedures increasingly used to treat multilevel cervical myelopathy. Summary of Background Data. Traditional methods of treating multilevel cervical myelopathy (laminectomy and corpectomy) are reported to have a notable frequency of complications. Laminoplasty and laminectomy with fusion have been advocated as superior procedures. A comparative study of these two techniques has not been reported. Methods. Medical records of all patients treated for multilevel cervical myelopathy with either laminoplasty or laminectomy with fusion between 1994 and 1999 at our institution were reviewed. Thirteen patients that underwent laminectomy with fusion were matched with 13 patients that underwent laminoplasty. All patients and radiographs were independently evaluated at latest follow-up by a single physician. Results. Cohorts were well matched based on patient age, duration of symptoms, and severity of myelopathy (Nurick grade) before surgery. Mean independent follow-up was similar (25.5 and 26.2 months). Both objective improvement in patient function (Nurick score) and the number of patients reporting subjective improvement in strength, dexterity, sensation, pain, and gait tended to be greater in the laminoplasty cohort. Whereas no complications occurred in the laminoplasty cohort, there were 14 complications in 9 patients that underwent laminectomy with fusion patients. Complications included progression of myelopathy, nonunion, instrumentation failure, development of a significant kyphotic alignment, persistent bone graft harvest site pain, subjacent degeneration requiring reoperation, and deep infection. Conclusions. The marked difference in complications and functional improvement between these matched cohorts suggests that laminoplasty may be preferable to laminectomy with fusion as a posterior procedure for multilevel cervical myelopathy.

Visual Loss as a Complication of Spine Surgery

Article

Jun 1997

Study Design. Thirty-seven patients who experienced visual loss after spine surgery were identified through a survey of the members of the Scoliosis Research Society and a review of the recent literature. Objectives. Records were reviewed in an attempt to identify preoperative and intraoperative risk factors and to assess the likelihood of recovery. Summary of Background Data. Postoperative blindness after spine surgery has been documented in case reports or small series. The authors report the largest group of such cases to date and the first to allow conclusions regarding risk and prognosis. Methods. Letters were sent to members of the Scoliosis Research Society requesting copies of medical records concerning patients who experienced postoperative visual deficits after spine surgery. An additional 10 well-documented recent cases were identified from published reports. Results. Patients with visual loss had a mean age of 46.5 years. Surgery included instrumented posterior fusion in 92% of the cases, with an average operative time of 410 minutes and blood loss of 3500 mL. Most cases had significant intraoperative hypotension, with a mean drop in systolic blood pressure from 130 to 77 mm Hg. However, comparison with a matched group of patients with no visual symptoms showed no differences in the hematocrit or blood pressure values. Visual loss occurred because of ischemic optic neuropathy, retinal artery occlusion, or cerebral ischemia. Eleven cases were bilateral, and 15 patients had complete blindness in at least one eye. Most deficits were permanent. Conclusions. The authors conclude that blindness after spine surgery is more common than has been recognized previously. Most cases are associated with complex instrumented fusions.

Evaluation of Prognostic Factors Following Expansive Laminoplasty for Cervical Spinal Stenotic Myelopathy

Article

Sep 1997
SURG NEUROL

Expansive laminoplasty of several types has been proposed for patients with cervical multisegmental stenotic myelopathy to reduce postlaminectomy complications. Its effectiveness has not been fully explored by evaluating long-term results and magnetic resonance imaging (MRI) findings before and after surgery. We conducted a 5-year follow-up study of 22 patients with cervical spondylotic myelopathy and/or ossification of the posterior longitudinal ligament surgically treated with expansive laminoplasty. The operative results were examined using the Japanese Orthopedic Association (JOA) disability scale, with reference to the findings of MRI, computed tomography, and radiography. Postoperative improvement was observed in 18 (81.8%) of the 22 patients. In 11 patients the percentage recovery of the JOA score was higher than 50% (average: 83.1%), while in the remaining 11 patients it was lower than 50% (average: 20.1%). Factors contributing to incomplete recovery appear to be related mainly to cord degeneration with atrophy (depicted as a T2-high intensity area) and to specific factors such as long symptom duration, age higher than 70 years, deterioration due to trauma, severe cord compression, radiculopathy, and kyphotic cervical curvature. In cervical myelopathy, patients with multisegmental stenosis, expansive laminoplasty can be expected to provide a favorable outcome by providing sufficient cord decompression and stabilization of the cervical spine, when the stenotic cervical canal is enlarged to the normal range (over 12 mm residual anteroposterior diameter and 200 mm2 residual canal area). The efficacy can be restricted by various factors, especially irreparable cord degeneration.

Natural History of Cervical Spondylotic Myelopathy

Article

Mar 2007
Semin Spine Surg

Cervical spondylotic myelopathy (CSM) is a serious degenerative spinal condition that can lead to significant functional disability or paralysis. In cases of progressive neurological deficit from CSM, the recommended treatment is surgical decompression, sometimes including stabilization. The potential role of surgery or other treatments in milder cases of CSM depends upon many factors, including the natural history of the untreated condition. This chapter will examine the available data on the natural history of cervical spondylotic myelopathy, as well as its pathophysiology. Such knowledge will enable the clinician and surgeon to better guide the patient in deciding most appropriate choice of treatment options.

Wound Healing and Infection in Surgery: The Pathophysiological Impact of Smoking, Smoking Cessation, and Nicotine Replacement Therapy: A Systematic Review

Article

Dec 2012
J UROLOGY

Richard K Babayan

Effectiveness of 3 Surgical Decompression Strategies for Treatment of Multilevel Cervical Myelopathy in 3 Spinal Centers in China A Retrospective Study

Article

Aug 2012
SPINE

Retrospective multicenter study. To compare clinical outcomes and surgical-related adverse events in patients with multilevel cervical myelopathy (MCM) undergoing simple anterior, simple posterior, or 1-stage posterior-anterior surgical decompression strategies. Simple anterior, simple posterior, and 1-stage posterior-anterior surgical decompression strategies have been advocated for MCM treatment in both Western and Chinese populations. However, there is limited evidence on whether 1-stage posterior-anterior strategy may offer equal or more advantages than the other 2 strategies for patients with MCM. A retrospective review of medical records was conducted for 255 patients with MCM who had undergone surgical decompression in 3 Chinese spinal centers from 1999 to 2010. Neurological status, perioperative variables, and surgical complications were assessed. Multiple linear regression was used to evaluate factors associated with the outcomes of each strategy. Analyses were conducted on a total of 229 patients with MCM undergoing surgical decompression via 1-stage posterior-anterior (68 patients), simple anterior (102 patients), and simple posterior approaches (59 patients). One-stage posterior-anterior approach had the highest Japanese Orthopaedic Association recovery rate after adjusted for age and sex (adjusted mean ± SD: 50.0 ± 3.2, P < 0.001) and additionally adjusted for smoking, duration from onset of symptoms to surgery, comorbidities, preoperative Japanese Orthopaedic Association score, Ishihara's curvature index and Pavlov ratio, operative blood loss, operating time, anterior operated disc levels, and posterior operated levels (adjusted mean ± SD: 51.6 ± 11.6, P < 0.01). Anterior approach had the largest difference between the pre- and postoperative Ishihara's curvature indexes after adjusted for age and sex (adjusted mean ± SD: 5.3 ± 1.0, P < 0.01) and after multivariable adjustment (adjusted mean ± SD: 6.5 ± 2.8, P = 0.003). One-stage posterior-anterior strategy can be a reliable and effective treatment strategy for MCM in a subgroup of patients with anterior and posterior compression on spinal cord simultaneously.

Lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy: A magnetic resonance imaging study

Article

Sep 1996

We investigated lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy. Fifty-five patients (32 men and 23 women) were studied, with an average follow-up of 2.4 years. Radiological examination included evaluation of lordosis of the cervical spine and spinal cord, degree of enlargement of bony spinal canal, and the magnitude of posterior cord migration. We also correlated these changes with neurological improvement. Postoperatively, there was an average of 5% loss of cervical spine lordosis (P > 0.01) on radiographs and 12% reduction in the lordotic alignment of the spinal cord (P > 0.05) on magnetic resonance imaging. Postoperatively, the size of the bony spinal canal increased by 48%. Posterior cord migration showed a significant correlation with the preoperative cervical spine and spinal cord lordosis (P < 0.05).="" thirty-seven="" (67%)="" patients="" with="" neurological="" improvement="" exceeding="" 50%="" showed="" significant="" posterior="" cord="" migration="" following="" laminoplasty="" compared="" with="" those="" demonstrating="" less="" than="" 50%="" improvement="">P = 0.01). Our results suggest that a significant neurological improvement is associated with posterior cord migration after cervical laminoplasty.

Morphological Features and Clinical Significance of Epidural Membrane in the Cervical Spine

Article

May 2012
SPINE

A prospective clinical study. To elucidate the histomorphological features and clinical significance of the epidural membrane (EM) in the cervical spine based on operative and histological findings. The anatomical features of the EM have been mostly discussed on the basis of cadaver studies in the whole spine. However, the histomorphological features and clinical significance of the EM in the cervical spine based on operative findings have never been reported. Eighty-seven patients with cervical spondylotic myelopathy who had undergone an expansive open-door laminoplasty under microscopy were evaluated with a more than 2-year follow-up period. The most damaged spinal segment was determined in each patient from the preoperative neurological and image findings along with the remaining symptoms at follow-up. The morphological features of the EM were observed and recorded in each patient during decompression. For histology, specimens of common and remarkable types of the EM obtained from 16 patients were examined. The age at surgery averaged 64.5 years; there were 58 men and 29 women. With regard to the most damaged spinal segment, there were 14 cases at the C3-C4 level, 37 at the C4-C5 level, 32 at the C5-C6 level, and 4 at the C6-C7 level. The EM was an adipo-fibro-vascular tissue with various histomorphologies, blending with the periradicular sheath. Some EMs showed notable findings: obstructing dural tube expansion (13 cases, 14.9%), compressing a nerve root or disturbing its mobility (4 cases, 4.6%), and the combined type (1 case, 1.1%). All of them were located at approximately the most damaged spinal segment. In addition, some EMs had interesting histological features, such as harboring many small arteries, calcified debris, and metaplastic bone fragments. The EM can develop into remarkable structures with spondylosis and aging in patients with cervical spondylotic myelopathy, affecting surgical outcomes as well as successful decompression procedures. A sound understanding of the histomorphological features of the EM is required to obtain satisfactory surgical outcomes in the limited field afforded by minimally invasive surgery.

Analysis of NHSLA claims in orthopedic surgery

Article

May 2012
ORTHOPEDICS

National Health Service (NHS) statistics in the United Kingdom demonstrate an increase in clinical negligence claims over the past 30 years. Reasons for this include elements of a cultural shift in attitudes toward the medical profession and the growth of the legal services industry. This issue affects medical and surgical health providers worldwide. The authors analyzed 2117 NHS Litigation Authority (NHSLA) orthopedic surgery claims between 1995 and 2001 with respect to these clinical areas: emergency department, outpatient care, surgery (elective or trauma operations), and inpatient care. The authors focused on the costs of settling and defending claims, costs attributable to clinical areas, common causes of claims, and claims relating to elective or trauma surgery. Numbers of claims and legal costs increased most notably in surgery (elective and trauma) and in the emergency department. However, claims are being defended more robustly. The annual cost for a successful defense has remained relatively stable, showing a slight decline. The common causes of claims are postoperative complication; wrong, delayed, or failure of diagnosis; inadequate consent; and wrong-site surgery. Certain surgical specialties (eg, spine and lower-limb surgery) have the most claims made during elective surgery, whereas upper-limb surgery has the most claims made during trauma surgery. The authors recommend that individual trusts liaise with orthopedic surgeons to devise strategies to address areas highlighted in our study. Despite differences in health care systems worldwide, the underlying issues are common. With improved understanding, physicians can deliver the service they promise their patients.

Wound Healing and Infection in Surgery: The Pathophysiological Impact of Smoking, Smoking Cessation, and Nicotine Replacement Therapy A Systematic Review

Article

May 2012
ANN SURG

Lars Tue Sørensen

The aim was to clarify how smoking and nicotine affects wound healing processes and to establish if smoking cessation and nicotine replacement therapy reverse the mechanisms involved. Smoking is a recognized risk factor for healing complications after surgery, but the pathophysiological mechanisms remain largely unknown. Pathophysiological studies addressing smoking and wound healing were identified through electronic databases (PubMed, EMBASE) and by hand-search of articles' bibliography. Of the 1460 citations identified, 325 articles were retained following title and abstract reviews. In total, 177 articles were included and systematically reviewed. Smoking decreases tissue oxygenation and aerobe metabolism temporarily. The inflammatory healing response is attenuated by a reduced inflammatory cell chemotactic responsiveness, migratory function, and oxidative bactericidal mechanisms. In addition, the release of proteolytic enzymes and inhibitors is imbalanced. The proliferative response is impaired by a reduced fibroblast migration and proliferation in addition to a downregulated collagen synthesis and deposition. Smoking cessation restores tissue oxygenation and metabolism rapidly. Inflammatory cell response is reversed in part within 4 weeks, whereas the proliferative response remains impaired. Nicotine does not affect tissue microenvironment, but appears to impair inflammation and stimulate proliferation. Smoking has a transient effect on the tissue microenvironment and a prolonged effect on inflammatory and reparative cell functions leading to delayed healing and complications. Smoking cessation restores the tissue microenvironment rapidly and the inflammatory cellular functions within 4 weeks, but the proliferative response remain impaired. Nicotine and nicotine replacement drugs seem to attenuate inflammation and enhance proliferation but the effect appears to be marginal.

