Spine. 33(9): E287-E292 April 20, 2008.

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Metz, Lionel N. BS; Burch, Shane MD, MSc;
Computer-Assisted Surgical Planning and Image-Guided Surgical Navigation in Refractory Adult Scoliosis Surgery: Case Report and Review of the Literature
E287-E292
Abstract
Study Design. Case report and literature review.Objective. In this case report, we present the utility of computer-assisted surgical planning and image-guided surgical navigation in the planning and execution of a major osteotomy to correct severe kyphoscoliosis.Summary of Background Data. Computer-assisted surgical planning is useful to appreciate the three-dimensional nature of scoliotic deformities and allows for operative maneuvers to be simulated on a computer before their implementation in the operating room. Image-guided surgical navigation improves surgical accuracy and can help translate a virtual surgical plan to the operative setting.Methods. We report the case of a 38-year-old woman with severe, congenital kyphoscoliosis refractory to many previous surgeries, who presents with moderate progressive myelopathy and severe pain attributable to a sharp angular deformity at T12. Three-dimensional computed tomography reconstruction and computer-assisted surgical planning were used to determine the optimal corrective osteotomy. The surgical plan was translated to the operating room where a posterior vertebrectomy and instrumented correction were executed with the aid of image-guided surgical navigation.Results. The osteotomy was safely performed resulting in improved sagittal and coronal alignments, as well as, correction of the sharp kyphoscoliotic deformity at the thoracolumbar junction. At 6-month follow-up, the patient's myelopathy and pain had largely resolved and she expressed high satisfaction with the procedure.Conclusion. We advocate this novel application of virtual surgical planning and intraoperative surgical navigation to improve the safety and efficacy of complex spinal deformity corrections

Sayer, Faisal T. MD, MSc; Vitali, Aleksander M. MD; Low, Hu Liang MSc, FRCS(SN); Paquette, Scott MD, FRCS(C); Honey, Christopher R. MD, DPhil, FRCS(C);
Brown-Sequard Syndrome Produced by C3-C4 Cervical Disc Herniation: A Case Report and Review of the Literature.
E279-E282
Abstract
Study Design. The article presents a case in which Brown-Sequard syndrome resulted from a painless C3-C4 disc herniation.Objective. To raise spinal surgeons' awareness of this unusual clinical problem.Summary of Background Data. Brown-Sequard syndrome involves ipsilateral loss of motor function combined with contralateral loss of pain and temperature sensation. Brown-Sequard syndrome is commonly seen in the setting of spinal trauma or an extramedullary spinal neoplasm, but rarely it can be caused by a herniated cervical disc.Methods. A 46-year-old man presented with progressive numbness and weakness in the left arm, mild neck pain, and reduced temperature sensation on the right side of the body. There was weakness in left arm and leg and proximal right lower limb. Magnetic resonance imaging showed large C3-C4 disc herniation compressing the spinal cord at that level. Anterior cervical discectomy and fusion with iliac crest bone graft was performed.Results. Follow-up showed complete resolution of the neck pain, normal sensory function, and complete recovery of motor power in the left upper and right lower limb. There was a slight residual weakness in the left leg.Conclusion. Brown-Sequard syndrome is rarely caused by a cervical disc herniation. This etiology may be underdiagnosed but has a more favorable outcome in those cases where rapid diagnosis is followed by spinal cord decompression

