Ensor E. Transfeldt

The effects of immobilization of long segments of the spine on the adjacent and distal facet force and lumbosacral motion

Long levels of spinal instrumentation and fusion are common in surgery for spinal deformity. The effect on the remaining mobile segments is not well understood. The changes in lumbar facet loading and lumbosacral motion were evaluated as the number of immobilized levels increased. Four fresh canine cadaveric spines from T6 to sacrum were used. Lumbosacral motion was measured with an instrumented spatial linkage device, and facet loads were measured at L1, L4, and L7 using a strain gauge technique. Lumbosacral motion and facet loading were significantly increased (P < 0.05) after immobilization of proximal segments, and the amount of the increase was dependent on the number of immobilized segments (P < 0.05). This indicates that immobilization of long segments of the spine influences the remaining mobile segments by increasing the load and motion not only at the immediately adjacent segment but also at the distal segments.

Spondylolisthesis, Pelvic Incidence, and Spinopelvic Balance : A Correlation Study

Study Design. A retrospective study of the sagittal alignment in developmental spondylolisthesis. Objectives. To investigate the role of pelvic anatomy and its effect on the global balance of the trunk in developmental spondylolisthesis. Summary of Background Data. Pelvic incidence (PI) is a fundamental anatomic parameter that is specific and constant for each individual, and independent of the three-dimensional orientation of the pelvis. Recent studies have suggested an association between a high PI and patients with isthmic spondylolisthesis. Methods. The lateral standing radiographs of the spine and pelvis of 214 subjects with developmental L5–S1 spondylolisthesis were analyzed with a dedicated software allowing the calculation of the following parameters: pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and grade of spondylolisthesis. All measurements were done by the same individual and compared to those of a cohort of 160 normal subjects. Student’s tests were used to compare the parameters between the curve types and Pearson’s correlation coefficients were used to investigate the association between all parameters (&agr; = 0.01). Results. PI, SS, PT, and LL are significantly greater (P < 0.01) in subjects with spondylolisthesis, while TK is significantly decreased. PI has a direct linear correlation (0.41–0.65) with SS, PT, and LL. Furthermore, the differences between the two populations increase in a direct linear fashion as the severity of the spondylolisthesis increases. Conclusions. Since PI is a constant anatomic pelvic variable specific to each individual and strongly determines SS, PT, and LL, which are position-dependent variables, this study suggests that pelvic anatomy has a direct influence on the development of a spondylolisthesis. Study participants with an increased pelvic incidence appear to be at higher risk of presenting a spondylolisthesis, and an increased PI may be an important factor predisposing to progression in developmental spondylolisthesis.

Lumbosacral chordoma. Prognostic factors and treatment.

STUDY DESIGN Retrospective analysis. OBJECTIVES To analyze the prognostic factors in patients with chordomas, the success of various treatments, the diagnostic value of open versus needle biopsy, the neurologic impairment after sacral nerve resection, and the clinical presentation and site of origin. SUMMARY OF BACKGROUND DATA Staging of chordomas has not been of much value, compared with other bone tumors, because for chordomas, grade is similar, metastasis is infrequent at presentation, and the prognostic significance of size is uncertain. METHODS A review of patients with chordoma from 1965 through 1996 found 23 cases (mean age of patients, 55 years). The mean follow-up was 84 months. Mean tumor size was 81 mm (range, 35-135 mm), location was lumbar (n = 6), S1 (n = 4), S2 (n = 3), S3 (n = 7), S4 (n = 2), and S5 (n = 1). RESULTS No tumors were found in the higher sacrum (S1-S2) alone, without involvement of the lower sacrum. Survival analysis at 5 years showed overall survival (OS) 86%, continuous disease-free survival (CDFS) 58%, and local recurrence-free survival (LRFS) 60%. The location of tumor, defined by highest level of involvement (lumbar vs. sacrum) was of prognostic significance for OS (P = 0.01; log-rank test), CDFS (P = 0.036), but not for LRFS (P = 0.189). Results of multivariate regression showed that location was significant for OS (P = 0.007), CDFS (P = 0.008), and LRFS (P = 0.001). For patients with positive margins (n = 16), initial radiation correlated with longer CDFS (P = 0.002; Mantel-Cox) and LRFS (P = 0.005, Mantel-Cox), but was not significant for OS (P = 0.41). For patients who received no radiation, a positive margin correlated with a shorter CDFS (P = 0.04), a trend to shorter LRFS (P = 0.08), but no difference in OS. Therefore, both a tumor-free margin and initial radiation correlated with a longer survival. No patients had urinary or bowel dysfunction when both S3 nerves were preserved. If one S3 nerve was preserved, 1 of 3 patients had partial urinary incontinence and 2 of 3 patients required bowel medications. If both S3 nerves were resected, all patients required intermittent urinary catheterization and bowel medications. If both S2 nerves were resected, there was complete urinary and bowel incontinence. CONCLUSIONS The highest level of tumor involvement was prognostically significant for OS, CDFS, and LRFS. Radiation was of value when complete excision was not achieved. Bilateral S3 nerve preservation is necessary to ensure retention of normal urinary and bowel function.

Decompensation After Cotrel-dubousset Instrumentation of Idiopathic Scoliosis

Spinal decompensation after corrective surgery for scoliosis appears to be a significant problem after Cotrel-Dubousset instrumentation (CDI). CDI produces torsional changes in the instrumented and uninstrumented spine that could result in spinal imbalance. Preoperative and postoperative three-dimensional analysis including computed tomography (CT) scans to measure vertebral rotation and segmental rotation were performed to evaluate the importance of torsional changes. Moe/King Type II deformities had a substantially greater risk of imbalance. Deformities instrumented over fewer spinal segments were less likely to decompensate. Specifically, instrumentation excluding the mobile transition segment, determined by maximum segmental rotation and segmental Cobb angle, was likely to decompensate. Derotation and deformity correction excessive in relation to preoperative side bending flexibility and segmental rotation frequently resulted in imbalance. Spinal imbalance after CDI can be reduced by avoiding overcorrection and inclusion of mobile transition segments.

Does scoliosis have a psychological impact and does gender make a difference

Study Design. A population-based case-control study, we identified adolescents with and without scoliosis in Minnesota who were 12 through 18 years of age. Matched control subjects were randomly selected from school children who did not have scoliosis or any other condition. Information on scoliosis was obtained by a self-administered questionnaire, the Adolescent Health Survey. Collected on more than 75,000 school age adolescents, with established validity and reliability, a secondary analysis of adolescents with scoliosis was performed as compared with a normative peer group. Objective. To describe and characterize the psychosocial impact of scoliosis on the areas of peer relations, body image, and health-compromising behavior, such as suicidal thought and alcohol consumption. Summary of Background Data. The impact of adolescent idiopathic scoliosis has not been assessed using generic health status measures appropriate for adolescents. Previous studies have concentrated on the health status of adults by measuring work status, marriage status, and other adult measures. The purpose of this study was to study the health status of patients with adolescent idiopathic scoliosis, using the Adolescent Health Survey, a generic health status measure with established validity and reliability. Methods. Body image, peer relations, social and high-risk behavior, and comparative health were assessed to determine if scoliosis was an independent risk factor and to determine if scoliosis was associated with these psychosocial issues. Results. Six hundred eighty-five cases of scoliosis were identified from the 34,706 adolescents. The prevalence was 1.97%. Of the 685 adolescents with scoliosis and their control subjects, the adjusted odds ratio for having suicidal thought among adolescents with scoliosis, compared to adolescents without scoliosis, was 1.40 (P value of 0.04) after adjustment for race, gender, socioeconomic status, and age. The adjusted odds ratio for having feelings about poor body development among adolescents with scoliosis was 1.82 (P value 0.001) compared with adolescents without scoliosis after adjustment for race, gender, socioeconomic status, and age. Scoliosis was an independent risk factor for suicidal thought, worry and concern over body development, and peer interactions after adjustment. Conclusion. Scoliosis is a significant risk factor for psychosocial issues and health-compromising behavior. Gender differences exist in male and female adolescents with scoliosis.

Can c7 plumbline and gravity line predict health related quality of life in adult scoliosis

Study Design. This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presenting with scoliosis at a single institution, as related to their spinal (C7 plumbline) and global (gravity line) balance. Objective. To assess the influence of sagittal and coronal balance on HRQOL in adult scoliosis. Summary of Background Data. Many surgeons believe that achieving adequate spinal balance is important in the management of adult spinal deformity, but the evidence supporting this concept remains limited. A previous study has found weak correlations between sagittal spinal balance and HRQOL in adult spinal deformity, but this finding has never been confirmed independently. In addition, although the use of the gravity line is gaining interest in the evaluation of global balance, it remains unknown if this parameter is associated with HRQOL. Methods. During a 1-year period, 73 consecutive new patients presenting with unoperated adult scoliosis and requiring full spine standing radiographs were evaluated using a force plate in order to simultaneously assess the gravity line. All patients also completed the Oswestry Disability Index (ODI) questionnaire to assess the HRQOL. Spinal balance was evaluated from the C7 plumbline and global balance from the gravity line, respectively. C7 plumbline and gravity line were both assessed with respect to the posterosuperior corner of the S1 vertebral body and central sacral vertebral line in the sagittal and coronal plane, respectively. C7 plumbline and gravity line, as well as their relative position, were correlated with the ODI, using Spearman coefficients. Results. Sagittal spinal (C7 plumbline) and global (gravity line) balance, as well as their relative position were significantly related to the ODI. A poor ODI (>34) was associated with a sagittal C7 plumbline greater than 6 cm, a sagittal gravity line greater than 6 cm, and a C7 plumbline in front of the gravity line. Correlations between coronal balance and the ODI were not statistically significant. Conclusion. Sagittal spinal and global balance was strongly related to the ODI in adults with scoliosis. The observed correlation coefficients were higher than those reported in the only previous study suggesting the detrimental association of positive sagittal balance on ODI in adult spinal deformity. Coronal spinal and global balance did not influence the ODI in the current study cohort. Thisstudy underlines the relevance of C7 plumbline and gravity line in the evaluation of spinal and global balance, and lends further support to the philosophy of achieving adequate sagittal balance in the management of adult spinal deformity, especially in patients older than 50 years old with degenerative scoliosis.

Reduction of high-grade spondylolisthesis using Edwards instrumentation

Study Design Sixteen patients with high-grade spondylolisthesis (Grade III or higher) who underwent posterior decompression and reduction using the Edwards Modular Spine System (Spinal System Ltd., Baltimore, MD) were reviewed clinically and radiographically. Objectives This study was undertaken to determine the efficacy of one specific reduction technique to treat patients with high-grade spondylolisthesis where there has been a loss of sagittal balance, intractable pain, and/or neurologic deficit. Summary of Background Data The average age of our patients was 20 years. Preoperative slippage averaged 89%; preoperative slip angle averaged 50°. Indications for surgery were back and leg pain, progression of slippage (in 9 patients), and/or the inability to stand upright with the knees straight. Methods Pre- and postoperative radiographic films were reviewed. The percent slip and the slip angle were measured pre- and postoperatively. Clinical data were obtained via chart review, telephone interview, and/or office visit. Results The average preoperative slip was 89%; postoperatively, the average slip was 29%. Slip angle averaged 50° preoperatively and improved to a postoperative average of 24°. Three patients had neurologic impairment postoperatively; one did not resolve. Four patients had hardware failure; all were revised. Ten patients had an excellent result, 5 patients had a good result, and 1 patient had a fair result. The average follow-up was 3.8 years. Conclusion This procedure is technically demanding and is subject to the known risks of surgical treatment for high-grade spondylolisthesis. For select patients, it may be effective for reducing severe deformity and can be expected to afford good to excellent results. Improved sacral fixation may reduce the rate of hardware-related complications.

Complications in long fusions to the sacrum for adult scoliosis: minimum five-year analysis of fifty patients.

Study Design. A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis with fusion from T10 or higher to S1. Objectives. To document the perioperative and long-term complications and instrumentation problems, and to attempt to determine variables which may influence these problems. It is not a study of curve correction, balance, or functional outcome. Summary of Background Data. Several previous studies from this and other centers have shown a relatively high complication rate for this select group of patients. Various fusion techniques (anterior, posterior, autograft, allograft), various instrumentation techniques, and various immobilization techniques have created confusion as to the best methodology to employ. Minimal 2-year follow-ups have been standard, but longer follow-ups have shown additional problems. Methods. The study cohort consisted of 50 adult patients from a single center who had undergone corrective scoliosis surgery from T10 or higher to the sacrum and who had at least a 5-year minimum follow-up. The mean age was 54 years (range, 18–72), and the mean follow-up was 9.7 years (range, 5–26). All radiographs, office charts, and hospital charts were combed by an independent investigator for complications, which were divided into major and minor, as well as early, intermediate and late. The curvature values and corrections were the subject of a different article, and were not included in this study. Results. There were no deaths or spinal cord injuries. Six patients had nerve root complications, 4 of which totally recovered. Pseudarthrosis was seen in 24% of the patients, only 25% of which were detected within the 2-year follow-up period. Pseudarthrosis was most common at the lumbosacral level. There was no statistical difference in the pseudarthrosis rate between patients with sacral-only fixation versus iliac fixation. Painful implants requiring removal were noted in 11 of the 50 patients. Conclusion. Long fusions to the sacrum in adults with scoliosis continue to have a high complication rate. As compared to the original publications in the 1980s (Kostuik and Hall, Spine 1983;8:489–500; Balderston et al, Spine 1986;11:824–9) the more recent articles have shown a reduction, but not elimination of the pseudarthrosis problem using segmental instrumentation and anterior fusion of the lumbar spine coupled with structural interbody grafting at L4–L5 and L5–S1. Two-year follow-up is inadequate as pseudarthrosis and painful implants often are detected later. Only 3 of the 12 patients with pseudarthrosis were detected within the first 2 years after surgery.

A correlation of radiographic and functional measurements in adult degenerative scoliosis.

Study Design. Retrospective functional and radiographic analysis of symptomatic patients with de novo degenerative lumbar and thoracolumbar scoliosis. Objective. To evaluate the radiographic parameters of symptomatic patients presenting with de novo degenerative adult scoliosis and correlate them with functional scores. Summary of Background Data. Previous studies have been inconclusive as to the correlation of radiographic parameters and clinical symptomatology. Methods. Radiographic analysis of 58 consecutive symptomatic patients with de novo degenerative lumbar and thoracolumbar scoliosis was performed using posteroanterior and lateral 36-inch standing radiographs. Measurements included curve type, curve location, curve magnitude, coronal alignment, sagittal alignment, and anteroposterior and lateral intervertebral olisthesis. Clinical functional data were measured with Oswestry Disability Index, Roland-Morris Disability Questionnaire, and RAND 36-item Health Survey questionnaire. Correlation between clinical data and radiographic data were then calculated. Results. Sagittal balance did not show significant correlation with functional results. However, coronal imbalance (more than 5 cm from midsacrum) affected physical function (P = 0.028) and outcomes (P > 0.05). Also, moderate to severe lateral olisthesis (equal or more than 6 mm) demonstrated higher bodily pain then mild lateral olisthesis (P = 0.005). Good lumbar lordosis correlated positively with health assessment as reflected in SF-36 score (P = 0.039, r = 0.291). Conclusion. Reduced lumbar lordosis and increased lumbosacral scoliosis can affect the general health status of older patients with de novo degenerative scoliosis. Lateral olisthesis, mainly, and anteroposterior olisthesis are important elements of rotatory subluxation in the lumbar curves, which are important radiographic parameters, predicting symptomatology and health status of patients with de novo degenerative scoliosis.

Surgical treatment of neuropathic spinal arthropathy

Surgical treatment of neuropathic spinal arthropathy is traditionally associated with a high rate of complication. Ten patients were treated surgically using contemporary techniques of spinal instrumentation and fusion which included combined anterior and posterior procedures when appropriate. The etiology of the spinal arthropathy was fracture (8 patients) and tumor (2 patients). Mean postsurgical follow-up was 4 years. Solid arthrodesis was obtained in eight patients. Our recommendations for surgical treatment include (a) posterior segmental instrumentation and fusion for single level Charcot involvement, with bone grafting of the anterior single level defect accomplished through the posterolateral approach; (b) restoration of normal sagittal plane contour, with anterior first stage surgery recommended for rigid kyphosis or multiple level Charcot involvement; and (c) leaving no intercurrent unfused segments between new and old fusions in the area of neurologic deficit. Fusion to the pelvis is not always necessary but late arthropathy may develop between the fused segment and the pelvis.