Pedicle Subtraction Osteotomy in the Cervical Spine

Article

Mar 2012
SPINE

Description of surgical technique with review of literature. To describe the surgical management of cervical spine deformity, using pedicle subtraction osteotomy. Previous articles have primarily described Smith-Petersen osteotomies and Simmons' modifications to correct fixed cervical deformity. Those were typically performed with the patient awake and sedated in a seated position and without the use of spinal instrumentation. Description of a single surgeon's technique for performing pedicle subtraction osteotomy to treat fixed cervical deformity. The use of pedicle subtraction osteotomy in the cervical spine is a safe and effective procedure when performed by experienced surgeons and can result in a satisfying outcome for both the patient and the surgeon.

Perioperative and delayed complications associated with the surgical treatment of cervical spondylotic myelopathy based on 302 patients from the AOSpine North America Cervical Spondylotic Myelopathy Study

Article

Feb 2012
J NEUROSURG-SPINE

Rates of complications associated with the surgical treatment of cervical spondylotic myelopathy (CSM) are not clear. Appreciating these risks is important for patient counseling and quality improvement. The authors sought to assess the rates of and risk factors associated with perioperative and delayed complications associated with the surgical treatment of CSM. Data from the AOSpine North America Cervical Spondylotic Myelopathy Study, a prospective, multicenter study, were analyzed. Outcomes data, including adverse events, were collected in a standardized manner and externally monitored. Rates of perioperative complications (within 30 days of surgery) and delayed complications (31 days to 2 years following surgery) were tabulated and stratified based on clinical factors. The study enrolled 302 patients (mean age 57 years, range 29-86) years. Of 332 reported adverse events, 73 were classified as perioperative complications (25 major and 48 minor) in 47 patients (overall perioperative complication rate of 15.6%). The most common perioperative complications included minor cardiopulmonary events (3.0%), dysphagia (3.0%), and superficial wound infection (2.3%). Perioperative worsening of myelopathy was reported in 4 patients (1.3%). Based on 275 patients who completed 2 years of follow-up, there were 14 delayed complications (8 minor, 6 major) in 12 patients, for an overall delayed complication rate of 4.4%. Of patients treated with anterior-only (n = 176), posterior-only (n = 107), and combined anterior-posterior (n = 19) procedures, 11%, 19%, and 37%, respectively, had 1 or more perioperative complications. Compared with anterior-only approaches, posterior-only approaches had a higher rate of wound infection (0.6% vs 4.7%, p = 0.030). Dysphagia was more common with combined anterior-posterior procedures (21.1%) compared with anterior-only procedures (2.3%) or posterior-only procedures (0.9%) (p < 0.001). The incidence of C-5 radiculopathy was not associated with the surgical approach (p = 0.8). The occurrence of perioperative complications was associated with increased age (p = 0.006), combined anterior-posterior procedures (p = 0.016), increased operative time (p = 0.009), and increased operative blood loss (p = 0.005), but it was not associated with comorbidity score, body mass index, modified Japanese Orthopaedic Association score, smoking status, anterior-only versus posterior-only approach, or specific procedures. Multivariate analysis of factors associated with minor or major complications identified age (OR 1.029, 95% CI 1.002-1.057, p = 0.035) and operative time (OR 1.005, 95% CI 1.002-1.008, p = 0.001). Multivariate analysis of factors associated with major complications identified age (OR 1.054, 95% CI 1.015-1.094, p = 0.006) and combined anterior-posterior procedures (OR 5.297, 95% CI 1.626-17.256, p = 0.006). For the surgical treatment of CSM, the vast majority of complications were treatable and without long-term impact. Multivariate factors associated with an increased risk of complications include greater age, increased operative time, and use of combined anterior-posterior procedures.

Reconstruction of the Subaxial Cervical Spine Using Lateral Mass and Facet Screw Instrumentation

Article

Jan 2012
SPINE

Review article. To review the indications, technical details, and complications of lateral mass and transfacet mass fixation methods. Potential advantages of rigid fixation in subaxial cervical spine have been defined as early mobilization, faster healing and fusion, and increased fusion rates. Lateral mass screw fixation has been the most popular fixation technique for posterior instrumentation. Transfacet screw fixation, on the other hand, is an alternative method less commonly used. Narrative and review of the literature. Several different techniques aiming for the most safe and secure lateral mass screw fixation have been described by several different authors. Lateral mass screws provide rigid fixation and high fusion rates in patients with healthy bone. Complications are rare when patients' anatomy is well documented and proper technique is used. Transfacet screw fixation is another method less commonly used and with better biomechanical stability. Lateral mass screw provides excellent 3-dimensional fixations from C3 to C7, and currently it is also the most commonly performed posterior fixation method.

Cage subsidence does not, but cervical lordosis improvement does affect the long-term results of anterior cervical fusion with stand-alone cage for degenerative cervical disc disease: A retrospective study

Article

Dec 2011
EUR SPINE J

Clinical outcomes of the stand-alone cage have been encouraging when used in anterior cervical discectomy and fusion (ACDF), but concerns remain regarding its complications, especially cage subsidence. This retrospective study was undertaken to investigate the long-term radiological and clinical outcomes of the stand-alone titanium cage and to evaluate the incidence of cage subsidence in relation to the clinical outcome in the surgical treatment of degenerative cervical disc disease. A total of 57 consecutive patients (68 levels) who underwent ACDF using a titanium box cage for the treatment of cervical radiculopathy and/or myelopathy were reviewed for the radiological and clinical outcomes. They were followed for at least 5 years. Radiographs were obtained before and after surgery, 3 months postoperatively, and at the final follow-up to determine the presence of fusion and cage subsidence. The Cobb angle of C2-C7 and the vertebral bodies adjacent to the treated disc were measured to evaluate the cervical sagittal alignment and local lordosis. The disc height was measured as well. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score for cervical myelopathy, before and after surgery, and at the final follow-up. The recovery rate of JOA score was also calculated. The Visual Analogue Scale (VAS) score of neck and radicular pain were evaluated as well. The fusion rate was 95.6% (65/68) 3 months after surgery. Successful bone fusion was achieved in all patients at the final follow-up. Cage subsidence occurred in 13 cages (19.1%) at 3-month follow-up; however, there was no relation between fusion and cage subsidence. Cervical and local lordosis improved after surgery, with the improvement preserved at the final follow-up. The preoperative disc height of both subsidence and non-subsidence patients was similar; however, postoperative posterior disc height (PDH) of subsidence group was significantly greater than of non-subsidence group. Significant improvement of the JOA score was noted immediately after surgery and at the final follow-up. There was no significant difference of the recovery rate of JOA score between subsidence and non-subsidence groups. The recovery rate of JOA score was significantly related to the improvement of the C2-C7 Cobb angle. The VAS score regarding neck and radicular pain was significantly improved after surgery and at the final follow-up. There was no significant difference of the neck and radicular pain between both subsidence and non-subsidence groups. The results suggest that the clinical and radiological outcomes of the stand-alone titanium box cage for the surgical treatment of one- or two-level degenerative cervical disc disease are satisfactory. Cage subsidence does not exert significant impact upon the long-term clinical outcome although it is common for the stand-alone cages. The cervical lordosis may be more important for the long-term clinical outcome than cage subsidence.

Neurological Complications of Cervical Spine Surgery C5 Palsy and Intraoperative Monitoring

Article

Dec 2011
SPINE

Bradford L. Currier

Review article. To review the epidemiology, etiology, risk factors, prevention, and treatment of neurological complications associated with cervical spine surgery. The article focuses on C5 palsy and intraoperative neurophysiological monitoring. Neurological problems are the complications most feared by patients and surgeons alike, but, fortunately, spinal cord injury is uncommon. C5 palsy is a less severe but much more common and perplexing problem. Intraoperative monitoring is widely used in cervical spine surgery, but it is unclear how effective it is at preventing spinal cord or nerve root injury. Narrative and review of the literature. The incidence of new, severe motor weakness in 2 or more extremities occurring within 12 hours of surgery is 0.18%. The rate in the cervical spine is 3 of 1000. The incidence of isolated C5 palsy is much greater; the rate varies between 0% and 30%, depending on how the condition is defined and which patient group is being analyzed. Numerous theories have been postulated to explain the pathogenesis of C5 palsy, and preventative strategies are discussed. Approximately 70% of patients recover completely without treatment. The mean time to full recovery is 4 to 5 months. Recovery is spontaneous; no treatment has been shown to shorten the time to recovery or improve the recovery rate. A systematic review of the literature found a high level of evidence that multimodal intraoperative monitoring is effective at detecting intraoperative neurological injury. The evidence that intraoperative monitoring reduces the rate of new or worsened perioperative neurological deficits is not as strong. Algorithms help surgeons respond to monitoring alerts and manage neurological deficits that are identified postoperatively. The keys to managing neurological complications in cervical spine surgery are prevention through careful planning, appropriate multimodal monitoring, meticulous surgical technique, and decisive action when a problem is identified.

Laminectomy, durotomy, and piotomy effects on spinal cord intramedullary pressure in severe cervical and thoracic kyphotic deformity: A cadaveric study. Laboratory investigation

Article

Nov 2011
J NEUROSURG-SPINE

Previous studies have shown that cervical and thoracic kyphotic deformity increases spinal cord intramedullary pressure (IMP). Using a cadaveric model, the authors investigated whether posterior decompression can adequately decrease elevated IMP in severe cervical and thoracic kyphotic deformities. Using an established cadaveric model, a kyphotic deformity was created in 16 fresh human cadavers (8 cervical and 8 thoracic). A single-level rostral laminotomy and durotomy were performed to place intraparenchymal pressure monitors in the spinal cord at C-2, C4-5, and C-7 in the cervical study group and at T4-5, T7-8, and T11-12 in the thoracic study group. Intramedullary pressure was recorded at maximal kyphosis. Posterior laminar, dural, and pial decompressions were performed while IMP was monitored. In 2 additional cadavers (1 cervical and 1 thoracic), a kyphotic deformity was created and then corrected. The creation of the cervical and thoracic kyphotic deformities resulted in significant increases in IMP. The mean increase in cervical and thoracic IMP (change in IMP [ΔIMP]) for all monitored levels was 37.8 ± 7.9 and 46.4 ± 6.4 mm Hg, respectively. After laminectomies were performed, the mean cervical and thoracic IMP was reduced by 22.5% and 18.5%, respectively. After midsagittal durotomies were performed, the mean cervical and thoracic IMP was reduced by 62.8% and 69.9%, respectively. After midsagittal piotomies were performed, the mean cervical and thoracic IMP was reduced by 91.3% and 105.9%, respectively. In 2 cadavers in which a kyphotic deformity was created and then corrected, the ΔIMP increased with the creation of the deformity and returned to zero at all levels when the deformity was corrected. In this cadaveric study, laminar decompression reduced ΔIMP by approximately 15%-25%, while correction of the kyphotic deformity returned ΔIMP to zero. This study helps explain the pathophysiology of myelopathy in kyphotic deformity and the failure of laminectomy alone for cervical and thoracic kyphotic deformities with myelopathy. In addition, the study emphasizes the need for correction of deformity during operative treatment of kyphotic deformity, the need for maintaining adequate intraoperative blood pressure during operative treatment, and the higher risk of spinal cord injury associated with operative treatment of kyphotic deformity.

Morbid Obesity Increases Cost and Complication Rates in Spinal Arthrodesis

Article

Oct 2011
SPINE

A retrospective cross-sectional study of all spinal fusions in California from 2003 to 2007. This study analyzes whether morbid obesity alters rates of complications and charges in patients undergoing spinal fusion. Prior studies of obesity have focused on lumbar fusion; some identified increases in wound complications. However, these studies typically do not account for comorbidities, do not examine nonlumbar fusions, and usually are small single institution series. Our study used the Healthcare Cost and Utilization Project's California State Inpatient Databases (CA-SID) to identify normal weight and morbidly obese patients admitted in California between 2003 and 2007 for 4 types of spinal fusion: anterior cervical fusion (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] procedure code 810.2), posterior cervical fusion (810.3), anterior lumbar fusion (810.6), and posterior lumbar fusion (810.8). Demographic, comorbidity, and complications data were collected. Primary outcome was in-hospital complication; secondary outcomes were total cost, length of stay, and in-hospital mortality. Multivariate logistic regression was performed. In total 84,607 admissions were identified, of which 1455 were morbidly obese. Morbid obesity was associated with 97% higher in-hospital complication rates (13.6% vs. 6.9%), sustained across nearly all complication types (cardiac, renal, pulmonary, wound complications, among others). Mortality among the morbidly obese was slightly higher (0.41 vs. 0.13, P < 0.01) as were average hospital costs (

108,604 vs.

84,861, P < 0.0001). Length of stay was longer as well (4.8 d vs. 3.5 d, P < 0.0001). All effects were less pronounced in posterior cervical fusions. On multivariate analysis, morbid obesity was the most significant predictor of complications in the anterior cervical and posterior lumbar fusion groups (more than age, demography, and other comorbidity). Morbid obesity seems to increase the risk of multiple complication types in spinal fusion surgery, most particularly in anterior cervical and posterior lumbar approaches.

Long-term follow-up of cervical radiographic sagittal spinal alignment after 1- and 2-level cervical corpectomy for the treatment of spondylosis of the subaxial cervical spine causing radiculomyelopathy or myelopathy: A retrospective study: Clinical article

Article

Jan 2012
J NEUROSURG-SPINE

Few data exist regarding long-term outcomes after cervical corpectomy for spondylotic cervical myelopathy and radiculomyelopathy. In this retrospective review, long-term radiographic outcomes are reported for 130 patients after 1- or 2-level cervical corpectomy for spondylotic myelopathy or radiculomyelopathy. Electronic medical records including clinical data and radiographic images during a 15-year period (1993-2008) were reviewed at the Cincinnati Department of Veterans Affairs Medical Center. All patients underwent radiographic follow-up for at least 12 months (range 12-156, mean 45 ± 39.3 months), as well as clinical follow-up performed by neurosurgery staff for a mean of 29.3 ± 39.6 months (range 4-156 months). Clinical parameters at surgery and last examination included the Chiles modified Japanese Orthopaedic Association (mJOA) Myelopathy Scale. Measurements included cervical spine sagittal alignment on lateral radiographs preoperatively and postoperatively, focal Cobb angles at operated levels, and C2-7 regional alignment. Statistical analysis included the Student t-test and chi-square test. Perioperative complications and additional surgery in the cervical spine were recorded. The mJOA scores improved from a mean of 11.91 ± 2.4 preoperatively to 14.9 ± 2.33 postoperatively. The mean sagittal lordosis of the C2-7 spine increased from -16.2° ± 9.2° preoperatively to -18.5° ± 11.9° at last follow-up. Focal Cobb angles averaged a slight kyphotic angulation of 4.1° ± 2.3° at latest radiographic follow-up; of note, 7 patients (5.4%), all who had cylindrical titanium mesh cages (CTMCs), showed severe kyphotic angulation (+8.4° ± 2.4°). Patients with preoperative myelopathy showed clinical improvement at follow-up. The fusion rate was 96.2%; 3 of the 5 patients with radiographic evidence of nonfusion were smokers. Patients with postoperative kyphosis had significantly more chronic neck pain (visual analog scale score >4 lasting more than 6 months) and visits related to pain (p <0.01). Those with CTMCs had higher rates of postoperative kyphosis, chronic neck pain, and visits related to pain, irrespective of the number of levels fused (p <001). At latest follow-up, although a kyphotic increase occurred in the focal cervical sagittal Cobb angles, lordosis increased in C2-7 sagittal Gore angles. Two patients (1.5%) underwent revision of the implanted graft and/or hardware, and 5 patients (3.8%) had another procedure for adjacent-level pathologies 1-9 years later (mean 4.4 ± 2.7 years). Long-term follow-up data in our veteran population support cervical corpectomy as an effective, long-lasting treatment for spondylotic myelopathy of the cervical spine. Use of CTMCs without end caps was associated with statistically significant increased postoperative kyphotic angulation and chronic pain. Despite an increase in focal kyphosis over time, regional cervical sagittal lordotic alignment had increased at the latest follow-up. Further investigation will include the association of chronic neck pain and postoperative kyphosis, and high fusion rates among a veteran population of heavy smokers.

Cervical Laminectomy vs Laminoplasty: Is There a Difference in Outcome and Postoperative Pain?

Article

Oct 2011
NEUROSURGERY

Cervical laminoplasty is often used for the decompression of multilevel cervical spondylotic myelopathy without creating spinal instability and kyphosis. To assess the axial pain, quality of life, sagittal alignment, and extent of decompression after standard cervical laminectomy or laminoplasty. We further evaluate whether the sagittal alignment changes over time after both procedures and whether axial pain depends on sagittal alignment. We reviewed 268 patients with cervical radiculopathy or myelopathy who had undergone standard cervical laminectomy or laminoplasty between January 1999 and January 2009. The clinical outcome was analyzed by visual analog scale for neck pain. The quality of life was analyzed by EQ-5D questionnaire. The degree of deformity and extent of decompression were assessed using the Ishihara index and Pavlov's ratio, respectively. Laminoplasty was associated with more neck pain and worse quality of life when 4 or more levels were decompressed compared with the laminectomy group. For operations of 3 or fewer levels, there was no difference. Interestingly, the radiological effectiveness of decompression was greater in the laminoplasty group. Laminoplasty for 4 or more cervical levels was associated with more axial pain and consequently poorer quality of life than laminectomy. There was a similar loss of sagittal alignment in both the laminectomy and laminoplasty groups over time. Our results suggest there is no clear benefit of laminoplasty over laminectomy in patients who do not have spinal instability.

Safety and efficacy of rhBMP2 in posterior cervical spinal fusion for subaxial degenerative spine disease: Analysis of outcomes in 204 patients

Article

Aug 2011

Many studies offer excellent demonstration of the ability of bone morphogenic protein (BMP) to enhance fusion rates in anterior as well as posterior lumbar surgery. Recently, BMP has also been shown to increase arthrodesis rates in anterior cervical surgery, albeit with concomitant increases in complication rates. To date, however, few studies have investigated the safety and efficacy of BMP in cervical surgeries approached posteriorly. We retrospectively reviewed 204 consecutive patients with degenerative cervical spinal conditions necessitating posterior cervical fusion at a single institution over the past 4 years. The incidence of postoperative mechanical neck pain, fusion rates, as well as neurologic outcomes were compared between patients who received BMP vs those who did not receive BMP intraoperatively. There were no significant differences in preoperative variables between the non-BMP vs the BMP cohorts. Over an average follow-up of 24.2 months, there were no significant differences between the two cohorts in duration of hospitalization, cerebrospinal fluid leakage, deep vein thrombosis, pulmonary embolism, hyperostosis, infection, pneumonia, hematoma, C5 palsy, wound dehiscence, reoperation rates, or Nurick/ASIA scores. Eleven (7.1%) patients in the non-BMP group experienced instrumentation failure vs none in the BMP group (P=0.06). Patients receiving BMP had a significantly increased rate of fusion by the chi-square test (P=0.01) and the log-rank test (P=0.02). However, patients receiving BMP also had the highest rates of recurrent/persistent neck pain by the chi-square test (P=0.003) and the log-rank test (P=0.01). To date, few studies have evaluated the safety and efficacy of BMP in the posterior cervical spine. Here, we show that BMP usage does not increase complication rates, but it significantly increases arthrodesis rates and also may increase the rate of recurrent/persistent neck pain.