Matsumoto, Morio; Chiba, Kazuhiro ; Toyama, Yoshiaki et al
Surgical Results and Related Factors for Ossification of Posterior Longitudinal Ligament of the Thoracic Spine: A Multi-Institutional Retrospective Study
1034-1041
Abstract
Study Design. Retrospective multi-institutional studyObjective. To describe the surgical outcomes in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to clarify factors related to the surgical outcomes.Summary of Background Data. Detailed analyses of surgical outcomes of T-OPLL have been difficult because of the rarity of this disease.Methods. The subjects were 154 patients with T-OPLL who were surgically treated at 34 institutions between 1998 and 2002. The surgical procedures were laminectomy in 36, laminoplasty in 51, anterior decompression via anterior approach in 25 and via posterior approach in 29, combined anterior and posterior fusion in 8, and sternum splitting approach in 5 patients. Instrumentation was conducted in 52 patients. Assessments were made on (1) The Japanese Orthopedic Association (JOA) scores (full score, 11 points), its recovery rates, (2) factors related to surgical results, and (3) complications and their consequences.Results. (1) The mean JOA score before surgery was 4.6 +/- 2.0 and, 7.1 +/- 2.5 after surgery. The mean recovery rate was 36.8% +/- 47.4%. (2) The recovery rate was 50% or higher in 72 patients (46.8%). Factors significantly related to this were location of the maximum ossification (T1-T4) (odds ratio, 2.43-4.17) and the use of instrumentation (odds ratio, 3.37). (3) The frequent complications were deterioration of myelopathy immediately after surgery in 18 (11.7%) and dural injury in 34 (22.1%) patients.Conclusion. The factors significantly associated with favorable surgical results were maximum ossification located at the upper thoracic spine and use of instrumentation. T-OPLL at the nonkyphotic upper thoracic spine can be treated by laminoplasty that is relatively a safe surgical procedure for neural elements. The use of instrumentation allows correction of kyphosis or prevention of progression of kyphosis, thereby, enhancing and maintaining decompression effect, and its use should be considered with posterior decompression
Stadhouder, Agnita ; Buskens, Erik ; de Klerk, Luuk W. ; Verhaar, Jan A. et al
Traumatic Thoracic and Lumbar Spinal Fractures: Operative or Nonoperative Treatment: Comparison of Two Treatment Strategies by Means of Surgeon Equipoise.
1006-1017
Abstract
Study Design. A center parallel cohort study with blinded inclusion based on clinical equipoise.Objective. To compare outcomes of nonoperative and operative treatment strategies in terms of quality of life and neurologic and functional status.Summary of Background Data. Despite a considerable body of literature, sound evidence regarding the optimal treatment for traumatic thoracic and lumbar spine fractures is lacking.Methods. Medical records of patients hospitalized for traumatic spinal fractures between 1991 and 2002 were identified in 2 trauma centers in the same country with established and different treatment strategies. Eligibility was retrospectively assessed for each case by a panel of orthopaedic surgeons who were representative of the 2 medical centers, and who were blinded to the treatment actually administered. Patients were included in the study when there was disagreement on the suggested treatment method. Thus, 2 comparable groups were identified undergoing nonoperative or operative treatment. Outcome assessment and comparison across groups focused on quality of life, residual pain, neurologic recovery, and employment in the middle-long-term follow-up.Results. Discordance in regards to choice of treatment was identified in 190 (95 treated nonoperative, 95 operative) of 636 potentially eligible patients. Patients were comparable regarding baseline characteristics, except for a somewhat higher proportion of males and neurologic impairment in the operative group. Seventeen percent of the nonoperative and 21% of the operative group developed complications and 3 patients displayed neurologic deterioration for which a treatment change was considered necessary. Follow-up was complete in 79%; mean follow-up time was 6.2 years with a minimum of 2 years. Pain scores, disability indexes, and general health outcome were comparable at follow-up. Compared with matched population norms, outcomes were poorer regardless of treatment method. Neurologic recovery was better in the operative group, but this difference did not reach statistical significance. Multivariate regression analyses revealed that female gender and neurologic impairment were independent predictors of poor functional outcome. Eighty-eight and 83% of the nonoperatively and operatively treated patients were employed at some point after a rehabilitation period.Conclusion. Overall outcome of nonoperative and operative treatment in middle-long-term follow up is comparable, although there seems to be a difference in neurologic recovery patterns. Studies on the cost-effectiveness of treatment options and the patterns of recovery within 2 years after injury would assist in guideline development and stimulate interest for future research

Hay, Douglas FRCS; Izatt, Maree T. BPhty; Adam, Clayton J et al
The Use of Fulcrum Bending Radiographs in Anterior Thoracic Scoliosis Correction: A Consecutive Series of 90 Patients.
999-1005
Abstract
Study Design. A prospective, consecutive series of 90 patients receiving fulcrum bending radiographs before endoscopic anterior scoliosis correction.Objective. To assess the effectiveness of fulcrum bending radiographs in predicting correction of the structural curve in anterior scoliosis surgery for a series of 90 consecutive patients.Summary of Background Data. The fulcrum bending radiograph is highly predictive of scoliosis curve correction for posterior instrumented fixation. However, its use has been questioned in relation to anterior scoliosis surgery due to the disc removal in anterior procedures.Methods. Fulcrum bending radiographs were performed before endoscopic anterior scoliosis correction following the protocol of Cheung and Luk. All patients received a single anterior rod and vertebral body screws using a standard compression technique. In all cases, cleared disc spaces were packed with mulched femoral head allograft. Surgical correction was assessed using 6- to 8-week postoperative standing radiographs. Paired t tests and least squares linear regression analysis were used to compare the preoperative major Cobb angle achieved on the fulcrum bending radiograph with the postoperative Cobb angles for each patient.Results. Mean (+/-SD) major curve correction rate was 60.1% +/- 12.4%. Mean instrumented curve correction rate was 63.7% +/- 11.7%. Mean fulcrum flexibility was 60.8% +/- 15.5%. Mean fulcrum bending correction index was 104%. There was no statistically significant difference between the mean fulcrum bending radiograph Cobb angle (20.4 +/- 9[degrees]) and the mean postoperative major Cobb angle for the structural curve (20.5 +/- 7.1[degrees]).Conclusion. The results of this study show that fulcrum bending radiographs are predictive of surgical correction for anterior scoliosis surgery

