Dino Samartzis

The University of Hong Kong, Hong Kong, Hong Kong

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Publications (87)345.59 Total impact

  • Article: Samartzis et al. respond.
    The spine journal: official journal of the North American Spine Society 03/2013; 13(3):226-8. · 2.90 Impact Factor
  • Article: Ionizing radiation exposure and the development of soft-tissue sarcomas in atomic-bomb survivors.
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    ABSTRACT: Very high levels of ionizing radiation exposure have been associated with the development of soft-tissue sarcoma. The effects of lower levels of ionizing radiation on sarcoma development are unknown. This study addressed the role of low to moderately high levels of ionizing radiation exposure in the development of soft-tissue sarcoma. Based on the Life Span Study cohort of Japanese atomic-bomb survivors, 80,180 individuals were prospectively assessed for the development of primary soft-tissue sarcoma. Colon dose in gray (Gy), the excess relative risk, and the excess absolute rate per Gy absorbed ionizing radiation dose were assessed. Subject demographic, age-specific, and survival parameters were evaluated. One hundred and four soft-tissue sarcomas were identified (mean colon dose = 0.18 Gy), associated with a 39% five-year survival rate. Mean ages at the time of the bombings and sarcoma diagnosis were 26.8 and 63.6 years, respectively. A linear dose-response model with an excess relative risk of 1.01 per Gy (95% confidence interval [CI]: 0.13 to 2.46; p = 0.019) and an excess absolute risk per Gy of 4.3 per 100,000 persons per year (95% CI: 1.1 to 8.9; p = 0.001) were noted in the development of soft-tissue sarcoma. This is one of the largest and longest studies (fifty-six years from the time of exposure to the time of follow-up) to assess ionizing radiation effects on the development of soft-tissue sarcoma. This is the first study to suggest that lower levels of ionizing radiation may be associated with the development of soft-tissue sarcoma, with exposure of 1 Gy doubling the risk of soft-tissue sarcoma development (linear dose-response). The five-year survival rate of patients with soft-tissue sarcoma in this population was much lower than that reported elsewhere. Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.
    The Journal of Bone and Joint Surgery 02/2013; 95(3):222-9. · 3.27 Impact Factor
  • Article: Immune cascades in human intervertebral disc: the pros and cons.
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    ABSTRACT: The unique structural hallmark of the intervertebral disc has made its central composition, the nucleus pulposus (NP), excluded from the immunologic tolerance. Consequently, the intervertebral disc is identified as an immune-privileged organ. Traditionally, local detrimental immune activities caused by NP at the lesion sites of the disc are noted as a significant factor contributing to disc degeneration. However, given the beneficial activities of immune cells in other immune-privileged sites on basis of current evidence, the degenerate disc might need the assistance of a subpopulation of immune cells to restore its structure and lessen inflammation. In addition, the beneficial impact of immune cells can be seen in the absorption of the herniated NP, which is an important factor causes the mechanical compression of nerve roots. Consequently, a modulated immune network in degenerate disc is essential for the restoration of this immune-privileged organ. Until now, the understandings of immune response in disc degeneration still rest on the harmful aspect. Further studies are needed to explore its beneficial influence. Accordingly, there are no absolutely the pros and cons in terms of immune reactions caused by NP.
    International journal of clinical and experimental pathology 01/2013; 6(6):1009-14. · 1.89 Impact Factor
  • Article: Magnetically controlled growing rods for scoliosis in children - Authors' reply.
    The Lancet 10/2012; 380(9849):1228-9. · 38.28 Impact Factor
  • Article: Reply to the letter by Alexiou and Voulgaris: "The influence of body mass index on lumbar disc degeneration"
    Arthritis & Rheumatism 08/2012; · 7.87 Impact Factor
  • Article: A New Variant of the Distractive‐Extension Injury of the Lower Cervical Spine: An Anatomic Cadaveric Sectioning, Radiographic, and Finite Element Analyses: Poster #81
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Spine Journal Meeting Abstracts. 08/2012;
  • Article: The predictive value of the fulcrum bending radiograph in spontaneous apical vertebral derotation in adolescent idiopathic scoliosis.
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    ABSTRACT: A prospective cohort study of Cobb angles (CA) and apical vertebral rotations (AVR) in 25 patients who had adolescent idiopathic scoliosis. To assess in vivo the concomitant vertebral derotation occurring with correction of scoliosis deformity as a result of coupling effect by using the fulcrum bending radiograph and to assess whether the fulcrum bending radiograph can predict the amount of postoperative apical derotation when no additional intraoperative apical derotation maneuver is used. Adolescent idiopathic scoliosis (AIS) is a 3-dimensional coupling deformity. Various studies have reported vertebral derotational effects, using different implant constructs and surgical techniques for AIS. However, none of them have considered the spontaneous coupling effect on vertebral derotation produced by correction of the coronal deformity, in particular, using the predictive capacity of the preoperative fulcrum bending radiograph. Twenty-five patients with flexible Lenke type 1 AIS with CA greater than 45° who underwent posterior spinal fusion with instrumentation, without direct apical derotation were prospectively assessed. CA and AVR in standing, supine, and fulcrum bending positions preoperatively and in supine position postoperatively were assessed on radiographs and computed tomographic scans. RESULTS.: The study entailed 80% adolescent girls and 20% adolescent boys (mean age, 15.5 years). The mean AVR values on preoperative standing, supine, and fulcrum bending positions and postoperation were 24.2°, 17.7°, 9.8°, and 8.1° respectively. The preoperative AVR highly correlated with the preoperative CA (R = 0.75). The postoperative AVR was correlated with the postoperative CA (r = 0.82) and the change in curve magnitude (r = -0.49), correction rate (r = -0.83), and fulcrum bending correction index (r = -0.45) (P < 0.05). There was no significant difference in AVR between preoperative fulcrum bending and postoperative assessment. Correction of scoliosis deformity produces spontaneous reduction of rotational deformity through coupling. The amount of spontaneous apical vertebral derotation with fulcrum bending can be used to assess the flexibility of the rotational deformity. In flexible curves, it also predicts the amount of apical derotation achievable with surgery. These should be considered when assessing the derotational effect of different implants and surgical strategies.
    Spine 07/2012; 37(15):E922-6. · 2.08 Impact Factor
  • Article: Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series.
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    ABSTRACT: Scoliosis in skeletally immature children is often treated by implantation of a rod to straighten the spine. Rods can be distracted (lengthened) as the spine grows, but patients need many invasive operations under general anaesthesia. Such operations are costly and associated with negative psychosocial outcomes. We assessed the effectiveness and safety of a new magnetically controlled growing rod (MCGR) for non-invasive outpatient distractions. We implanted the MCGR in five patients, two of whom have now reached 24 months' follow-up. Each patient underwent monthly outpatient distractions. We used radiography to measure the magnitude of the spinal curvature, rod distraction length, and spinal length. We assessed clinical outcome by measuring the degree of pain, function, mental health, satisfaction with treatment, and procedure-related complications. In the two patients with 24 months' follow-up, the mean degree of scoliosis, measured by Cobb angle, was 67° (SD 10°) before implantation and 29° (4°) at 24 months. Length of the instrumented segment of the spine increased by a mean of 1·9 mm (0·4 mm) with each distraction. Mean predicted versus actual rod distraction lengths were 2·3 mm (1·2 mm) versus 1·4 mm (0·7 mm) for patient 1, and 2·0 mm (0·2 mm) and 2·1 mm (0·7 mm) versus 1·9 mm (0·6 mm) and 1·7 mm (0·8 mm) for patient 2's right and left rods, respectively. Throughout follow-up, both patients had no pain, had good functional outcome, and were satisfied with the procedure. No MCGR-related complications were noted. The MCGR procedure can be safely and effectively used in outpatient settings, and minimises surgical scarring and psychological distress, improves quality of life, and is more cost-effective than is the traditional growing rod procedure. The technique could be used for non-invasive correction of abnormalities in other disorders. Ellipse Technologies.
    The Lancet 04/2012; 379(9830):1967-74. · 38.28 Impact Factor
  • Article: Are "patterns" of lumbar disc degeneration associated with low back pain?: new insights based on skipped level disc pathology.
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    ABSTRACT: A cross-sectional, population-based cohort study. The objective of this study was to evaluate the clinical relevance of skipped level disc degeneration (SLDD) to that of contiguous, multilevel disc degeneration (CMDD) of the lumbar spine. The study also aimed to identify patterns of SLDD, its classification, prevalence, and clinical relevance. The association of disc degeneration on magnetic resonance imaging with low back pain (LBP) remains questionable. The occurrence of SLDD of the lumbar spine has recently been noted. To date, patterns of disc degeneration have been overlooked in the association with low back symptoms. A population-based radiographic and clinical study of 3099 Southern Chinese patients. Individuals with multilevel disc degeneration of the lumbar spine on sagittal T2-weighted magnetic resonance imaging (N = 1457) were stratified to SLDD (n = 301; 20.7%) or CMDD (n = 1156; 79.3%) groups. SLDD was further classified into 5 types by the relative location of nondegenerated normal disc(s) to degenerated disc levels. Subject demographics, presence of LBP, pain intensity, and functional disability were assessed. In the multivariate analyses, CMDD increased the likelihood of historical LBP (odds ratio [OR]: 1.39; 95% confidence interval [CI]: 1.00-1.93; P = 0.047) and pain severity (OR: 1.83; 95% CI: 1.23-2.73; P = 0.003) in comparison with SLDD. A significant increasing trend of number of levels with disc degeneration, overall disc degeneration severity, and presence of disc bulges/extrusions was noted from SLDD type I (least severe) to SLDD type V (most severe) (P < 0.05). A higher prevalence of LBP and a higher pain intensity were observed in SLDD classification type V. Functional disability scores did not differ between CMDD and SLDD, nor within SLDD classification types (P > 0.05). Our large-scale study is the first to describe novel variants of SLDD types and their clinical relevance. More important, LBP and severity of pain were more pronounced in individuals with CMDD rather than those with SLDD. Our study suggests that subjects with a similar degree but different patterns of multilevel disc degeneration do differ with respect to low back symptoms. This finding may provide new evidence with regard to the mechanism of LBP.
    Spine 04/2012; 37(7):E430-8. · 2.08 Impact Factor
  • Article: Acute spinal subdural hematoma complicating lumbar decompressive surgery.
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    ABSTRACT: Study design: A case report.Objective: To report a rare case of acute spinal subdural hematoma (SSH) complicating lumbar spine surgery, its characteristic presenting symptoms, diagnostic imaging, possible cause, and pitfall in management.Methods: A 59-year-old woman with lumbar spinal instability and stenosis underwent laminectomy and decompression at L3-L5 with instrumentation and fusion from L3-S1.Results: Immediately following surgery, the patient presented with incapacitating pain of both lower extremities from the mid-thigh downward, which was not relieved by narcotic analgesia and was disproportional to surgical trauma. Left ankle and great toes weakness was detected at postoperative day 2 and deteriorated on day 6. Magnetic resonance imaging was performed urgently and revealed a characteristic SSH with thecal sac compression at the level of L2, proximal to the laminectomy. Emergency decompression and evacuation of the hematoma was performed. The patient had partial recovery 6 weeks postoperatively.Conclusion: Acute SSH is a rare complication of lumbar spine surgery. This diagnosis must be considered when severe leg pain, unresolved with analgesia and disproportional to surgical trauma, with neurological deterioration occurring after lumbar spine surgery. Magnetic resonance imaging is the imaging modality of choice to assist in the differential diagnosis of an SSH. Early surgical decompression is necessary for optimal neurological recovery.
    Evidence-based spine-care journal. 02/2012; 3(1):57-62.
  • Article: The association of lumbar intervertebral disc degeneration on magnetic resonance imaging with body mass index in overweight and obese adults: a population-based study.
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    ABSTRACT: To investigate the association of being overweight or obese with the presence, extent, and severity of lumbar disc degeneration on magnetic resonance imaging (MRI) in adults. A population-based cross-sectional study of 2,599 southern Chinese volunteers was conducted. Subjects underwent radiographic and clinical assessment, and weight and height were measured. Sagittal T2-weighted MRIs of the lumbar spine were obtained. The presence, extent, and severity of disc degeneration and additional radiographic and clinical parameters were assessed. Asian-modified body mass index (BMI) (kg/m(2) ) categories were used. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. The study included 1,040 men and 1,559 women (mean age 41.9 years). Disc degeneration was noted in 1,890 subjects (72.7%). BMI was significantly higher in subjects with disc degeneration (mean 23.3 kg/m(2) ) than in subjects without degeneration (mean 21.7 kg/m(2) ) (P < 0.001). A significant increase in the number of degenerated levels (P < 0.001), global severity of disc degeneration (P < 0.001), and end-stage disc degeneration with disc space narrowing (P < 0.001) was noted with elevated BMI, in particular in overweight and obese subjects. In the adjusted multivariate logistic regression model, there was a positive linear trend (r(2) = 0.99) between BMI and the overall presence of disc degeneration in overweight (OR 1.30 [95% CI 1.03-1.62]) and obese (OR 1.79 [95% CI 1.17-2.74]) subjects. End-stage disc degeneration with disc space narrowing was significantly more pronounced in obese subjects (adjusted OR 1.72 [95% CI 1.23-2.41] [reference normal weight]). Our findings, in one of the largest studies to systematically assess lumbar disc degeneration on MRI, indicated a significant association between the presence, extent, and global severity of disc degeneration with weight in overweight and obese adults.
    Arthritis & Rheumatism 01/2012; 64(5):1488-96. · 7.87 Impact Factor
  • Article: Genetic association studies in lumbar disc degeneration: a systematic review.
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    ABSTRACT: Low back pain is associated with lumbar disc degeneration, which is mainly due to genetic predisposition. The objective of this study was to perform a systematic review to evaluate genetic association studies in lumbar disc degeneration as defined on magnetic resonance imaging (MRI) in humans. A systematic literature search was conducted in MEDLINE, MEDLINE In-Process, SCOPUS, ISI Web of Science, The Genetic Association Database and The Human Genome Epidemiology Network for information published between 1990-2011 addressing genes and lumbar disc degeneration. Two investigators independently identified studies to determine inclusion, after which they performed data extraction and analysis. The level of cumulative genetic association evidence was analyzed according to The HuGENet Working Group guidelines. Fifty-two studies were included for review. Forty-eight studies reported at least one positive association between a genetic marker and lumbar disc degeneration. The phenotype definition of lumbar disc degeneration was highly variable between the studies and replications were inconsistent. Most of the associations presented with a weak level of evidence. The level of evidence was moderate for ASPN (D-repeat), COL11A1 (rs1676486), GDF5 (rs143383), SKT (rs16924573), THBS2 (rs9406328) and MMP9 (rs17576). Based on this first extensive systematic review on the topic, the credibility of reported genetic associations is mostly weak. Clear definition of lumbar disc degeneration phenotypes and large population-based cohorts are needed. An international consortium is needed to standardize genetic association studies in relation to disc degeneration.
    PLoS ONE 01/2012; 7(11):e49995. · 4.09 Impact Factor
  • Article: Age-related diffusion patterns in human lumbar intervertebral discs: a pilot study in asymptomatic subjects.
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    ABSTRACT: Diffusion tensor imaging (DTI) may provide an accurate noninvasive method of detecting degenerative matrix alterations in human lumbar intervertebral discs (IVDs). This study aimed to investigate age-related degenerative changes in human lumbar IVDs using DTI. Thirty asymptomatic volunteers ranging in age from 25 to 67 years underwent single-shot diffusion weighted echo-planar imaging on a 3 T scanner. DTI-derived metrics including fractional anisotropy (FA) and mean diffusivity (MD) were analyzed by a histogram analysis method. A Mann-Whitney test was used to compare subject groups (young and elderly) with respect to the diffusion measures, and piecewise linear regression was used to characterize the change in each metric as a function of age. We found significant age-related changes in the elderly adult group, with decrease of MD (11%, P<.001) and increase of FA (20%, P<.001). Our results demonstrate that the degenerative-related changes taking place in the IVDs through aging can be quantitatively accessed by DTI-derived metrics, while the morphologic changes are difficult to be identified in conventional T(2)-weighted images. Our initial findings suggest that it would be worthwhile to validate the relationship between DTI metrics and the actual degenerative status of IVDs using extracted disc samples and to extend it to studies on patients with degenerative discs in order to further explore the clinical usefulness and relevance of DTI.
    Magnetic Resonance Imaging 11/2011; 30(2):181-8. · 1.99 Impact Factor
  • Article: Structure and biology of the intervertebral disk in health and disease.
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    ABSTRACT: The intervertebral disks along the spine provide motion and protection against mechanical loading. The 3 structural components, nucleus pulposus, annulus fibrosus, and cartilage endplate, function as a synergistic unit, though each has its own role. The cells within each of these components have distinct origins in development and morphology, producing specific extracellular matrix proteins that are organized into unique architectures fit for intervertebral disk function. This article focuses on various aspects of intervertebral disk biology and disruptions that could lead to diseases such as intervertebral disk degeneration.
    Orthopedic Clinics of North America 10/2011; 42(4):447-64, vii. · 1.25 Impact Factor
  • Article: Genetics of lumbar disk degeneration: technology, study designs, and risk factors.
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    ABSTRACT: Lumbar disk degeneration (LDD) is a common musculoskeletal condition. Genetic risk factors have been suggested to play a major role in its cause. This article reviews the main research strategies that have been used to study the genetics of LDD, and the genes that thus far have been identified to influence susceptibility to LDD. With the rapid progress in genomic technologies, further advances in the genetics of LDD are expected in the next few years.
    Orthopedic Clinics of North America 10/2011; 42(4):479-86, vii. · 1.25 Impact Factor
  • Article: Management of degenerative disk disease and chronic low back pain.
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    ABSTRACT: Degenerative disk disease is a strong etiologic risk factor of chronic low back pain (LBP). A multidisciplinary approach to treatment is often warranted. Patient education, medication, and cognitive behavioral therapies are essential in the treatment of chronic LBP sufferers. Surgical intervention with a rehabilitation regime is sometimes advocated. Prognostic factors related to the outcome of different treatments include maladaptive pain coping and genetics. The identification of pain genes may assist in determining individuals susceptible to pain and in patient selection for appropriate therapy. Biologic therapies show promise, but clinical trials are needed before advocating their use in humans.
    Orthopedic Clinics of North America 10/2011; 42(4):513-28, viii. · 1.25 Impact Factor
  • Article: Lumbar intervertebral disk degeneration.
    Dino Samartzis, Kenneth M C Cheung
    Orthopedic Clinics of North America 10/2011; 42(4):xi-xii. · 1.25 Impact Factor
  • Article: Degenerative magnetic resonance imaging changes in patients with chronic low back pain: a systematic review.
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    ABSTRACT: Systematic review. To systematically search for critically appraise and summarize studies that (1) evaluated the association between degenerative magnetic resonance imaging (MRI) changes and chronic low back pain (CLBP) and (2) compared surgical and nonsurgical treatment of these degenerative MRI changes. The role of routine MRI in patients with CLBP is unclear. It is also uncertain whether or not surgical treatment of degenerative MRI changes results in alleviation of back pain. Systematic literature searches were conducted in PubMed for studies published through March 1, 2011. To evaluate whether MRI degenerative changes are associated with CLBP, studies that were designed to compare the prevalence of MRI changes among subjects with and without CLBP were sought. The prevalence odds ratio was used to compare the odds of degenerative MRI findings in subjects with CLBP to the odds of such findings among those without CLBP. To evaluate whether surgical treatment of degenerative MRI changes is associated with different outcomes compared with nonsurgical treatment, comparative studies were sought. The GRADE system as applied to describe the strength of the overall body of evidence. Regarding the association of degenerative changes on MRI and CLBP, five studies were included, all of which were cross-sectional in design. On the basis of these studies, a statistically significant association was found in all but one study regarding the presence of disc degeneration and CLBP (odds ratio range: 1.8-2.8). The overall strength of evidence across studies was considered to be insufficient, however. No comparative studies of surgical versus nonsurgical treatment of degenerative MRI changes were identified. Although there may be an association between degenerative MRI changes and CLBP, it is unknown if these estimates accurately represent the association given the quality of included studies, lack of a direct link between degenerative MRI changes and CLBP, and heterogeneity across studies. Thus, a strong recommendation against the routine use of MRI for CLBP evaluation is made. Since there are no data evaluating the efficacy of the surgical treatment of degenerative MRI changes, a strong recommendation is made against the surgical treatment of CLBP based solely upon degenerative MRI changes. Recommendation 1: There is insuffi cient evidence to support the routine use of MRI in patients with CLBP. Recommendation: Strong Recommendation 2: Surgical treatment of CLBP based exclusively on MRI fi ndings of degenerative changes is not recommended. Recommendation: Strong.
    Spine 10/2011; 36(21 Suppl):S43-53. · 2.08 Impact Factor
  • Article: Cervical scoliosis in the Klippel-Feil patient.
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    ABSTRACT: Retrospective study. This study addressed in patients with Klippel-Feil syndrome (KFS), the role of congenitally fused cervical patterns, risk factors, and cervical symptoms associated with cervical scoliosis. KFS is an uncommon condition, characterized as improper segmentation of one or more cervical spine segments with or without associated spinal or extraspinal manifestations. "Scoliosis" is potentially the most common manifestation associated with KFS. However, the role of congenitally fused cervical patterns along with additional potential risk factors and their association with cervical scoliosis, and its relationship with cervical spine-related symptoms remain largely unknown. Plain radiographs were utilized to assess the location of congenitally fused cervical segments (O-T1), degree of coronal cervical alignment, and any additional cervical and thoracic spine abnormalities. The classification scheme, as proposed by Samartzis et al of congenitally fused cervical patterns (Types I-III) in KFS patients, was utilized and additional fusion and region-specific patterns were assessed. Patients with coronal cervical alignments of 10° or greater were regarded scoliotic. Patient demographics and the presence of cervical spine-related symptoms were also assessed. Thirty KFS patients were assessed (mean age, 13.5 yr). The mean coronal cervical alignment was 18.7° and scoliosis was noted in 16 patients. Patients that exhibited congenital fusion of the mid and lower cervical spine region, had multiple, contiguous congenitally fused segments (Type III), and associated vertebral malformations (e.g., hemivertebrae) were highly associated with the presence of cervical scoliosis (P < 0.05). Ten patients exhibited cervical spine-related symptoms; however, no statistically significant difference was noted between the presence of symptoms and coronal cervical alignment (P = 0.815) and cervical scoliosis (P = 0.450). The study noted a prevalence of cervical scoliosis to occur in 53.3% of young KFS patients. Such patients that exhibited congenital fusion of the mid and lower cervical spine region, had multiple, contiguous congenitally fused segments (Type III), and associated vertebral malformations (e.g., hemivertebrae) were highly associated with the presence of cervical scoliosis. However, in young KFS patients, the presence of cervical scoliosis may not be associated with the manifestation of cervical spine-related symptoms.
    Spine 09/2011; 36(23):E1501-8. · 2.08 Impact Factor
  • Article: "Spring-back" closure associated with open-door cervical laminoplasty.
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    ABSTRACT: Spring-back complication after open-door laminoplasty as described by Hirabayashi is a well-known risk, but its definition, incidence, and associated neurologic outcome remain unclear. To investigate the incidence and the neurologic consequence of spring-back closure after open-door laminoplasty. A retrospective radiographic and clinical review. Lateral cervical spine X-rays were evaluated. Anteroposterior diameters (APD) of the vertebral canal of C3-C7 were measured. Spring-back was defined as loss of APD on follow-up in comparison to immediate postoperative canal expansion. The loss of the end-on lamina silhouette with consequent reappearance of the lateral profile of the spinous processes was also assessed to verify the presence of spring-back. Spring-back closure was classified based on whether the collapse was total or partial, and whether all the operated levels or only a subset had collapsed (ie, complete vs. partial closure, segmental closure vs. total-construct closure). Neurologic status was documented using the Japanese Orthopaedic Association (JOA) score. Thirty consecutive patients who underwent open-door laminoplasty from 1995 to 2005 at a single institution with a minimum follow-up of 2 years were assessed. They were all operated on using the classic Hirabayashi technique. Radiographic outcomes were assessed independently by two individuals. Sixteen men and 14 women with an average follow-up of 5 years (range, 2-12 years) were included. Of these patients, 24 had cervical spondylotic myelopathy and six had ossification of the posterior longitudinal ligament. Spring-back closure was found in three patients (10%) and 7 of 117 laminae (6%) within 6 months of the operation, which was further confirmed by computed tomography and magnetic resonance imaging. All spring-back closures were partial segmental closures. Gender and age were not significant factors related to spring back (p>.05). The mean JOA score on follow-up was 12.5, with a recovery rate of 40%. All patients with spring back and available JOA data exhibited postoperative neurologic deterioration. Of the three patients with spring back, two patients underwent revision surgery, whereas one declined. Spring-back closure occurred in 10% of our patients at or before 6 months after surgery. The incidence of spring-back by level (ie, 117 laminae) was 6%, mainly occurring at the lower cervical spine. All spring-back closures were partial segmental closures, most commonly involving C5 and C6. Postoperative neurologic deficit was associated with spring-back closure; therefore, surgeons should adopt preemptive surgical measures to prevent the occurrence of such a complication.
    The spine journal: official journal of the North American Spine Society 09/2011; 11(9):832-8. · 2.90 Impact Factor

Institutions

  • 2010–2013
    • The University of Hong Kong
      • Department of Orthopaedics and Traumatology
      Hong Kong, Hong Kong
  • 2011
    • University of Oulu
      • Department of Physical Medicine and Rehabilitation
      Oulu, Oulu, Finland
    • Fourth Military Medical University
      Xi’an, Liaoning, China
  • 2008–2011
    • Shriners Hospitals for Children
      Tampa, FL, USA
    • Erasmus Universiteit Rotterdam
      • Department of Orthopaedics
      Rotterdam, South Holland, Netherlands
    • Rush University Medical Center
      • Department of Orthopaedic Surgery
      Chicago, IL, USA
  • 2007–2011
    • Radiation Effects Research Foundation
      Hiroshima-shi, Hiroshima-ken, Japan
  • 2005–2009
    • University of Virginia
      • Department of Orthopaedic Surgery
      Charlottesville, VA, USA
  • 2005–2008
    • Harvard University
      Boston, MA, USA
  • 2006
    • University of Oxford
      Oxford, ENG, United Kingdom