Anterior surgery in selective patients with massive ossification of posterior longitudinal ligament of cervical spine: Technical note

Article

Aug 2011
EUR SPINE J

The study includes case series, technical note and review of literature. The objective of this study was to assess the validity of the radiographic indicator and the result of anterior operation for massive ossification of posterior longitudinal ligament (MOPLL, ossification of posterior longitudinal ligament with an occupying ratio exceeding 50%). Anterior decompression yielded a better outcome than posterior approach in patients with MOPLL of cervical spine. But anterior surgery has the problem of technically demanding and was associated with a high incidence of surgery-related complications. Many ways for reducing the risk of anterior surgery have been reported, including floating method, employing microscopes or burrs, and laser-assisted corpectomy. A case series of selective patients with MOPLL of cervical spine undergoing anterior surgery is reported. All patients were strictly selected based on CT images with the appearance of open-base. 29 cases with more than 12 months follow-up (average, 31.0 ± 10.0 m) were reviewed. Average age at operation was 59.3 ± 8.2 years (43-73 years). Anterior decompression was done only for one or two vertebrae. One corpectomy was done in 13 cases, two corpectomies in 3 cases, and one corpectomy and one discectomy in 13 cases. Three levels were fused in 16 cases and two levels in 13 cases. No permanent neurological deterioration was observed. Neurological improvement was observed in every patients with an average improvement rate of 64 ± 23%. Mesh migration was observed in one case. A fusion rate of 100% was achieved. Anterior surgery using our technique may be a relatively simple and safe procedure in selective patients with massive ossification of posterior longitudinal ligament of cervical spine.

The Biomechanical Effect of Transverse Connectors Use in a Pre- and Postlaminectomy Model of the Posterior Cervical Spine

Article

Jun 2011
SPINE

An in vitro biomechanical study investigating the effect of transverse connectors on posterior cervical stabilization system in a laminectomy model. To evaluate the optimal design, number, and location of the transverse connectors in stabilizing long segment posterior instrumentation in the cervical spine. In the cervical spine, lateral mass screw (LMS) fixation is used for providing stability after decompression. Transverse connectors have been used to augment segmental posterior instrumentation. However, in the cervical region the optimal design, number, and the location of transverse connectors is not known. Seven fresh human cervicothoracic cadaveric spines (C2-T1) were tested by applying ±1.5 Nm moments in flexion (F), extension (E), lateral bending (LB), and axial rotation (AR). After testing the intact condition, LMS/rods were placed and then were tested with two different transverse connectors (top-loading connector [TL] and the head-to-head [HH] connector) in multiple levels, pre- and postlaminectomy (PL). LMS significantly reduced segmental motion by 77.2% in F, 75.6% in E, 86.6% in LB, and 86.1% in AR prelaminectomy and by 75.4% in F, 76% in E, 80.6% in LB, and 76.4% in AR postlaminectomy compared to intact (P < 0.05). Only in AR, PL constructs with HH connectors at C3 & C7, TL connectors at C4-C5 & C5-C6, and at C3-C4 & C6-C7 significantly reduced the range of motion by 12.9%, 11.9%, and 11.9%, respectively, compared to PL LMS (P < 0.05). No statistical significance was observed between TL connector and HH connector in all loading directions. The biomechanical advantage of transverse connectors is significant in AR, when using two connectors at the proximal and distal ends, compared to one connector. In a clinical setting, this data may guide surgeons on transverse connector configurations to consider during posterior cervical instrumentation.

Hemodynamic instability following carotid artery stenting

Article

Jun 2011
Neurosurg Focus

Postprocedural hypotension and bradycardia are important complications of carotid artery stenting (CAS) and are referred to as hemodynamic instability (HI). However, the incidence and impact of HI on the short-term prognosis of patients have been of a large debate. Twenty-seven patients were selected based on NASCET criteria, and they underwent CAS between September 2008 and September 2009. Continuous electrocardiography monitoring and supine blood pressure (BP) monitoring were performed before and after stent deployment and on the following day to detect HI, defined as systolic BP lower than 90 mm Hg or a heart rate lower than 60 bpm. Patients were asked to perform a Valsalva maneuver before and after stent deployment. The Valsalva ratios (VRs) along with other demographic and procedural data were documented and compared between patients with and without incidence of HI. Seventeen patients (63%) developed HI after CAS. The degree of stenosis was found to have a significant correlation with occurrence of HI (p < 0.006). No other risk factor or demographic data showed any correlation with HI. The VRs were significantly lower in the HI group compared with the non-HI group, indicating a significant autonomic dysfunction (p < 0.003). During follow-up, 1 patient (4.3%) developed major stroke, and the remaining patients were symptom free. Hemodynamic instability occurs frequently after CAS, but it seems to be a benign phenomenon and does not increase the risk of mortality or morbidity in the short term. A VR at rest less than 1.10, baseline autonomic dysfunction, and degree of carotid artery stenosis can be used as measures for predicting HI after CAS.

Efficacy of posterior cervical fusions utilizing an artificial bone graft expander, beta tricalcium phosphate

Article

Jan 2011

Nancy E Epstein

Several cervical laminectomies and instrumented posterior cervical fusions utilize iliac autograft supplemented with demineralized bone matrix, or bone morphogenetic protein, but few utilize artificial bone graft expanders. Here we analyzed whether posterior cervical fusions could effectively utilize iliac autograft supplemented with an artificial bone graft expander, Beta Tricalcium Phosphate [B-TCP] Fifty-three severely myelopathic patients [average Nurick Score 4.1], averaging 65.3 years of age, underwent posterior cervical laminectomies [average 2.3 levels] and multilevel instrumented fusions [average 7.5 levels] utilizing iliac crest autograft and B-TCP. Pathology addressed included multilevel spondylosis accompanied by ossification of the posterior longitudinal ligament [24 patients], ossification of the yellow ligament [27 patients], and instability [53 patients]. Fusion rates [dynamic X-ray, two-dimensional computerized axial tomography (2D-CT) and outcomes [Nurick Grades, Odom's Criteria, SF-36] were assessed at 3, 6, and 12 months postoperatively. Fusion was confirmed by two independent neuroradiologists utilizing dynamic X-ray studies [100% of patients] and 2D-CT studies [86.8% of patients] an average of 5.4 months postoperatively. Although there were no symptomatic pseudarthroses, three smokers exhibited delayed fusions [8 postoperative months]. Within 1 postoperative year, patients improved an average of 2.7 Nurick Grades [Nurick Score 1.4], Odom's criteria revealed 48 good/excellent, and 5 fair/poor outcomes, and improvement on all 8 SF-36 Health Scales [maximal on Bodily Pain [+21.96]. High fusion rates and improved neurological outcomes were achieved within one year for 53 patients undergoing multilevel level cervical laminectomies with posterior instrumented fusions utilizing iliac autograft supplemented with B-TCP.

Treatment of cervical stenotic myelopathy: A cost and outcome comparison of laminoplasty versus laminectomy and lateral mass fusion - Clinical article

Article

Feb 2011
J NEUROSURG-SPINE

Cervical stenotic myelopathy due to spondylosis or ossification of the posterior longitudinal ligament is often treated with laminoplasty or cervical laminectomy (with fusion). The goal of this study was to compare outcomes, radiographic results, complications, and implant costs associated with these 2 treatments. The authors analyzed the records of 56 patients (age range 42–81 years) who were surgically treated for cervical stenosis. Of this group, 30 underwent laminoplasty and 26 underwent laminectomy with fusion. Patients who had cervical kyphosis or spondylolisthesis were excluded. An average of 4 levels were instrumented in the laminoplasty group and 5 levels in the fusion group (p < 0.01). Forty-two percent of the fusions crossed the cervicothoracic junction, but no laminoplasty instrumentation crossed the cervicothoracic junction, and it only reached C-7 in one-third of the cases. Preoperative and postoperative Nurick grades and modified Japanese Orthopaedic Association (mJOA) scores were obtained. Outcomes were also assessed with neck pain visual analog scale (VAS) scores and the Odom outcome criteria. Postoperative length of stay, complications, and implant costs were calculated. The mean duration of follow-up, average patient age, and length of hospital stay were similar for both groups. The mean Nurick scores were also similar in the 2 groups and improved an average of 1.4 points in both (p < 0.01 for preoperative-postoperative comparison in each group). The mean mJOA scores improved 2.7 points in laminoplasty patients and 2.8 points in fusion patients (p < 0.01 for each group). The mean VAS scores for neck pain did not change significantly in the laminoplasty cohort (3.2 ± 2.8 [SD] preoperatively vs 3.4 ± 2.6 postoperatively, p = 0.50). In the fusion cohort, the mean VAS scores improved from 5.8 ± 3.2 to 3.0 ± 2.3 (p < 0.01). Excellent or good Odom outcomes were observed in 76.7% of the patients in the laminoplasty cohort and 80.8% of those in the fusion cohort (p = 0.71). In the fusion group, complications were twice as common and implant costs were nearly 3 times as high as in the laminoplasty group. When cases involving fusions crossing the cervicothoracic junction were excluded, analysis showed similar complication rates in the 2 groups. Patients treated with laminoplasty and patients treated with laminectomy and fusion had similar improvements in Nurick scores, mJOA scores, and Odom outcomes. Patients who underwent fusion typically had higher preoperative neck pain scores, but their neck pain improved significantly after surgery. There was no significant change in the neck pain scores of patients treated with laminoplasty. Our series suggests cervical fusion significantly reduces neck pain in patients with stenotic myelopathy, but that the cost of the implant and rate of reoperation are greater than in laminoplasty.

Article

Mar 2011
Neurosurg Focus

The surgical management of compressive cervical ossification of the posterior longitudinal ligament (OPLL) can be challenging. Traditionally, approach indications for decompression of cervical spondylotic myelopathy have been used. However, the postoperative complication profile after cervical OPLL decompression is unique and may require an alternative approach paradigm. The authors review the literature on approach-related OPLL complications and suggest a management strategy for patients with single- or multiple-segment OPLL with or without greater than 50% canal stenosis.

Spinal Cord Intramedullary Pressure in Cervical Kyphotic Deformity A Cadaveric Study

Article

Feb 2011
SPINE

In vitro cadaveric study of cervical spinal cord intramedullary pressure (IMP) in kyphotic deformity. To define the relationship between cervical spinal kyphotic deformity and spinal cord IMP. Previous studies of asymptomatic volunteers have revealed that the greatest variation in regional sagittal neutral upright spinal alignment occurs in the cervical spine with "normal" alignment ranging up to +15 to +20° kyphosis. We sought to determine whether IMP changes in response to increasing cervical kyphosis. In eight fresh-frozen cadavers, a progressive kyphotic deformity was created. Cadavers were positioned sitting with cervical lordosis, with head stabilized using a skull clamp. The C1 posterior arch was removed, dura was opened, and three pressure sensors were advanced caudally to C7, C4-C5, and C2 within the cord parenchyma. A stepwise kyphotic deformity was then induced by sequentially releasing and retightening the skull clamp while distracting posterior short segment rods and closing anterior segmental osteotomies. After each step, fluoroscopic images and pressure measurements were obtained. The C2-C7 Gore angle and horizontal displacement of the odontoid plumb line relative to C7 (C2-C7 sagittal vertical axis [SVA]) were measured. Minor IMP increases of 2 to 5 mm Hg were observed at one or more spinal cord levels in one of eight cadavers when the Gore angle was <+7.5° and in three of eight cadavers when the Gore angle was >+7.5° and <+21°. At Gore angles exceeding +21°, change in pressure (ΔIMP) progressively increased at one or more spinal cord levels in eight of eight cadavers. Gore angles ranging from +21° to +78° resulted in statistically significant increases in IMP ranging to >50 mm Hg, as did C2-C7 SVA >+75 mm. ΔIMP did not correlate with segmental spinal canal diameter (stenosis). Cervical lordosis and kyphosis less than +7.5° resulted in no meaningful increase in IMP. Minor cervical kyphosis measuring +7.5° to +21° resulted in 2 to 5 mm Hg increases in IMP. As the cervical kyphotic deformity exceeded +21°, IMP increased significantly. ΔIMP with spinal alignment may help to explain the wide range of "normal" cervical neutral upright sagittal alignment in studies of asymptomatic individuals and may help further define cervical kyphotic deformity.

Middle-Term Results of a Prospective Comparative Study of Anterior Decompression With Fusion and Posterior Decompression With Laminoplasty for the Treatment of Cervical Spondylotic Myelopathy

Article

Feb 2011
SPINE

A clinical prospective study. To assess whether clinical and radiologic outcomes differ between anterior decompression and fusion (ADF) and laminoplasty (LAMP) in the treatment of cervical spondylotic myelopathy (CSM). No reports to date have accurately and prospectively compared middle-term clinical outcomes after anterior and posterior decompression for CSM. We prospectively performed LAMP (n = 50) in 1996, 1998, 2000, and 2002, and ADF (n = 45) in 1997, 1999, 2001, and 2003. The Japanese Orthopedic Association (JOA) score, recovery rate, and each item of the JOA score were evaluated. For radiographic evaluation, the lordotic angle and range of motion (ROM) at C2-C7 and residual anterior compression to the spinal cord (ACS) after LAMP on magnetic resonance imaging were investigated. Eighty-six patients (ADF n = 39; LAMP n = 47) could be followed for more than 5 years (follow-up rate 91.5%). Demographics were similar between the two groups. The mean JOA score and recovery rate in the ADF group were superior to those in the LAMP group from 2-year data collected after surgery. However, LAMP was safer and less invasive than ADF with respect to physical status and complications in the perioperative period. For individual items of the JOA score, the ADF group showed significantly more improvement of upper extremity motor function than the LAMP group (P < 0.05). There was a significant difference in maintenance of the lordotic angle in the ADF group compared with the LAMP group despite no difference in ROM.The LAMP group was divided into two subgroups: (1) LAMP(+) (n = 16) comprising patients who had ACS at 2 years after surgery, and (2) LAMP(-) (n = 31) comprising patients without ACS. Recovery rate differed significantly between the LAMP(+) and LAMP(-) groups despite there being no difference between the LAMP(-) and ADF groups. The recovery rate of the JOA score in the ADF group was better than that in the LAMP group. The clinical outcomes after LAMP could be influenced by ACS.

Lateral Mass Screw Complications

Article

Dec 2010

Retrospective, consecutive patient series. To quantify the risks and the complications associated with screw fixation devices of the cervical spine. The usefulness of lateral mass internal fixation has been well documented in the clinical setting. However, there is a paucity of studies examining the complications associated with these devices in a degenerative clinical setting. From 1999 to 2007, 225 consecutive patients underwent posterior cervical fixation using a screw-plate and polyaxial screw-rod implant systems. There were 105 women and 120 men (age range: 45 to 84 y; mean, 68 y). In all patients, the surgical indication was cervical spondylosis with myelopathy. Mean follow-up interval was 18 months (range: 12 to 72 mo). Screw position was evaluated by computed tomography scanning postoperatively in all patients. Clinical and radiographic outcome was assessed at each visit after surgery. Intraoperative complications include fracture of lateral mass in 27 screws placement and nerve irritation in 3 bicortical screws. Early complications include hematoma formation in 2 cases and C5 root palsy in 5 cases after spinal canal decompression. Late complications include pseudarthrosis in 6 cases and screw pull-out in 3 cases. There were no cases of spinal cord or vertebral artery injury, infections, deaths, or adjacent segment disease. All patients had radiographic union, and no patient developed mechanical implant failure requiring removal of instrumentation. Reoperation was required in 14 (6.2%) cases because of nerve injury, hematoma formation, pseudarthrosis, and screw pull-out. Our clinical findings indicate that lateral mass fixation can be used safely with minimal complications and low rate of morbidity for cervical myelopathy treatment.

Intraoperative Electrophysiological Monitoring in Spine Surgery

Article

Dec 2010
SPINE

Review of the literature with analysis of pooled data. To assess common intraoperative neuromonitoring (IOM) changes that occur during the course of spinal surgery, potential causes of change, and determine appropriate responses. Further, there will be discussion of appropriate application of IOM, and medical legal aspects. The structured literature review will answer the following questions: What are the various IOM methods currently available for spinal surgery? What are the sensitivities and specificities of each modality for neural element injury? How are the changes in each modality best interpreted? What is the appropriate response to indicated changes? Recommendations will be made as to the interpretation and appropriate response to IOM changes. Total number of abstracts identified and reviewed was 187. Full review was performed on 18 articles. The MEDLINE database was queried using the search terms IOM, spinal surgery, SSEP, wake-up test, MEP, spontaneous and triggered electromyography alone and in various combinations. Abstracts were identified and reviewed. Individual case reports were excluded. Detailed information and data from appropriate articles were assessed and compiled. Ability to achieve IOM baseline data varied from 70% to 98% for somatosensory-evoked potentials (SSEP) and 66% to 100% for motor-evoked potentials (MEP) in absence of neural axis abnormality. Multimodality intraoperative neuromonitoring (MIOM) provided false negatives in 0% to 0.79% of cases, whereas isolated SSEP monitoring alone provided false negative in 0.063% to 2.7% of cases. MIOM provided false positive warning in 0.6% to 1.38% of cases. As spine surgery, and patient comorbidity, becomes increasingly complex, IOM permits more aggressive deformity correction and tumor resection. Combination of SSEP and MEP monitoring provides assessment of entire spinal cord functionality in real time. Spontaneous and triggered electromyography add assessment of nerve roots. The wake-up test can continue to serve as a supplement when needed. MIOM may prove useful in preservation of neurologic function where an alteration of approach is possible. IOM is a valuable tool for optimization of outcome in complex spinal surgery.

The Impact of Cervical Pedicle Screws for Primary Stability in Multilevel Posterior Cervical Stabilizations

Article

Oct 2010
SPINE

A total of 12 human cervical spines were tested in vitro in a biomechanical nondestructive set-up to compare the primary stability of different posterior cervical instrumentations after a bilevel corpectomy. To evaluate the primary 3-dimensional stability with special focus on the impact of cervical pedicle screws. Cervical pedicle screw fixation gains popularity due to supposed higher stability. However, biomechanical studies are rare. Especially the impact of a combination of lateral mass and pedicle screws on stability in multilevel posterior stabilizations has not been evaluated until now. A total of 12 human cervical specimens were loaded with pure moments and unconstrained motion between C4 and C7 was measured. The specimen were tested in the intact state, all lateral mass screws (all LMS) from C4-C7, cervical pedicle screws (CPS) C4 and C7 left, LMS C4-C7 right, C5+C6 left, CPS C4+C7 bilateral, LMS C5+C6, and a anterior-posterior instrumentation (360°). All instrumentations showed a higher stability compared with the intact state. No difference was found for uni- or bilateral applied CPS. The all LMS showed comparable stability than the CPS instrumentations. From a biomechanical primary stability point it seems unnecessary to add CPS in a bilevel corpectomy model. If CPS are added, the unilateral application seems sufficient.

Cervical laminectomy and instrumented lateral mass fusion: techniques, pearls and pitfalls

Abstract

No full-text available

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