Lurie, Jon D.; Tosteson, Anna N. A.; Tosteson, Tor et al
Reliability of Magnetic Resonance Imaging Readings for Lumbar Disc Herniation in the Spine Patient Outcomes Research Trial (SPORT).
991-998
Abstract
Study Design. Assessment of the reliability of standardized magnetic resonance imaging (MRI) interpretations and measurements.Objective. To determine the intra- and inter-reader reliability of MRI parameters relevant to patients with intervertebral disc herniation (IDH), including disc morphology classification, degree of thecal sac compromise, grading of nerve root impingement, and measurements of cross-sectional area of the spinal canal, thecal sac, and disc fragment.Summary of Background Data. MRI is increasingly used to assess patients with sciatica and IDH, but the relationship between specific imaging characteristics and patient outcomes remains uncertain. Although other studies have evaluated the reliability of certain MRI characteristics, comprehensive evaluation of the reliability of readings of herniated disc features on MRI is lacking.Methods. Sixty randomly selected MR images from patients with IDH enrolled in the Spine Patient Outcomes Research Trial were each rated according to defined criteria by 4 independent readers (3 radiologists and 1 orthopedic surgeon). Quantitative measurements were performed separately by 2 other radiologists. A sample of 20 MRIs was re-evaluated by each reader at least 1 month later. Agreement for rating data were assessed with kappa statistics using linear weights. Reliability of the quantitative measurements was assessed using intraclass correlation coefficients (ICCs) and summaries of measurement error.Results. Inter-reader reliability was substantial for disc morphology [overall kappa 0.81 (95% confidence interval (CI): 0.78, 0.85)], moderate for thecal sac compression [overall kappa 0.54 (95% CI: 0.37, 0.68)], and moderate for grading nerve root impingement [overall kappa 0.47 (95% CI: 0.36, 0.56)]. Quantitative measures showed high ICCs of 0.87 to 0.96 for spinal canal and thecal sac cross-sectional areas. Measures of disc fragment area had moderate ICCs of 0.65 to 0.83. Mean absolute differences between measurements ranged from approximately 15% to 20%.Conclusion. Classification of disc morphology showed substantial intra- and inter-reader agreement, whereas thecal sac and nerve root compression showed more moderate reader reliability. Quantitative measures of canal and thecal sac area showed good reliability, whereas measurement of disc fragment area showed more modest reliability

Hoogland, Thomas; van den Brekel-Dijkstra, Karolien et al
Endoscopic Transforaminal Discectomy for Recurrent Lumbar Disc Herniation: A Prospective, Cohort Evaluation of 262 Consecutive Cases
973-978
Abstract
Study Design. A prospective, cohort evaluation of 262 consecutive patients who underwent transforaminal endoscopic excision for recurrent lumbar disc herniation, after previous discectomy.Objective. To review complications and results of the endoscopic transforaminal discectomy (ETD) for recurrent herniated disc with a 2-year follow-up.Summary of Background Data. Recurrent herniation is a significant problem, as scar formation and progressive disc degeneration may lead to increased morbidity after traditional posterior reoperation. The studies published until now on recurrent disc herniation concern various operative techniques, mostly the lumbar microdiscectomy, which is still seen as the standard. The advantage of ETD could be that there is no need to go through the old scar tissue and the procedure can be performed in local anesthesia. The disadvantage may be a long learning curve for the surgeon.Method. Between January 1994 and November 2002, 262 patients with primarily radicular problems underwent an ETD for a recurrent herniated disc. Two hundred and thirty-eight of these patients (90.84%) completed our 2-year follow-up questionnaire. Initial surgery of 82 patients was performed in-house, 180 external. Average age was 46.4 years. The female/male ratio was 29/71%.Results. At 2-year follow-up 85.71% of patients rated the result of the surgery as excellent or good. 9.66% reported a fair and 4.62% patients an unsatisfactory result. Average improvement of back pain of 5.71 points and 5.85 points of leg pain on the VAS scale (1-10). According to Mac Nab, 30.67% of the patients felt fully regenerated, 50% felt their functional capacity to be slightly restricted, 16.81% felt their functional capacity noticeably restricted, and 2.52% felt unimproved or worse. All patients participated in a 3-month follow-up to establish the perioperative complications. The overall complication rate was 10/262 (3.8%), including 3 nerve root irritations and 7 early recurrent herniations (<3 month). There was no case of infection or discitis.After 3 months and within 2 years, 4 patients have been treated for a recurrent herniated disc in our own center and 7 patients have been treated elsewhere, resulting in a recurrence rate 11/238 (4.62%).Conclusion. ETD for recurrent disc herniation seems to be an effective method with few complications and a high patient satisfaction

