Posterior Surgical Decompression Research Articles

370 Is There an Optimal Surgical Approach in Degenerative Cervical Myelopathy?: An Individual Participant Data Meta-Analysis

INTRODUCTION: Contradictions exist about impact of anterior vs. posterior surgical approach on outcomes of degenerative cervical myelopathy (DCM). METHODS: Individual patient data of subjects who underwent surgery for DCM was identified from a pooled dataset of the AO Spine CSM-North America, CSM-International, and CSM-Protect clinical studies. Primary outcomes were changes in short form 36 Physical Component Summary score (SF36-PCS) and mJOA score at 12 months. Secondary outcomes were change in total Neck Disability Index (NDI) score and SF36 Mental Component Summary score (SF36-MCS). Two comparison cohorts were created: i) anterior surgery and ii) posterior surgery. One-stage mixed-effects meta-analysis with study and treatment exposure as random effects was performed and reported with mean differences and 95% confidence intervals. A subgroup analysis planned a priori in mild DCM patients (mJOA 15-17) was performed. RESULTS: A total of 979 patients met eligibility criteria. Patients who had anterior decompressive surgery experienced greater improvements at 1yr of follow-up than those who underwent posterior decompressive surgery in SF36-PCS score (adjusted MD 1.57 [95% CI 0.11 to 3.03], p = 0.0348) and NDI score (adjusted MD 3.32 [95% CI 0.58 to 6.05], p = 0.0172). A greater proportion of patients that underwent anterior surgery achieved clinically important recovery of their NDI (OR 1.49 [95% CI 1.15 to 1.93], p = 0.002; aOR 1.46 [95% CI 1.08 to 1.96], p = 0.013) and SF36-PCS scores at 1yr (OR 1.45 [95% CI 1.12 to 1.88], p = 0.004, aOR 1.34 [95% CI 1.00 to 1.80], p = 0.052). In patients with mild DCM (n = 186), patients who underwent anterior decompressive surgery experienced greater improvements in SF36-PCS score, mJOA score, and Neck Disability Index score than posterior surgical patients. CONCLUSIONS: Anterior surgical decompression for DCM is associated with greater improvements in 1yr patient-reported outcomes than posterior surgical decompression.

1075 The Effect of Regional Procedural Preference on Outcomes After Posterior Decompression for Degenerative Cervical Myelopathy: Individual Participant Data Meta-Analysis of a Prospective, Multinational Dataset of 1047 Cases

INTRODUCTION: There is considerable debate regarding the relative effectiveness of laminoplasty vs. laminectomy and fusion for posterior surgical decompression of degenerative cervical myelopathy (DCM). METHODS: Subjects with DCM that underwent posterior decompression was derived from three independent, prospective, multicentre clinical trials (CSM-NA, CSM-I, CSM-Protect). Primary endpoint was change in SF36-PCS (minimum clinically important difference [MCID] 4) at 1yr compared to pre-operative assessment. Secondary endpoints were change in mJOA (MCID 2) score, Neck Disability Index (NDI; MCID 15) score, NDI Pain Intensity score, and SF36-MCS (MCID 4) score. Two comparison cohorts were created: i) laminoplasty (LP) and ii) laminectomy and fusion (LF). One-stage hierarchical mixed-effects meta-analyses with study and treatment exposure as random effects were performed. As subgroup analysis, the influence of procedural volume between LP-predominant sites, LF-predominant sites, and volume-equivalent sites was investigated. RESULTS: From a total of 1047 patients with DCM, 369 patients met eligibility criteria. There was geographic variability in surgical choice with higher rates of laminectomy and fusion in Brazil and Canada and higher laminoplasty rates in Japan and India. USA had similar rates of LF and LP. When compared to LF-predominant sites, LP-predominant sites achieved greater rates of MCID for mJOA at 1yr (85.4% v. 68.7%, p=0.036) with their predominant technique. There were no significant differences in MCID rates of NDI, SF36-PCS, or SF36-MCS. When comparing LF-predominant and LP-predominant sites with USA, a volume equivalent site, there were no significant differences in MCID rates of all outcomes. CONCLUSIONS: Sites that primarily used LP achieved greater rate of MCID in mJOA with laminoplasty than laminectomy with fusion from primarily LF sites. This suggests that experience with either LP or LF can drive outcomes which has interesting healthcare delivery implications.

Comparison of laminoplasty and posterior fusion surgery for cervical ossification of posterior longitudinal ligament

This prospective multicenter study, established by the Japanese Ministry of Health, Labour and Welfare and involving 27 institutions, aimed to compare postoperative outcomes between laminoplasty (LM) and posterior fusion (PF) for cervical ossification of the posterior longitudinal ligament (OPLL), in order to address the controversy surrounding the role of instrumented fusion in cases of posterior surgical decompression for OPLL. 478 patients were considered for participation in the study; from among them, 189 (137 and 52 patients with LM and PF, respectively) were included and evaluated using the Japanese Orthopaedic Association (JOA) scores, the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and radiographical measurements. Basic demographic and radiographical data were reviewed, and the propensity to choose a surgical procedure was calculated. Preoperatively, there were no significant differences among the participants in terms of patient backgrounds, radiographical measurements (K-line or cervical alignment on X-ray, OPLL occupation ratio on computed tomography, increased signal intensity change on magnetic resonance imaging), or clinical status (JOA score and JOACMEQ) after adjustments. The overall risk of perioperative complications was found to be lower with LM (odds ratio [OR] 0.40, p = 0.006), and the rate of C5 palsy occurrence was significantly lower with LM (OR 0.11, p = 0.0002) than with PF. The range of motion (20.91° ± 1.05° and 9.38° ± 1.24°, p < 0.0001) in patients who had PF was significantly smaller than in those who had LM. However, multivariable logistic regression analysis showed no significant difference among the participants in JOA score, JOA recovery rate, or JOACMEQ improvement at two years. In contrast, OPLL progression was greater in the LM group than in the PF group (OR 2.73, p = 0.0002). Both LM and PF for cervical myelopathy due to OPLL had resulted in comparable postoperative outcomes at 2 years after surgery.

Neurosurgery guidelines for the care of people with spina bifida

Myelomeningocele (MMC) arises from an early neural developmental anomaly and results in a variety of structural abnormalities and associated functional neurologic deficits. As such, neurologic issues are central to virtually all clinical problems. Neurosurgical intervention strives to correct or improve these defects and prevent secondary complications. These interventions include closure of the open myelomeningocele and management (across the life span) of hydrocephalus, the Chiari II malformation (C2M) and tethered spinal cord (TSC). The development of pre-natal closure techniques and reports of improved outcome with in-utero closure (IUMC) have revolutionized the neurosurgical approach to myelomeningocele. Controversies remain surrounding patient selection, maternal risks, technique of IUMC (endoscopic vs. open) and long-term outcomes. However, real gains include reduced rates of hydrocephalus, modestly improved motor capabilities and reduction in C2M morbidity. For many decades, the cornerstone of treatment of hydrocephalus for many decades has been the placement and support of ventricular shunts. Endoscopic third ventriculostomy (ETV) with or without choroid plexus coagulation (ETV/CPC) is an appealing alternate strategy that avoids the morbidity and complications associated with shunts. The exact criteria for ETV-CPC candidacy and best metrics for outcome analysis remain active areas of debate and controversy. Similarly, neurosurgical management C2M, has centered upon the indications and clinical thresholds for performing posterior fossa surgical decompression. Tethered spinal cord management incorporates the diagnosis and surgical management of adhesions formed at the initial closure site, the consequent longitudinal traction related stress on the cord and the resulting neurologic signs and symptoms.

Morphometric analysis of cervical interlaminar space for posterior surgical approach and decompression.

The purpose of this study is to provide a morphometric description of the bony margins of the interlaminar spaces by level in the cervical spine for guidance of safe posterior cervical surgical dissection and decompression. We also aim to describe the impact of increasing static cervical lordosis on the overlap between the lamina. Morphometric measurements of the interlaminar space were performed on 100 consecutive cervical spine CT scans of patients ranging in age from 18 to 50years were selected. Three raters performed measurements of the interlaminar height measured using two techniques (true interlaminar height and surgical interlaminar height), and interlaminar width from C2-C3 to C7-T1. In total, 100 patients were included. The true interlaminar height was greatest at C2-3, C3-4, C4-5 (5.2 ± 1.4-1.8mm) and smallest at C6-7 (4.4 ± 1.3mm). Surgical interlaminar height was greatest at C3-4 (4.2 ± 1.7) and smallest at C6-7 (3.0 ± 1.3mm). The widest interlaminar space was observed at C3-4 (27.1 ± 2.1mm) and most narrow at C7-T1 (20.9 ± 2.4mm). Following multivariate regression, male gender was associated with greater interlaminar widths at each cervical level between C4 and T1 (Table 2). While greater patient height was associated with larger interlaminar height (true and surgical) and width at C2-3 and C4-5, weight was not independently associated with the interlaminar measurements. Increasing C2-C7 lordosis was significantly associated with decreasing true and surgical interlaminar heights at all levels except C7-T1, but was not associated with differences between interlaminar width. The study provides a morphometric analysis of interlaminar anatomy in the cervical spine. Surgeons can apply this information in their pre-operative plan to safely approach the posterior cervical spine.

Surgical Treatment of Congenital Basilar Invagination with Different Pathological Characteristics: Report of 139 Cases

Objective To describe the different pathological characteristics of congenital basilar invaginations and discuss the surgical treatment of such cases. Methods A total of 139 patients diagnosed with basilar invaginations underwent surgical treatment from 2008 to 2015. Based on Atul Goel's classification and simultaneous consideration of atlantoaxial dislocation or syringomyelia, the cases were subdivided into four groups. Individualized posterior surgical decompression and/or atlantoaxial reset procedures were performed to correct atlantoaxial dislocation, decompress the brain stem, or resolve syringomyelia. The indications and critical points of each procedure were documented. Results All 139 patients were surgically treated; 27 patients (19.4%) had underwent at least one decompression surgery previously. On an average, there was gratifying clinical improvement based on the Japanese Orthopaedic Association score analysis. One patient exhibited severe postoperative infection, and the fusion instrument was removed. One patient experienced fracture of internal fixation. Two patients exhibited persistent respiratory symptoms at early stages after the surgery. Four patients felt worse at the latest follow-up. There was no surgical mortality. The poor outcome/ morbidity in this series was 5.8% (8/139). Conclusion The different pathological image characteristics of congenital basilar invaginations based on the presence or absence of syringomyelia and/or atlantoaxial dislocation, reflected the pathological features of complicated basilar invaginations more accurately. Based on these features, different posterior decompression and/or reset procedures, combined with occipitocervical fusion and C1-2 fusion, could be tailored to different patients. These individualized surgeries could reduce surgical complications, decrease morbidity and mortality, and further promote positive outcomes.

Outcome of a Resident Spine Surgical Skills Training Program.

Cadaver training lab. To determine if a technical cadaver skills training lab for spinal surgery increases resident confidence, satisfaction in training, and perception of operating room safety. Resident training is an important topic in the setting of work hour reform. The use of supplemental materials such as videos, sawbones, and simulators may become important to adequately train orthopedic residents. At present, there are no established curricula for training orthopedic surgery residents on anatomy and common procedures encountered during a spinal surgery rotation. Residents were assembled into teams of a PGY-5 and PGY-2 and/or PGY-1 to perform dissection and procedures on 5 fresh-frozen spine cadavers. With attending and spine fellow supervision, residents performed anterior cervical, posterior cervical, and posterior thoracolumbar surgical exposure, decompression, and fusion procedures in the operating room using surgical tools and instrumentation. Residents were then queried about their confidence levels, satisfaction in training, and perception of safety using a Likert scale (0-10). Strong agreement (scores ≥8) and strong disagreement (scores ≤3) and correlations were evaluated. Seventeen residents completed the training program (7 PGY-1s, 2 PGY-2s, and 8 PGY-5s). After the training, the majority of residents strongly agreed that they had an increased confidence of their own abilities (59%). A significant majority (65%) of residents strongly agreed that they were satisfied with the benefits provided by the training program. Compared with other methods of education, residents strongly agreed that the training was more helpful than textbook chapters (94%), sawbones (94%), web-based training (94%), or a virtual-based (completely electronic) training (94%). After the training, residents strongly agreed that the training improved feelings of preparation (47%), safety (41%), and ability to prevent intraoperative errors (41%). The vast majority of residents strongly agreed "Before performing surgery on me, I would want a resident to perform this cadaveric training" (88%). These results demonstrate that team-based, cadaveric training with adequate attending supervision, before onset of a spine surgical rotation, may lead to high resident confidence, satisfaction in training, and perception of patient safety.

Surgical treatment of congenital basilar invagination with different pathological characteristics: Report of 139 cases

Objective To describe the different pathological characteristics of congenital basilar invaginations and discuss the surgical treatment of such cases. Methods A total of 139 patients diagnosed with basilar invaginations underwent surgical treatment from 2008 to 2015. Based on Atul Goel's classification and simultaneous consideration of atlantoaxial dislocation or syringomyelia, the cases were subdivided into four groups. Individualized posterior surgical decompression and/or atlantoaxial reset procedures were performed to correct atlantoaxial dislocation, decompress the brain stem, or resolve syringomyelia. The indications and critical points of each procedure were documented. Results All 139 patients were surgically treated; 27 patients (19.4%) had underwent at least one decompression surgery previously. On an average, there was gratifying clinical improvement based on the Japanese Orthopaedic Association score analysis. One patient exhibited severe post-operative infection, and the fusion instrument was removed. One patient experienced fracture of internal fixation. Two patients exhibited persistent respiratory symptoms at early stages after the surgery. Four patients felt worse at the latest follow-up. There was no surgical mortality. The poor outcome/ morbidity in this series was 5.8% (8/139). Conclusion The different pathological image characteristics of congenital basilar invaginations based on the presence or absence of syringomyelia and/or atlantoaxial dislocation, reflected the pathological features of complicated basilar invaginations more accurately. Based on these features, different posterior decompression and/or reset procedures, combined with occipitocervical fusion and C1-2 fusion, could be tailored to different patients. These individualized surgeries could reduce surgical complications, decrease morbidity and mortality, and further promote positive outcomes.

The Morphometric Study of Degenerative Lateral Canal Stenosis at L4-L5 and L5-S1 Using Magnetic Resonance Imaging (MRI): Feasibility Analysis for Posterior Surgical Decompression.

This study was to evaluate the morphological features of degenerative spinal stenosis and adequacy of lateral canal stenosis decompression via unilateral and bilateral laminectomy. Measurements of facet joint angulation (FJA), mid facet point (MFP), mid facet point distance (MFPD), the narrowest point of the lateral spinal canal (NPLC) and the narrowest point of the lateral spinal canal distance (NPLCD) were performed. At L4L5 of the right and left side, the mean distance between the lateral border of the dura and MFP was 1.0 ± 0.2 cm and 1.0 ± 0.3cm respectively. The mean NPLC was seen at 0.7 ± 0.3 and 0.7 ± 0.3 cm cm from the dura. At L5S1 of the right and left side, the mean distance between the lateral border of the dura and MFP was 1.2± 0.2 and 1.3 ± 0.2 cm respectively. The mean NPLC was seen at 0.8 ± 0.4 and 0.9 ± 0.5 cm from the dura. Unilateral laminectomy may result in incomplete decompression.

Bow hunter's syndrome: the use of dynamic magnetic resonance angiography and intraoperative fluorescent angiography

Bow hunter's syndrome is a diagnosis typically made using dynamic digital subtraction angiography. The authors present the case of a 68-year-old woman who presented with symptoms consistent with bow hunter's syndrome that was accurately diagnosed utilizing noninvasive dynamic MR angiography. The dynamic MR angiogram clearly illustrated unilateral vertebral artery compression upon turning of the head. A subsequent CT of the cervical spine showed a ventral C-1 osteophyte within the foramen. The patient underwent posterior surgical decompression of the left vertebral artery. Sufficient decompression was confirmed using intraoperative fluorescent angiography with the patient's head turned. This case report is the first to illustrate that dynamic MR angiography can be a reliable and less invasive diagnostic tool. It can also be used to confirm sufficient postoperative decompression and monitor for recurrence. Intraoperative fluorescent angiography has been previously used in the evaluation of intracranial and extracranial vascular patency. This report is the first to show that fluorescent angiography can offer rapid and reliable intraoperative evaluation of vertebral artery decompression in bow hunter's syndrome.

Complete traumatic fracture-dislocation L3-L4 of the lumbar spine

Complete traumatic fracture-dislocation of the lumbar spine is a rare spinal injury often leading to death. Surgical intervention is an effective treatment modality to decrease mortality. Our patient was a 16 year old boy who had a collision caused by fall from a construction material lifter. He was referred to our hospital with waist trauma. Later, the patient underwent posterior surgical decompression during which vertebral column restoration by long segment fixation was performed. After surgery there were no significant changes in the patient condition.

Posterior Surgical Decompression and Fusion Augmented with Internal Fixation in Thoracic and Lumbar Spondylodiscitis; is it Possible?

Background Data: Posterior surgical treatment of spinal infections was adopted since 1912. However, most authors strictly advocated anterior or anterolateral debridement and subsequent bone grafting and fixation. These procedures oftenbear a high risk for elderly and debilitated patients. Purpose: To assess the efficacy of posterior surgical decompression, fusion and fixation in thoracic and lumbar spine spondylodiscitis. Study Design: A retrospective clinical case study.Patients and Methods: Fifteen patients suffering from thoracic and lumbar spondylodiscitis, both tuberculous and non-tuberculous, underwent posterior surgical decompression with posterolateral and interbody fusion augmentedwith posterior fixation, according to the degree of vertebral wedging, the kyphotic angle and high surgical risk for anterior procedures. Results: Neither of our patients deteriorated as regards the motor power. Improvement of the kyphotic and lordotic angles was evident in post-operative images. Eleven of our 15 cases (73%) improved to variable degrees, (from C to E Frankel grading); four patients had the same motor power as pre-operatively. Conclusion: It is possible to perform posterior surgical decompression and fusion augmented with internal fixation in thoracic & lumbar spondylodiscitis in oneor more of the following: (1) those of high anesthetic risk for circumferential surgery, (2) kyphotic angel not more than 10o beyond the normal range in dorsal spine (3) the percentage of the anterior and posterior vertebral height is ≤ 30%(4) diminished or loss of lumbar lordosis, (5) average body weight. (2013ESJ046)

Abstract WMP46: Rotational Ischemic Vertebral Artery Compression (RIVAC) Syndrome Due to Cervical Facet Hypertrophy and Uncinate Process Osteophyte: Review of Seven Consecutive Cases

Introduction: The authors propose a new terminology, Rotational Ischemic Vertebral Artery Compression (RIVAC) syndrome, to describe patients who present with TIA or stroke from compression of the cervical vertebral artery (VA) below C2 by facet hypertrophy or uncinate process osteophyte associated with rotation of the head. The authors review clinical presentation, radiological findings, and management of 7 consecutive cases. Methods: Prospective analysis of 7 consecutive cases of RIVAC syndrome was performed between 2004 and 2012. We reviewed peri-operative imaging, method of treatment, and clinical and angiographic outcome. Results: A total of 6 patients (mean 66+/- 4 years) presented with stroke (N=2) or TIA including reproducible dizziness, vertigo, or syncope (N=4) associated with rotation of the head. Pre-operative dynamic cerebral angiogram showed near complete occlusion of cervical VA (N=2) or severe stenosis (60 to 80%) (N=5) during rotation of the head. The location of cervical VA compression was as follows: right C3-4 (N=1), left C4-5 (N=3), left C5-6 (N=2) and left C6-7 (N=1). Treatment included endovascular stent placement of VA without open surgery (N=1), endovascular stent placement of VA followed by partial left C5-6 factectomy 2 years later (N=1), posterior surgical decompression of VA along with bilateral facet screw fixation (N=4), and anterior cervical discectomy and fusion (N=1). Follow up dynamic cerebral angiograms and CTA angiogram of neck (6 months to 3 years) showed resolution of VA compression on rotation of head in all patients except for one who had lost in follow up. Clinical evaluation (range of 1 to 48 months) showed no recurrent stroke or TIA in all patients (mRS score of 0, N=6 and mRS of 3, N=1). Conclusion: RIVAC syndrome should be recognized as an important cause of posterior circulation TIA or stroke associated with rotation of head. Pre-operative dynamic cerebral angiogram and CT angiogram of neck are essential in localization and characterization of the level and cause of VA compression. Open surgical decompression and fixation appears to be safe and effective treatment of patients with RIVAC syndrome.

Does ossification of the posterior longitudinal ligament progress after laminoplasty? Radiographic and clinical evidence of ossification of the posterior longitudinal ligament lesion growth and the risk factors for late neurologic deterioration

Ossification of the posterior longitudinal ligament (OPLL) is a disease process characterized by progressive growth and calcification resulting in spinal canal compromise and serious neurological sequelae in advanced cases. Historically, OPLL has most commonly been treated with posterior surgical decompression. Although this procedure indirectly decompresses the spinal cord, it does not address the offending pathological entity, and further growth of the lesion may result in delayed neurological deterioration. This fact is particularly relevant because a number of long-term studies have revealed both longitudinal and transverse disease progression in individuals treated both surgically and conservatively. Despite these high rates of radiographically documented progression, however, the rate of neurological decline in patients undergoing posterior surgery with laminoplasty is low. In this article, the authors review the pathophysiology of OPLL, evidence of disease progression, and outcome data addressing conservative and surgical treatments.

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

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

Cervical Stenosis and Spastic Quadriparesis in Morquio Disease (MPS IV)

White, Klane K. MD, MSc1; Steinman, Suzanne MD2; Mubarak, Scott J. MD2 Author Information

Proprioceptive Recovery of Patients With Cervical Myelopathy After Surgical Decompression

A prospective observational study. To determine whether proprioceptive deficit recovers after surgery and whether proprioceptive evaluation can predict functional outcome in cervical myelopathy patients. Proprioceptive sensation plays an important role in smooth, coordinated movement of the limbs. Information about proprioception ascends through the dorsal columns in the spinal cord. In severe compressive myelopathy, proprioceptive ability would be reduced and could be improved after surgical decompression. However, there have been few studies concerning proprioceptive impairment in cervical myelopathy. The study group included 26 cervical myelopathy patients who underwent posterior surgical decompression. Knee proprioception was assessed by joint position sense, which was evaluated by measuring the error angle when the subjects tried to reproduce the predetermined angle by extension and by flexion. Proprioceptive deficit in the study group was evaluated, compared with age-matched normal subjects. Postoperative recovery and correlation to functional status was analyzed in the study group. The Japanese Orthopedic Association (JOA) scores were used for functional evaluation. The error angles were significantly higher in the study group than those in the control group before surgery. All patients in the study group finally had improvement of the error angles by a year after surgery. The average of error angles in the study group was improved 2 weeks after surgery; however, no changes were observed later. There was significant correlation between the improvement rate of the error angles 2 weeks after surgery and that of the JOA scores 2 years after surgery. There were 9 patients who had worsened proprioception 2 weeks after surgery either by extension or by flexion, all of whom had poor functional outcome. Knee proprioception was impaired in cervical myelopathy and recovered after surgical posterior decompression. Proprioceptive improvement at 2 weeks correlates with the degree of improvement in JOA scores at 2 years after surgery.

Cervical myelopathy associated with degenerative spine disease and ossification of the posterior longitudinal ligament.

Cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament are two of the leading etiologies of spinal cord damage in older patients. For most patients, the natural history is one of slow stepwise decline in function. With nonsurgical therapy only 30 to 50% of patients are expected to stabilize. Surgical options include anterior and posterior surgical decompression, spinal canal expansion, and spinal column stabilization. Prospective, randomized trials with standardized outcome measures are needed to clarify the benefit of surgery conclusively.

Long-term disability assessment after surgical treatment of low grade spondylolisthesis.

The aim of this study was to determine whether assessment of back surgery with disability scores is relevant. We also attempted to answer the question of whether this evaluation should be conducted by a surgeon or a medical doctor. This retrospective study analyzes the long-term outcome (average follow-up 7 years, range: 3-12) of 40 patients (mean age: 46.2 years) treated by posterior surgical decompression, posterolateral arthrodesis, with or without instrumentation, for symptomatic low-grade spondylolisthesis. All patients were interviewed postoperatively and examined the same day by an orthopedic surgeon, who was not involved in the patients' treatment, as well as by a medical doctor rehabilitation specialist. Impairment was assessed by a standardized clinical examination and by visual analog scales (VAS) of pain. Disability was assessed using two scales: the Quebec disability scale and the Beaujon scale. Anxiety and depression were assessed with a validated specific questionnaire (HAD). Patient's perceived handicap was assessed on a 100-mm VAS. Our results show that the scores of the two disability scales were highly correlated with the patient's overall satisfaction ( r = 0.73 and 0.77 for the Quebec scale and the Beaujon scale, respectively). The intraclass correlation coefficient showed very good or excellent correlation between the data collected by the surgeon and the rehabilitation specialist, ranging from 0.8 to 0.97. This finding clearly demonstrates that interview by a surgeon who is not involved in the patient's treatment does not influence the patient's assessment in terms of impairment, disability, or handicap. Moreover, our results suggest that disability scales are the most relevant outcome measures in the assessment of spine surgery.

Hydatid Disease of the Spine

Vertebral hydatidosis is a relatively silent and slowly progressive disease with a latent period of many years. The prognosis for neurologic recovery in hydatid disease of the spine generally is regarded as poor and posterior surgical decompression is associated with a high recurrence rate. Reported here are the results after a long-term followup of four patients with hydatid disease of the spine with neurologic deficit which significantly improved after anterior surgical decompression and anthelmintic therapy. Adequate preoperative evaluation with magnetic resonance imaging and computed tomography scanning is essential in localizing the lesions and planning the surgical approach. The authors recommend radical excision of the involved vertebra and anthelmintic drugs to control the disease process.