ABSTRACT: The use of thoracic pedicle screws for the treatment of adolescent idiopathic scoliosis (AIS) has gained widespread popularity.
However, the placement of pedicle screws in the deformed spine poses unique challenges, and surgeons experience a learning
curve. The in vivo accuracy as determined by computed tomography (CT) of placement of thoracic pedicle screws in the deformed
spine as a function of surgeon experience is unknown. We undertook a retrospective review to determine the effect of surgeon
experience on the accuracy of thoracic pedicle screw placement in AIS. In 2005, we started to obtain routine postoperative
CT scans on patients undergoing a spinal fusion. From a database of these patients, we selected AIS patients, who underwent
a posterior spinal fusion. Fifteen consecutive patients for each of the following three groups stratified by attending surgeon
experience were selected (N=45): A) less than 20 cases of all pedicle screw constructs for AIS (surgeons <2years of practice), B) 20–50 cases (surgeons
2–5years of practice), and C) greater than 50 cases (surgeons greater than 5years of practice). Intraoperative evaluation
of all screws included probing of the pedicle screw tract, neurophysiologic monitoring, and fluoroscopic confirmation. A total
of 856 thoracic pedicle screws were studied. Postoperative CT scans were evaluated by two spine surgeons and a consensus read
established as follows: (1) In: intraosseous placement or ≤2-mm breach, (2) Out: >2-mm breach, either medial or lateral. Of
the 856 screws, 104 demonstrated a >2-mm breach, for an overall rate of 12.1% (medial=55, lateral=49, P=0.67). When the breach rates were stratified by surgeon experience, there was a trend toward decreased rate of breach for
the most experienced surgeons, although this did not attain statistical significance (Group A: 12.7%, Group B: 12.9%, Group
C: 10.8%, P=0.58). However, the most experienced group (C) had a markedly decreased rate of medial breaches (3.5 vs. 7.4% and 8.4%
for groups A and B, respectively, P<0.01). The breach rate for the concave periapical screws was not statistically different from the overall breach rate (13.0%
vs. 12.1%, P=0.93). In conclusion, the overall accuracy of placement of pedicle screws in the deformed spine was 87.9%, with no neurologic,
vascular, or visceral complications. Meticulous technique allows spine surgeons with a range of surgical experience to accurately
and safely place thoracic pedicle screws in the deformed spine. The most experienced surgeons demonstrated the lowest rate
of medial breaches.
European Spine Journal 04/2012; 19(1):91-95. · 1.97 Impact Factor
ABSTRACT: Reliable electromyography (EMG) thresholds for detecting medial breaches in the thoracic spine are lacking, and there is a paucity of reports evaluating this modality in patients with adolescent idiopathic scoliosis (AIS). This retrospective analysis evaluates the ability of triggered EMG to detect medial breaches with thoracic pedicle screws in patients with AIS. We reviewed 50 patients (937 pedicle screws) undergoing posterior spinal fusion (PSF) with intraoperative EMG testing. Postoperative CT scans were used for breach identification, and EMG values were analyzed. There were 47 medial breaches noted with a mean threshold stimulus of 10.2 mA (milliamperes). Only 8/47 breaches stimulated at 2-6 mA. Thirteen of the forty-seven screws tested at an EMG value ≤6 mA and/or a decrease of ≥65% compared with intraosseously placed screws. The sensitivity and positive predictive value for EMG was 0.28 and 0.21. A subanalysis of T10-T12 screws identified six of seven medial breaches. Using guidelines from the current literature, EMG does not appear to be reliable in detecting medial breaches from T2 to T9 but may have some utility from T10 to T12.
European Spine Journal 06/2011; 20(6):869-74. · 1.97 Impact Factor
ABSTRACT: A retrospective review of data prospectively entered into a multicenter database.
To evaluate the adherence to classification-specific surgical treatment recommendations for adolescent idiopathic scoliosis (AIS) before and after the Lenke classification system introduction in 2001.
The Lenke classification system of AIS was developed in 2001 to provide a comprehensive and reliable means to categorize and guide treatment. The treatment recommendations of the system state that major and structural minor curves are included in the instrumentation and fusion and the nonstructural minor curves are excluded.
Surgical AIS cases for each Lenke classification (curve types 1-6) were queried for "Rule-breakers," in which the treatment performed did not follow the recommendations of the Lenke classification system. Each "Rule-breaker" case was individually evaluated to ensure correct Lenke classification and radiographic image verification was performed. "Rule-breaker" patients were expressed as a percentage of the total number of patients for each curve type. The presence of "Rule-breakers" before and after the introduction of the Lenke classification system in 2001 was evaluated for statistical difference using a chi-square analysis.
The data for 1310 AIS patients who underwent surgical correction for their deformity were included in this analysis. Overall, treatment of 191 patients did not follow the classification recommendations; the rules are broken 15% of the time. The proportion of "Rule-breakers" (18%) was significantly greater prior to the introduction of the Lenke classification system than it was after (12%) (P=0.001).
The introduction of this system has led to a reduction in the variation of treatment approaches; however, our data suggest that 6% to 29% of the time, depending on the curve pattern, there are other aspects of the clinical and radiographic deformity that suggest deviation from the recommendations of the classification system. The outcome of adherence to this system remains yet to be evaluated.
Spine 02/2011; 36(14):1142-5. · 2.08 Impact Factor
ABSTRACT: Retrospective case review of skeletally immature patients treated with growing rods. Patients received an average of 9.6 years follow-up care.
(1) to identify the rate of autofusion in the growing spine with the use of growing rods; (2) to quantify how much correction can be attained with definitive instrumented fusion after long-term treatment with growing rods; and (3) to describe the extent of Smith-Petersen osteotomies required to gain correction of an autofused spine following growing rod treatment.
The safety and use of growing rods for curve correction and maintenance in the growing spine population has been established in published reports. While autofusion has been reported, the prevalence and sequelae are not known.
Nine skeletally immature children with scoliosis were identified who had been treated using growing rods. A retrospective review of the medical records and radiographs was conducted and the following data collected: complications, pre- and postoperative Cobb angles at time of initial surgery (growing rod placement), pre- and postoperative Cobb angles at time of final surgery (growing rod removal and definitive fusion), total spine length as measured from T1-S1, % correction since initiation of treatment and at definitive fusion, total number of surgeries, and number of patients found to have autofusion at the time of device removal.
The rate of autofusion in children treated with growing rods was 89%. The average percent of the Cobb angle correction obtained at definitive fusion was 44%. On average, 7 osteotomies per patient were required at the time of definitive fusion due to autofusion.
Although growing rods have efficacy in the control of deformity within the growing spine, they also have adverse effects on the spine. Immature spines treated with a growing rod have high rates of unintended autofusion which can possibly lead to difficult and only moderate correction at the time of definitive fusion.
Spine 10/2010; 35(22):E1199-203. · 2.08 Impact Factor
ABSTRACT: Tethering of the spinal cord is thought to increase the chance of neurological injury when scoliosis correction is undertaken. All patients with myelomeningocele (MM) are radiographically tethered, and untethering procedures carry significant morbidity risks including worsening neurological function and wound complications. No guidelines exist as regards untethering in patients with MM prior to scoliosis correction surgery. The authors' aim in this study was to evaluate their experience in patients with MM who were not untethered before scoliosis correction.
Seventeen patients with MM were retrospectively identified and 1) had no evidence of a clinically symptomatic tethered cord, 2) had undergone spinal fusion for scoliosis correction, and 3) had not been untethered for at least 1 year prior to surgery. The minimum follow-up after fusion was 2 years. Charts and radiographs were reviewed for neurological or shunt complications in the perioperative period.
The average age of the patients was 12.4 years, and the following neurological levels were affected: T-12 and above, 7 patients; L-1/L-2, 6 patients; L-3, 2 patients; and L-4, 2 patients. All were radiographically tethered as confirmed on MR imaging. Fourteen of the patients (82%) had a ventriculoperitoneal shunt. The mean Cobb angle was corrected from 82 degrees to 35 degrees , for a 57% correction. All patients underwent neuromonitoring of their upper extremities, and some underwent lower extremity monitoring as well. Postoperatively, no patient experienced a new cranial nerve palsy, shunt malfunction, change in urological function, or upper extremity weakness/sensory loss. One patient had transient lower extremity weakness, which returned to baseline within 1 month of surgery.
The study results suggested that spinal cord untethering may be unnecessary in patients with MM who are undergoing scoliosis corrective surgery and do not present with clinical symptoms of a tethered cord, even though tethering is radiographically demonstrated.
Neurosurgical FOCUS 07/2010; 29(1):E8. · 2.87 Impact Factor
ABSTRACT: Retrospective review.
To compare the incidence of and risk factors for proximal junctional kyphosis (PJK) in adolescent idiopathic scoliosis (AIS) following posterior spinal fusion using hook, pedicle screw, or hybrid constructs.
Proximal junctional kyphosis is a recently recognized phenomenon in adults and adolescents after AIS surgery. The postoperative effect on PJK with the use of hooks, hybrid constructs, or screws has not been compared in a multicenter study to date.
From a multicenter database, the preoperative and 2-year follow-up radiographic measurements from 283 patients with AIS treated with posterior spinal fusion using hooks (group 1, n = 51), hybrid constructs (group 2, n = 177), pedicle screws (group 3, n = 37), and pedicle screws with hooks only at the top level (group 4, n = 18) were compared.
The average proximal level kyphosis at 2 years after surgery was 8.2 degrees (range -1 to 18) in the all screw constructs, representing a significant increase when compared with hybrid and all hook constructs, 5.7 degrees (P = 0.02) and 5.0 degrees (P = 0.014), respectively. Conversely, average postoperative T5-T12 kyphosis was significantly less (P = 0.016) in the screw group compared with the all hook group. Of potential interest, but currently not statistically significant, was the trend towards a decrease in proximal kyphosis in constructs with all pedicle screws except hooks at the most cephalad segment, 6.4 degrees . The incidence of PJK (assuming PJK is a kyphotic deformity greater than 15 degrees ) was 0% in group 1, 2.3% in group 2, 8.1% in group 3, and 5.6% in group 4 (P = 0.18). Patients with PJK had an increased body mass index compared with those who did not meet criteria for PJK (P = 0.013).
Adjacent level proximal kyphosis was significantly increased with pedicle screws, but the clinical significance of this is unclear. A potential solution is the substitution of hooks at the upper-instrumented vertebrae, but further investigation is required.
Spine 01/2010; 35(2):177-81. · 2.08 Impact Factor
ABSTRACT: A multicenter prospective database was queried for patients who underwent open instrumented anterior spinal fusion (OASF) for treatment of primary thoracic (Lenke 1) adolescent idiopathic scoliosis (AIS).
To present the intermediate radiographic and pulmonary function testing (PFT) data from patients who underwent OASF using modern, rigid instrumentation.
Anterior spinal fusion is an excellent method to correct the 3-dimensional deformity produced by AIS. Modern instrumentation consisting of stronger metals, unthreaded rods, and dual rod systems should theoretically decrease the incidence of rod breakage, pseudarthrosis, and loss of correction seen in earlier OASF studies. The paucity of intermediate and long-term data prevents surgeons and patients from making an informed decision regarding the true incidence of these complications.
Of 101 potential patients who underwent OASF with a minimum 5-year follow-up, 85 (85%) were studied. Standing radiographs were analyzed before surgery and at first standing erect, 2-year, and 5-year follow-up. PFT data were collected before surgery and at 5 years after surgery.
Complete 5-year follow-up was obtained in 85 patients. Five years after surgery, the mean coronal correction was 26 degrees (51%; P < 0.05) and the thoracolumbar/lumbar curve improved 16 degrees (51%). There was a 9-degree (P < 0.001) increase in kyphosis, and there were 9 patients (11%) in whom the C7 plumb line translated >2 cm. There was a 6.7% decrease in predicted FEV1 over the 5-year period, from 75.5% +/- 13% before surgery to 68.8% +/- 2% at 5-year follow-up (P = 0.007); however, there was no significant change in FVC. There were 3 significant adverse events: 1 implant breakage requiring reoperation and 2 cases of progression of the main thoracic curve requiring reoperation.
OASF is a reproducible and safe method to treat thoracic AIS. It provides good coronal and sagittal correction of the main thoracic and compensatory thoracolumbar/lumbar curves that is maintained with intermediate term follow-up. In skeletally immature children, this technique can cause an increase in kyphosis beyond normal values, and less correction of kyphosis should be considered during instrumentation. As with any procedure that employs a thoracotomy, pulmonary function is mildly decreased at final follow-up.
Spine 01/2010; 35(1):64-70. · 2.08 Impact Factor
ABSTRACT: Clinical and radiologic assessment derived from a prospective multicenter data base of adolescent idiopathic scoliosis (AIS) patients.
We investigated if "implant density" or the number of screws correlated with the major curve (thoracic or lumbar) correction at 2 years in patients with AIS. We also investigated the effect of implant density on the change in sagittal contour before surgery to after surgery.
Controversy exists regarding number and type of spinal anchors and the number of implant sites used that result in improved correction in AIS.
A prospective database of patients with AIS treated by posterior instrumentation between 1995 and 2004 was analyzed. The major curve correction expressed as % correction (from preoperative to 2 years postoperative) was correlated with the percentage of implants relative to the number of available implant sites within the measured Cobb angle. Correlation of % correction to the number of hooks, wires, and screws was also performed. We also analyzed the change in sagittal contour T2-T12, T5-T12, and T10-L2 before surgery and after surgery. This absolute change was then correlated with implant density, as was the number of hooks, wires, and screws.
There were 292 patients included with all 6 Lenke curve types represented (250 with major thoracic curves and 42 with major lumbar curves). The overall % coronal Cobb correction was 64% (range: 11%-98%). The implant density within the major curve averaged 61% (range: 6%-100%). There was a significant correlation between implant density and % curve correction (r = 0.31, P < 0.001). The number of each implant type (hooks, wires, and screws) in the construct did not correlate with the % correction; however, the average % correction of the major curve was greater when the Cobb levels were instrumented only with screws (64%) compared to hooks alone (55%), P < 0.01. The greatest % correction 78% was achieved when bilateral segmental screws were used (100% screw density). The higher the implant density within the major thoracic curve, the greater the postoperative loss of kyphosis at T2-T12 (r = -0.13, P < 0.01) and T5-T12 (r = -0.16, P < 0.001). At T10-L2, increasing screw implant density correlated with decreasing kyphosis (r = -0.40, P < 0.001), whereas increasing hook implant density correlated with increasing kyphosis (r = 0.33, P < 0.001).
Major curve correction at 2 years correlates most with the implant density that is correction increases with the number of implants used within the measured Cobb levels. Although the absolute number of screws used did not correlate with correction, there was an advantage in lumbar and thoracic curves to using screws compared to hooks. Sagittal contour in the thoracic spine became less kyphotic than the higher the implant density.
Spine 09/2009; 34(20):2147-50. · 2.08 Impact Factor
ABSTRACT: Retrospective review with historical cohort.
Our study measures axial rotation of the apical vertebral bodies of patients with adolescent idiopathic scoliosis treated with an all pedicle screw (APS) construct versus a hook-rod (HR) construct using computed tomography (CT).
Ecker et al (Spine 1988;13:1141-4) observed a 22% derotation of the apical vertebrate of the thoracic spine and 33% of the apical vertebra of the lumbar spine when using an HR system (CD instrumentation). More recently Lee et al (Spine 2004;29:343-9) reported 42.5% derotation of the apical vertebra (both thoracic and lumbar) in a series of APS constructs. Currently, there is no comparison series reported between the 2 types of constructs.
From a database of 193 patients with adolescent idiopathic scoliosis and posterior spinal fusions, 32 patients were identified as having all APS constructs with pre- and postoperative CT scans. This cohort of patients was compared with a historical published cohort of patients treated with HR constructs by Ecker et al (Spine 1988;13:1141-4) Comparison of the groups showed no statistically significant differences for age and preoperative Cobb angle of the main curve (P > 0.05); however, there was a statistically significant difference (P < 0.05) in postoperative correction values. The apical vertebral rotation for the major curve was measured from the pre- and postoperative axial CT using the methods described by Aaro and Dahlborn (Spine 1981;6:460-7).
The average preoperative rotation was similar between the 2 groups (thoracic: HR = 22.6, APS = 21.3, P = 0.6; lumbar: HR = 19.4, APS = 20.6, P = 0.7). The postoperative correction had a significant difference (thoracic: HR = 16, APS = 8.5, P = 0.015; lumbar: HR = 13.4, APS = 7.0, P = 0.032). The percent correction of the apical vertebrae showed a significant difference, with 22% correction in the HR group and 60% in APS group (P < 0.001).
Our study finds axial rotation correction using APSs and a direct vertebral body derotation technique was significantly greater than that obtained with the HR construct.
Spine 04/2009; 34(8):804-7. · 2.08 Impact Factor
ABSTRACT: A multicenter study of changes in Scoliosis Research Society (SRS) outcome measures after surgical treatment of adolescent idiopathic scoliosis (AIS).
To evaluate changes in patient determined outcome measures between 2 and 5 years after AIS surgery.
Current surgical procedures have been shown to improve subjective measures in patients with AIS. At 2-year follow-up, AIS patients reported significant improvement in all 4 preoperative domains of the SRS questionnaire. In addition, the major Cobb angle was shown to be negatively correlated with preoperative scores in the pain, general self-image, and general function domains. Five-year SRS scores have not been evaluated previously.
A multicenter, prospectively generated database was used to obtain perioperative, radiographic, and SRS-24 outcomes data. The inclusion criteria were: a diagnosis of AIS, surgical treatment (anterior, posterior, or combined), a comprehensive set of radiographic measures, and completed preoperative, 2-year, and 5-year SRS questionnaires. Repeated measures analysis of variance was used to compare changes in patient responses for each of the 7 outcome domains. Univariate analysis of variance was used to compare the change in pain score at 5 years to the level of the lowest instrumented vertebrae and surgical approach. A correlation analysis was used to determine the association between changes in any of the radiographic variables and changes in SRS scores. The data were checked for normality and equal variances, and the level of significance was set at P < 0.01.
Forty-nine patients (42 women, 7 men; 14.2 +/- 2.1 year old; 5.4 +/- 0.6 years follow-up) met the inclusion criteria for this study. Thirty-seven of 49 (76%) of these patients underwent an open or thoracoscopic anterior procedure. SRS-24 scores improved significantly in 3 of the 4 preoperative domains at the 2-year visit. At 5 years postop, a statistically significant decrease in the pain score (4.2 +/- 0.6 to 3.9 +/- 0.9, P = 0.003) and a trend toward worsening scores in 4 other domains was observed; however, Patient Satisfaction scores remained unchanged. Lowest instrumented vertebrae and surgical approach could not be correlated to changes in the pain score. In addition, no correlation was found between changes in any of the 21 radiographic measures evaluated and changes in SRS scores.
There was a statistically significant increase in reported pain from 2 to 5 years after surgical treatment; however, the etiology of worsening pain scores could not be elucidated. Given continued patient satisfaction, the clinical relevance of this small reduction remains unknown. Nevertheless, this observation deserves further evaluation and must be considered in relation to the natural history of this disease.
Spine 06/2008; 33(10):1107-12. · 2.08 Impact Factor
ABSTRACT: Scoliosis is common in children with cerebral palsy. The incidence and curve pattern depend on the degree of neurologic involvement. These children carry a higher risk of complications because of the increased presence of associated medical comorbidities. Accordingly, a careful preoperative evaluation is required that should involve assessment of the patient's pulmonary, nutritional, gastrointestinal, and neurologic systems as well as a thorough evaluation of the spine and musculoskeletal system. Children with progressive curves >40 degrees to 50 degrees are candidates for spinal fusion, especially when the deformity interferes with sitting or is unresponsive to bracing. The goal of surgery is to obtain a stable, balanced, and painless spinal fusion. Although posterior spinal fusion with multisegmental fixation is the most common technique, others, such as anterior release and/or fusion or combined procedures, are now considered. In patients with significant pelvic obliquity or who are at risk of developing pelvic obliquity, instrumentation should extend to the pelvis, particularly in the nonambulatory child.
The Journal of the American Academy of Orthopaedic Surgeons 06/2006; 14(6):367-75. · 2.66 Impact Factor
ABSTRACT: A prospective, randomized study.
To compare the clinical results of posterior spinal fusion (PSF) with allograft augmentation versus no graft for patients with adolescent idiopathic scoliosis (AIS).
The use of allograft has become a standard means of augmenting a PSF. Many studies have shown equal rates of fusion when comparing allograft with autogenous iliac crest. There have been no studies to directly compare the results obtained with allograft with those achieved without the use of any bone graft at all.
Ninety-one patients with AIS were randomized into two treatment groups. Seventy-six patients had greater than 2-year follow-up and are included in this review. The Allograft Group consisted of 37 patients who underwent a standard PSF using a multisegmented hook-screw and rod system with the use of corticocancellous allograft for augmentation. The No Graft Group included 39 patients with AIS who underwent the same procedure without any bone graft. All autogenous bone resulting from a thoracoplasty and any local bone (for example, that removed from spinous processes) was discarded in both groups. Patients with at least 2 years of radiographic and clinical follow-up were evaluated using established criteria for possible or definite pseudarthrosis. Treatment groups were similar with respect to age, preoperative deformity, and correction obtained.
The overall definitive pseudarthrosis rate for this study was 1.3% (1 of 76 patients). The 1 patient with pseudarthrosis was in the Allograft Group (1 of 37, or 2.7%, P = 0.98 as defined by our criteria), versus none of 39 in the No Graft Group. Two patients in each group (5.4% in the Allograft Group and 5.1% in the No Graft Group) met the radiographic criteria for possible pseudarthrosis. This establishes a P value of 0.65 comparing risk of possible pseudarthrosis in the two groups.
Our results suggest that a PSF using newer-generation multisegmented hook-screw and rod systems can be successful with allograft and/or local bonegraft without the use of supplemental autogenous bone graft (from the iliac crest or ribs) in patients with AIS.
Spine 02/2006; 31(2):121-7. · 2.08 Impact Factor
ABSTRACT: The management of scoliosis in children has been evolving. Anterior release, diskectomy, and anterior instrumentation and spinal fusion (AISF) may be of benefit compared with a combined anterior and posterior or a posterior-only approach. Because thoracoscopic AISF (TAISF) has the potential benefit of muscle sparing, superior cosmesis, and less pain, the authors decided to prospectively compare this newer technique with open AISF (OAISF) to evaluate whether the 2 approaches were equivalent.
All children with idiopathic thoracic scoliosis undergoing AISF at a single center were prospectively examined. One hundred fifty-five children who had a minimum of 1-year follow-up were included in the study. Descriptive statistics are reported as means and SDs. Groups were compared using the independent-samples t test with Levene's test for equality of variances; a 2-tailed P value of .05 or less was considered significant.
Open AISF was performed in 114 patients and TAISF was performed in 41; there were 126 girls and 29 boys. Mean age at surgery was similar (14 +/- 3 vs 14.3 +/- 1.5 years; P = .5), as was weight (54.2 +/- 19 vs 54.6 +/- 23 kg; P = .9). There were no differences in preoperative thoracic curves (48.5 degrees +/- 14 degrees vs 49.8 degrees +/- 7 degrees; P = .6) or in the number of vertebral levels instrumented (7.7 +/- 1.3 vs 7.6 +/- 0.7; P = .7). Operative time was shorter with OAISF (383 +/- 65 vs 508 +/- 98 minutes; P < .01), and there was less estimated blood loss (924 +/- 724 vs 1218 +/- 747 mL; P = .03). The OAISF group took longer to extubate (1.4 +/- 1.2 vs 1 +/- 0.3 days; P = .03) and had slightly greater chest tube drainage (1710 +/- 730 vs 1639 +/- 515 mL; P = .5). At the 1-year follow-up, the thoracic curves were similar (17.5 degrees +/- 8 degrees vs 15.2 degrees +/- 7.5 degrees; P = .1) and percentage correction of thoracic curves was also similar (64% vs 69%).
Thoracoscopic AISF is safe and effective in correcting idiopathic childhood scoliosis. Correction of deformity with TAISF is equivalent to OAISF, although it takes longer and has more blood loss. However, it spares cutting muscle, uses smaller skin incisions, and appears to have superior cosmesis.
Journal of Pediatric Surgery 01/2005; 40(1):153-6; discussion 156-7. · 1.45 Impact Factor
ABSTRACT: Of new spinal cord injuries (SCIs) throughout North America, up to 14% occur in children younger than 15 years of age. The purpose of this paper is to present several aspects unique to the evaluation and treatment of a child with SCI.
Vital signs may be absent along with minimal blood loss, indicating upper cervical spine injury that is common in children. Lap belt injuries are more prevalent in children, especially since 1984, when seat belt laws were enacted, and more children began using a lap belt but no shoulder harness. Of children with lap belt injuries, 4% to 39% have significant neurologic injuries, and 30% to 50% have associated retroperitoneal injuries. Radiographic evaluation is more challenging in children because of the presence of normal variants such as C2-C3 pseudosubluxation, which occurs in 9% of children younger than 7 years. SCI without radiographic abnormality (SCIWORA) is common in children under 10 years of age and is associated with more complete neurologic injuries than in cases where the injuries can be seen on radiograph.
For transportation of children and infants younger than 6 years of age, the cervical spine needs to be in a neutral position, and spine boards need to be modified to allow for the larger head-to-torso ratio that is present in children. Cervical traction with Crutchfield tongs in children <12 years of age is associated with dural leaks, and therefore, the use of halo traction with modified pin placements is recommended. Indications for surgery are generally the same as those for adults in regard to decompression and alignment. The length of a spinal fusion for stabilization should be minimized in the thoracolumbar spine because of the potential for premature arrest of spinal growth.
The differences between children and adults with acute SCI are significant enough that caregivers cannot evaluate and treat a child with SCI as they would a small adult.
The journal of spinal cord medicine 02/2004; 27 Suppl 1:S11-5. · 2.11 Impact Factor
ABSTRACT: Before-after intervention study of a fusionless surgical technique to correct scoliosis secondary to spinal cord injury or myelodysplasia in children and adolescents.
To determine the feasibility, safety, and utility of a fusionless treatment option for paralytic scoliosis. Once determined, these data could then be applied to develop the application of this operation for patients with other types of scoliosis, such as idiopathic.
The optimal operative treatment for paralytic scoliosis remains to be determined. An ideal procedure would correct the deformity and stop the progression of scoliosis while maintaining mobility of the spine. This latter fact is important, especially for patients who rely heavily on use of trunk mobility for function.
Fourteen patients with scoliosis secondary to spinal cord injury or myelodysplasia underwent a fusionless vertebral body wedge osteotomy procedure. Feasibility was analyzed by the ability to correct the scoliosis with the osteotomies and preserve mobility. Safety was reported by estimated blood loss, neurologic stability, and complications. Utility was reported by radiographic evidence of arrested curve progression and maintenance of spinal mobility.
All 14 patients successfully underwent surgery to insert the wedge-rod system, with an average initial correction of 86% (range 66%-108%). The average estimated blood loss was 1050 cc (range 300-2000 cc). There were no major complications, and no changes in spasticity, bowel or bladder patterns, or motor/sensory levels. There was no case of nonunion at the osteotomy sites. At mean follow-up of 15 months (6-29 months), 10 patients had an improvement in their Cobb magnitude, 1 patient was within 5 degrees of their initial curve, 1 patient had a worse Cobb magnitude, and in 2 patients, the curve direction reversed but still measured less than the preoperative Cobb measurement. Spinal mobility was retained in all patients, as demonstrated on side-bending radiographs.
The vertebral wedge osteotomy procedure appears to be a potential option for the treatment of paralytic scoliosis. The procedure was feasible and safely performed in these 14 patients, with spinal mobility maintained. There were no nonunions. The efficacy of the procedure is still not known, as is for which patients the procedure is indicated and timing of the operation. Long-term follow-up (to skeletal maturity) is needed. Only six of the patients are currently skeletally mature, and more numbers are needed to determine efficacy in this group.
Spine 11/2003; 28(20):S266-74. · 2.08 Impact Factor
ABSTRACT: Study Design. A retrospective evaluation of 203 adolescent idiopathic scoliosis patients with Lenke 1B or 1C (King-Moe II) type curves.
Objectives. To evaluate the incidence of inclusion of the lumbar curve in the treatment of this type of deformity as well as radiographic factors associated with lumbar curve fusion.
Summary of Background Data. In patients with structural thoracic curves and compensatory lumbar curves, many authors have recommended fusing only the thoracic curve (selective thoracic fusion). Studies have shown that correction of the thoracic curve results in spontaneous correction of the unfused lumbar curve; however, in some cases, truncal decompensation develops. Though there have been various attempts to define more accurately what type of curve pattern should undergo selective fusion, controversy continues in this area.
Methods. Measurements were obtained from the preoperative standing posteroanterior and side-bending radiographs of 203 patients with Lenke Type 1B or 1C curves from five sites of the DePuy AcroMed Harms Study Group. Patients were divided into two groups depending on their most distal vertebra instrumented: the “selective thoracic fusion” group included patients who were fused to L1 or above and the “nonselective fusion” group included patients fused to L2 or below. A statistical comparison was conducted to identify variables associated with the choice for a nonselective fusion.
Results. The incidence of fusion of the lumbar curve ranged from 6% to 33% at the different patient care sites. Factors associated with nonselective fusion included larger preoperative lumbar curve magnitude (42 ± 10°vs. 37 ± 7°, P < 0.01), greater displacement of the lumbar apical vertebra from the central sacral vertical line, (3.1 ± 1.4 cm vs. 2.2 ± 0.8 cm, P < 0.01), and a smaller thoracic to lumbar curve magnitude ratio (1.31 ± 0.29 vs. 1.44 ± 0.30, P = 0.01).
Conclusions. The characteristics of the compensatory “nonstructural” lumbar curve played a significant role in the surgical decision-making process and varied substantially among members of the study group. Side-bending correction of the lumbar curve to <25° (defining these as Lenke 1, nonstructural lumbar curves) was not sufficientcriteria to perform a selective fusion in some of these cases. The substantial variation in the frequency of fusing the lumbar curve (6% to 33%) confirms that controversy remains about when surgeons feel the lumbar curve can be spared in Lenke 1B and 1C curves. Site-specific analysis revealed that the radiographic features significantly associated with a selective fusion varied according to the site at which the patient was treated. The rate of selective fusion was 92% for the 1B type curves compared to 68% for the 1C curves.
Since the 1950s, when Moe wrote his classic article defining curve patterns in adolescent idiopathic scoliosis (AIS) and their proposed treatment, controversy has continued over the treatment of the compensatory lumbar curve. Moe defined Type II curves as curves in which the nonstructural lumbar curve was smaller and more flexible than the thoracic curve. This type is distinct from the Type I, or double major curves, in which both the thoracic and lumbar curves are structural and therefore require fusion. In contrast, Moe suggested that the lumbar curve in a Type II curve pattern is compensatory and would undergo spontaneous correction with selective fusion of just the thoracic curve. 1,2
Subsequent studies that focused on the treatment of this Type II or “false double major” curve have had varying conclusions about fusing the lumbar curve. Some agree with Moe’s guidelines, whereas others have put forth limitations of curve magnitude, stating that a lumbar curve greater than 40° to 45° should be fused regardless of flexibility. 3–6 Lenke et al reported that the King-Moe definition of a Type II curve was not sufficient to recommend fusion of the thoracic curve alone and emphasized the relative differences of the thoracic and lumbar severity as guidelines in the decision to fuse the lumbar curve. They proposed that to fuse selectively in a false double major curve, the thoracic curve should be at least 20% bigger, have at least as much apical vertebral rotation, and have 20% more apical displacement than the minor lumbar curve. 7
The Lenke classification system is a more recently developed treatment-based classification that defines curve patterns by region, magnitude, and flexibility as well as sagittal profile and displacement of the lumbar apex from the central sacral vertical line. The system defines many of these false double major curves as Lenke Type 1B and 1C curves. In this curve pattern, the thoracic curve is the largest curve. The smaller lumbar curve is nonstructural (i.e., has a side-bending Cobb measurement of 25° or less) and has thoracolumbar kyphosis that is less than +20°. The system further classifies these curve patterns by the degree of apical displacement of the lumbar apex (A, B, or C) (Figure 1). 8–10
Spine 10/2003; 28(20S):S217-S223. · 2.08 Impact Factor
ABSTRACT: Retrospective review.
To report the feasibility, safety, and utility of vertebral body stapling without fusion as an alternative treatment for adolescent idiopathic scoliosis.
The success rate of brace treatment of adolescent idiopathic scoliosis ranges from 50% to 82%. However, poor self-image and brace compliance are issues for the patient. An alternative method of treatment such as a motion-preserving vertebral body stapling to provide curve stability would be desirable.
We retrospectively reviewed 21 patients (27 curves) with adolescent idiopathic scoliosis treated with vertebral body stapling. Patients were immature as defined by Risser sign <or=2.
The concept of vertebral body stapling of the convex side of a patient with adolescent idiopathic scoliosis is feasible. The procedure was safe, with no major complications and three minor complications. One patient had an intraoperative segmental vein bleed resulting in an increased estimated blood loss of 1500 cc as compared to the average estimated blood loss of 247 cc for all patients. One patient had a chylothorax and one pancreatitis. No patient has had a staple dislodge or move during the follow-up period (mean 11 months, range 3-36 months), and no adverse effects specifically from the staples have been identified. Utility (defined as curve stability) was evaluated in 10 patients with stapling with greater than 1-year follow-up (mean 22.6 months) and preoperative curve <50 degrees. Progression of >or=6 degrees or beyond 50 degrees was considered a failure of treatment. Of these 10 patients, 6 (60%) remained stable or improved and 4 (40%) progressed. One of 10 (10%) in the stapling group had progressed beyond 50 degrees and went on to fusion. Six patients required stapling of a second curve, three as part of the primary surgery, and three as a second stage, because a second untreated curve progressed. The results need to be considered with caution, as the follow-up is still short.
The data demonstrate that vertebral body stapling for the treatment of scoliosis in the adolescent was feasible and safe in this group of 21 patients. In the short-term, stapling appears to have utility in stabilizing curves of progressive adolescent idiopathic scoliosis.
Spine 10/2003; 28(20):S255-65. · 2.08 Impact Factor
ABSTRACT: A retrospective evaluation of 203 adolescent idiopathic scoliosis patients with Lenke 1B or 1C (King-Moe II) type curves.
To evaluate the incidence of inclusion of the lumbar curve in the treatment of this type of deformity as well as radiographic factors associated with lumbar curve fusion.
In patients with structural thoracic curves and compensatory lumbar curves, many authors have recommended fusing only the thoracic curve (selective thoracic fusion). Studies have shown that correction of the thoracic curve results in spontaneous correction of the unfused lumbar curve; however, in some cases, truncal decompensation develops. Though there have been various attempts to define more accurately what type of curve pattern should undergo selective fusion, controversy continues in this area.
Measurements were obtained from the preoperative standing posteroanterior and side-bending radiographs of 203 patients with Lenke Type 1B or 1C curves from five sites of the DePuy AcroMed Harms Study Group. Patients were divided into two groups depending on their most distal vertebra instrumented: the "selective thoracic fusion" group included patients who were fused to L1 or above and the "nonselective fusion" group included patients fused to L2 or below. A statistical comparison was conducted to identify variables associated with the choice for a nonselective fusion.
The incidence of fusion of the lumbar curve ranged from 6% to 33% at the different patient care sites. Factors associated with nonselective fusion included larger preoperative lumbar curve magnitude (42 +/- 10 degrees vs. 37 +/- 7 degrees, P < 0.01), greater displacement of the lumbar apical vertebra from the central sacral vertical line, (3.1 +/- 1.4 cm vs. 2.2 +/- 0.8 cm, P < 0.01), and a smaller thoracic to lumbar curve magnitude ratio (1.31 +/- 0.29 vs. 1.44 +/- 0.30, P = 0.01).
The characteristics of the compensatory "nonstructural" lumbar curve played a significant role in the surgical decision-making process and varied substantially among members of the study group. Side-bending correction of the lumbar curve to <25 degrees (defining these as Lenke 1, nonstructural lumbar curves) was not sufficientcriteria to perform a selective fusion in some of these cases. The substantial variation in the frequency of fusing the lumbar curve (6% to 33%) confirms that controversy remains about when surgeons feel the lumbar curve can be spared in Lenke 1B and 1C curves. Site-specific analysis revealed that the radiographic features significantly associated with a selective fusion varied according to the site at which the patient was treated. The rate of selective fusion was 92% for the 1B type curves compared to 68% for the 1C curves.
Spine 10/2003; 28(20):S217-23. · 2.08 Impact Factor
ABSTRACT: A multicenter study of the outcomes of the surgical treatment of adolescent idiopathic scoliosis using the Scoliosis Research Society Questionnaire (SRS 24).
To evaluate the patient based outcome of the surgical treatment of adolescent idiopathic scoliosis.
A paucity of information exists with respect to patient measures of outcome regarding the surgical treatment of adolescent idiopathic scoliosis. To our knowledge, no prospective outcome study on this topic thus far exists.
Using the SRS 24 questionnaire, seven scoliosis centers agreed to prospectively assess outcome for surgically treated patients with adolescent idiopathic scoliosis. Data were collected before surgery and at 24 months after surgery. Data were analyzed using paired and independent samples t test for all seven SRS 24 questionnaire domains (Pain, General Self-Image, Postoperative Self-Image, Postoperative Function, Function From Back Condition, General Level of Activity, and Satisfaction) using Statistical Package for Social Science. The domains were analyzed with respect to the total cohort, gender, curve magnitude, and type of surgery using independent-samples t tests.
A total of 242 patients were included in our analysis. A baseline preoperative pain level of 3.68 of 5 was found. This improved to 4.63 after surgery, representing an improvement of 0.95 points. Surgical intervention was associated with improving outcome when compared with preoperative status. Pain, General Self-Image, Function From Back Condition, and Level of Activity all demonstrated statistically significant improvement as compared with preoperative status (P < 0. 001). Overall, patients were highly satisfied with the results of surgery.
Preoperative pain exists in our adolescent scoliosis population. Pain scores were improved in our study population at the 2-year postsurgical follow-up. Statistically significant improvements were likewise seen in the General Self-Image, Function From Back Condition, and Level of Activity domains. The present study demonstrates the ability of surgery to improve the outcome of patients afflicted with adolescent idiopathic scoliosis.
Spine 09/2002; 27(18):2046-51. · 2.08 Impact Factor