Hoogendoorn, Roel J. W. ; Helder, Marco N. ; Kroeze, Robert Jan et al
Reproducible Long-term Disc Degeneration in a Large Animal Model.
949-954
Abstract
Study Design. Twelve goats were chemically degenerated and the development of the degenerative signs was followed for 26 weeks to evaluate the progression of the induced degeneration. The results were also compared with a previous study to determine the reproducibility.Objectives. The purpose of this study was determine whether this Chondroitinase ABC (CABC) induced goat model is reproducible and to study the development of the degeneration in time up to 26 weeks.Summary of Background Data. Injecting CABC into goat intervertebral discs results in mild disc degeneration after 12 weeks. Spontaneous recovery or leveling off of the degeneration has been reported before and is relevant when the goat model is used in regeneration studies. Reproducibility of the induced degeneration is relevant as well.Methods. Twelve goats were used in this study. The development of degeneration was studied after the injection of 0.25 U/mL CABC intradiscally. The development of degenerative signs was studied after 18 (n = 6) and 26 (n = 6) weeks by means of radiograph, magnetic resonance imaging, macroscopic analysis, and histology and biochemical evaluation. The induced degeneration was compared with the results from a previous study, in which degeneration was induced similarly and analysis was performed after 12 weeks.Results. The severity of the degenerative signs was mild and was consequently present in all parameters analyzed. When compared with the results after 12 weeks, the degeneration was similar in the present study. Spontaneous recovery was not observed up to 26 weeks.Conclusion. The injection with CABC in the intervertebral disc reproducibly results in mild disc degeneration in the goat. These findings corroborate the goat model as a suitable large animal model to evaluate mild disc degeneration and potential new therapies

Ruetten, Sebastian ; Komp, Martin ;Merk, Harry et al
Full-Endoscopic Cervical Posterior Foraminotomy for the Operation of Lateral Disc Herniations Using 5.9-mm Endoscopes: A Prospective, Randomized, Controlled Study
940-948
Abstract
Study Design. Prospective, randomized, controlled study of patients with lateral cervical disc herniations, operated either in a full-endoscopic posterior or conventional microsurgical anterior technique.Objective. Comparison of results of cervical discectomies in full-endoscopic posterior foraminotomy technique with the conventional microsurgical anterior decompression and fusion.Summary of Background Data. Anterior cervical decompression and fusion is the standard procedure for operation of cervical disc herniations with radicular arm pain. Mobility-preserving posterior foraminotomy is the most common alternative in the case of lateral localization of the pathology. Despite good clinical results, problems may arise due to traumatization of the access. Endoscopic techniques are considered standard in many areas, since they may offer advantages in surgical technique and rehabilitation. These days, all disc herniations of the lumbar spine can be operated in full-endoscopic technique. With the full-endoscopic posterior cervical foraminotomy a procedures is available for cervical disc operations.Methods. One hundred and seventy-five patients with full-endoscopic posterior or microsurgical anterior cervical discectomy underwent follow-up for 2 years. In addition to general and specific parameters, the following measuring instruments were used: VAS, German version North American Spine Society Instrument, Hilibrand Criteria.Results. After surgery 87.4% of the patients no longer had arm pain, and 9.2% had occasional pain. The clinical results were the same in both groups. There were no significant difference between the groups in the revision or complication rate. The full-endoscopic technique brought advantages in operation technique, preserving mobility, rehabilitation, and traumatization.Conclusion. The recorded results show that the full-endoscopic posterior foraminotomy is a sufficient and safe supplement and alternative to conventional procedures when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention.