Age- and sex-related variations in sagittal sacropelvic morphology and balance in asymptomatic adults.

INTRODUCTION: Many studies suggest the importance of the sagittal sacropelvic balance and morphology in spinal and hip disorders. This study describes the normal age- and sex-related changes in sacropelvic morphology and balance in a prospective cohort of asymptomatic adults without spinal disorder. MATERIALS AND METHODS: A prospective cohort of 709 asymptomatic adults without spinal pathology was recruited. There were 354 males and 355 females aged 37.9 ± 14.7 and 35.7 ± 13.9 years, respectively. For each subjects, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured from standing lateral radiographs. Ratios of SS to PI (SS/PI), PT to PI (PT/PI), and PT to SS (PT/SS) were also calculated. RESULTS: There was no significant difference in PI (pelvic incidence), SS (sacral slope), PT (pelvic tilt), PT/PI, SS/PI, or PT/SS between males and females. The mean ± 2 standard deviations (SD) range was 32°-74°, 0°-27°, and 24°-55° for PI, PT and SS, respectively. The mean ± 2 SD range was greater than 0.5 for SS/PI and less than 0.5 for PT/PI. PI was not related to age in either sex group. PT, SS, PT/PI, SS/PI, and PT/SS presented only weak correlation coefficients (r ≤ 0.21) with respect to age. CONCLUSION: The current study presents the largest cohort of asymptomatic adults in the literature dedicated to the evaluation of sagittal sacropelvic morphology and balance. The range of values corresponding to the mean ± 2 SD can provide invaluable information to clinicians about the normal range of values expected in 95% of the normal population.

Do Curve Characteristics Influence Stenosis Location and Occurrence of Radicular Pain in Adult Degenerative Scoliosis?

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The aim of this study was to describe the various locations of spinal stenosis (LSS) in lumbar scoliosis and its related clinical symptoms. INTRODUCTION: Adults with lumbar scoliosis often present with pain and disability. Association of scoliosis and stenosis is not rare, but remains sparsely explored. Consequences of scoliosis on stenosis location and treatment remain debatable. METHODS: Patients operated for symptomatic LSS with lumbar scoliosis (Cobb angle >20°) from 2015 to 2016 were included. All patients completed preoperative clinical and neurologic examination. Coronal and sagittal radiographic parameters, rotatory subluxation (RS), and spondylolisthesis were analyzed on full spine radiographs. Computed tomographic scan multiplanar reconstructions were performed to measure central, foraminal, and lateral recess stenosis, from T10 to the sacrum. RESULTS: A total of 76 patients were included (69 ± 9 years old, 77% female). Sixty percent had neurogenic claudication, and L5 was the most common radicular pain (41%). The mean Cobb angle was 33° ± 16°. Overall, 35 (46%) patients had coronal malalignment; in 69%, side of the coronal tilt corresponded to side of the concavity of the lumbosacral curve. Sixty patients had RS (most frequent level L3-L4). In 50% of the cohort, RS was located at the junction between the lumbar and lumbosacral curves. In 70% (n = 53) of the patients, central stenosis occurred at the junction between the lumbar and lumbosacral curves. Foraminal and lateral stenosis were most frequently observed in the concavity of the distal lumbosacral curve. L5 radicular pain was significantly more frequent in case of lumbosacral contra-curve and right coronal malalignment. CONCLUSION: LSS is frequent in lumbar scoliosis. Relationships exist between curve characteristics and symptomatic LSS in lumbar scoliosis; especially, concavity of the lumbosacral contra-curve and the junctional level between the lumbar curve and the lumbosacral contra-curve. Therefore, accurate analysis of stenosis in ASD seems mandatory, to at least perform decompression because perfect planned treatment for stenosis and scoliosis correction might not always be possible because of the patient's general health status. LEVEL OF EVIDENCE: Level 4.

[Digestive obstruction: an unusual complication of hereditary multiple exostoses]. / Obstruction digestive : une complication exceptionnelle d'une maladie exostosante.

Hereditary multiple exostoses is an autosomal dominant bone disorder characterized by multiple cartilaginous tumors growing outward from metaphyses of long bones. These tumors are usually located in long bones of the limbs. Exostosis also called osteochondroma can cause many complications, the most serious being malignant transformation as chondrosarcoma. We report a rare phenotype of this disease in a young male patient who presents digestive symptoms caused by a voluminous degenerated lumbar exostosis with anterior abdominal development.

[Long-term survival analysis after surgical management for degenerative lumbar stenosis]. / Etude à long terme du risque de réintervention après traitement chirurgical d'une sténose canalaire lombaire.

PURPOSE OF THE STUDY: The short- and mid-term symptom-relief of surgical treatment for lumbar stenosis is generally acknowledged, but the probability of a long-term reoperation remains to be studied. The purpose of this work was to determine the long-term risk of reoperation after surgical treatment of degenerative lumbar stenosis and to search for factors influencing this probability. MATERIAL AND METHODS: All patients who underwent from 1989 to 1992 surgical treatment for degenerative lumbar spine stenosis were included in this work. At last follow-up, we noted functional outcome using a specific self-administered questionnaire, patient satisfaction, lumbalgia and radiculalgia using a visual analog scale, SF36 quality-of-life, reoperation or not with time since first operation if performed and the reasons and modalities of the reoperation. The probability of reoperation was determined with the acturarial method. A Cox model was used to search for factors linked with the probability of reoperation; variables studied were: age, comorbid factors, extent of the release, posterolateral arthrodesis or not, extent of the potential fusion, use or not of instrumentation for arthrodesis. RESULTS AND DISCUSSION: The study included 262 patients. At last follow-up, 61 patients had died a mean 3.7+/-3 years after the operation; only one of these patients had a second operation 22 months after the first. Forty-four patients were lost to follow-up at mean 6.6+/-3 years. Among these 44 patients, four had a second operation during their initial follow-up at mean 47 months. One hundred fifty-seven patients were retained for this analysis at mean 15+/-1 years follow-up. Among these 157 patients, 29 had a second operation a mean 75 months after the first. There were four reasons for reoperating: insufficient release, destabilization within or above the zone of release, development or renewed zone of stenosis, development or renewed discal herniation. The risk of a second operation was 7.4% [95% CI 4.8-11.6], 15.4% [95% CI 10.7-21.1] and 16.5% [95% CI 11.7-219] at five, 10 and 15 years respectively after the first operation. Among the risk factors studied, only one had a significant impact on reoperation: extent of the zone of release (p=0.003). Compared with a release limited to one level, the risk of reoperation after release of three levels or more was five times greater [95% CI 1.8-12.7].

[Paraplegia after interlaminar epidural steroid injection: a case report]. / Paraplégie secondaire à une infiltration épidurale interlamaire lombaire, à propos d'un cas.

We report the first case of paraplegia observed after epidural steroid injection in the upper spine. The patient was a 42-year-old male who underwent surgery two years earlier for stenosis of the lumbar spine from L2 to the sacrum leading to early manifestations of an equina cauda syndrome. This first operation provided satisfactory function with complete resolution of the objective neurological symptoms. The patient later developed bilateral radiculalgia involving the L3 and L4 territories and was treated by radio-guided epidural steroid injection (125 mg hydrocortancyl) delivered in the L1-L2 interlaminar space. The injection was achieved with no technical difficulty and there was no injury to the dural sac. Immediately after the injection, the patient developed complete motor and sensorial paraplegia from T12. CT and MRI performed 30 min and 4h, respectively, after the accident revealed a medium-sized discal herniation behind the L2 body. No other lesion was observed. Emergency surgery was performed for radicular release but to no avail. The patient's neurological status remained unchanged and four days later the T2 MRI sequence revealed a high-intensity intramedullar signal in the cone. The diagnosis of ischemia of the medullary cone was retained, hypothetically by injury to the dominant radiculomedullary artery via an undetermined mechanism. This complication has been previously described after upper foraminal steroid injections but not after intralaminar epidural steroid injection.

[Influence of disc height on outcome of posterolateral fusion]. / Influence de la hauteur discale sur le devenir d'une arthrodèse postérolaterale.

PURPOSE OF THE STUDY: Experimentally, posterolateral fusion only provides incomplete control of flexion-extension, rotation and lateral inclination forces. The stability deficit increases with increasing height of the anterior intervertebral space, which for some warrants the adjunction of an intersomatic arthrodesis in addition to the posterolateral graft. Few studies have been devoted to the impact of disc height on the outcome of posterolateral fusion. The purpose of this work was to investigate the spinal segment immobilized by the posterolateral fusion: height of the anterior intervertebral space, the clinical and radiographic impact of changes in disc height, and the short- and long-term impact of disc height measured preoperatively on clinical and radiographic outcome. MATERIALS AND METHODS: In order to obtain a homogeneous group of patients, the series was limited to patients undergoing posterolateral arthrodesis for degenerative spondylolisthesis, in combination with radicular release. This was a retrospective analysis of a consecutive series of 66 patients with mean 52 months follow-up (range 3-63 months). A dedicated self-administered questionnaire was used to collect data on pre- and postoperative function, the SF-36 quality of life score, and patient satisfaction. Pre- and postoperative (early, one year, last follow-up) radiographic data were recorded: olisthesic level, disc height, intervertebral angle, intervertebral mobility (angular, anteroposterior), and global measures of sagittal balance (thoracic kyphosis, lumbar lordosis, T9 sagittal tilt, pelvic version, pelvic incidence, sacral slope). SpineView was used for all measures. Univariate analysis searched for correlations between variation in disc height and early postoperative function and quality of fusion at last follow-up. Multivariate analysis was applied to the following preoperative parameters: intervertebral angle, disc height, intervertebral mobility, sagittal balance parameters, use of osteosynthesis or not. RESULTS: At the olisthesic level, there was a 30% mean decrease in disc height and intervertebral angle. These variations were not correlated with functional outcome or quality of fusion observed at last follow-up. Disc height preoperatively did not affect these variations. The only factor correlated with decreased disc height was T9 sagittal tilt: disc height decreased more when T9 sagittal tilt approached 0 degrees . DISCUSSION: In this very restricted context (retrospective study, short arthrodesis for degenerative spondylolisthesis), we were unable to find any evidence supporting the notion that high disc height is an argument which should favor complementary intersomatic arthrodesis in combination with posterolateral fusion. Analysis of the spinal balance in the sagittal plane would probably allow a more pertinent assessment of the specific needs of individual patients.

Digital metastasis of nasopharyngeal carcinoma: a surgical trap. Case report and literature review.

Acrometastases are rare and often misdiagnosed or overlooked. We report the case of an 80-year-old patient in whom an acrometastasis in the right long finger from a nasopharyngeal carcinoma was diagnosed. The treatment consisted of amputation through the proximal phalanx and resulted in a good recovery. To our knowledge, no case of acrometastasis from this origin has been reported in the literature to date. A literature review is also presented regarding acrometastasis diagnosis and treatment.

[Superior mesenteric artery syndrome following correction of spinal deformity: case report and review of the literature]. / Syndrome de la pince aorto-mésentérique après correction d'une déformation rachidienne.

Superior mesenteric artery syndrome is a rare complication which can develop after surgical correction of a spinal deformity. The syndrome is caused by an extrinsic compression on the third portion of the duodenum by the aorta posteriorly and the mesenteric artery anteriorly. We report here a case of aortomesenteric compression of the duodenum secondary to surgical correction of lower thoracic scoliosis in a 19-year-old female. The patient presented vomiting and intestinal obstruction ten days after spinal surgery. Treatment consisted in exclusive parenteral nutrition followed by careful surveillance and progressive reintroduction of oral food intake to avoid unnecessary surgery. Young thin subjects are predominantly exposed to this type of complication. The body mass index is a good indication to identify subjects at risk. Symptoms of upper gastrointestinal obstruction develop seven to ten days after surgery. Diagnosis is based on transit studies using a hydroluble contrast agent which reveals major gastric dilation and a clear interruption of the transit at the level of the third duodenum as well as retrograde peristaltism. Medical treatment should be undertaken first and is effective in the large majority of cases. Surgery may be proposed only in the event of failure. Recurrence is exceptional. Early diagnosis, delivery of clear information for the patient and family and multidisciplinary management are important points to consider for proper care for this complication which if neglected can become life-threatening.

Surgical treatment of degenerative spondylolisthesis.

Degenerative spondylolisthesis is a common pathology, often causing lumbar canal stenosis. There is, however, no strong consensus regarding the various medical and surgical treatments available. Surgery is indicated mainly for perceived functional impairment; when the indication is accepted, several questions determine the choice of surgical strategy. Improvement in neurological symptoms is one of the main treatment objectives. For this, it is useful to perform radicular decompression. Some authors recommend indirect decompression by interbody fusion (ALIF, TLIF, XLIF), others by means of an interspinous spacer but the most frequent technique is direct posterior decompression. In degenerative spondylolisthesis, functional results seem to be improved by associating stabilization to decompression, to prevent secondary destabilization. The following risk factors for destabilization are recognized: anteroposterior hypermobility, angular hypermobility and large disc height. Two stabilization techniques have been described: "dynamic" stabilization and (more frequently) fusion. Spinal instrumentation is frequently associated to fusion, in which case, it is essential for fusion position and length to take account of pelvic incidence and the patient's overall pattern of balance. Posterolateral fusion may be completed by interbody fusion (PLIF or TLIF). This has the theoretic advantage of increasing graft area and stability, restoring local lordosis and opening the foramina. Surgical treatment of degenerative spondylolisthesis usually consists in posterior release associated to instrumented fusion, but some cases can be more complex. It is essential for treatment planning to take account of the patient's general health status as well as symptomatology and global and segmental alignment.

Neurological deficit secondary to a pre-sacral abscess with epidural extension up to L3: A case report and literature review.

Isolated epidural abscesses are uncommon lesions. Surgical treatment may be difficult due to the extension of these lesions. We present a case of a pelvic abscess spreading along the path of the sciatic nerve to the gluteus muscles and the lumbar canal, causing neurological compression; requiring surgical treatment with three simultaneous approaches.

Evolution and complications after surgery for spine deformation in patients with Parkinson's disease.

INTRODUCTION: Surgical treatment of spinal deformity is high risk in patients suffering from Parkinson's disease (PD). Several series have already reported a high rate of complications. However, none of these studies included more than 40 patients and none of the risk factors of complications were described. The aim of this study was to describe the rate and risk factors of revision surgery as well as the clinical outcome at the last visit in a large multicenter study of PD patients operated for spinal deformities. METHODS: A multicenter retrospective study included arthrodesis for spinal deformity in patients with PD. Clinical and surgical data including revision surgeries were collected. Assessment of functional outcomes at last follow-up was classified in 3 grades and spinal balance was assessed on anteroposterior and lateral plain X-rays of the entire spine. RESULTS: Forty-eight patients were included. Median age was 67 years old (range 41-80). Median follow-up was 27 months. The rate of surgical revision was 42%. Eighty per cent of revisions were performed for chronic mechanical complication. Global results were considered to be good in 17 patients (35%), doubtful in 17 patients (35%) and a failure in 14 patients (30%), for the whole series. CONCLUSIONS: The results of surgery for spinal deformities in patients with Parkinson disease vary with a high rate of complications and revisions. Nevertheless, these results should be seen in relation to the natural progression of these spinal deformities once spinal imbalance has developed. The association between preoperative clinical balance and final outcome suggests that early surgery can probably play a role in treatment. LEVEL OF EVIDENCE: Level IV (e.g. case series).

[Total knee arthroplasty for recent severe fracture of the proximal tibial epiphysis in the elderly subject]. / Arthroplastie totale de genou pour fracture récente grave de l'épiphyse tibiale proximale chez le sujet âgé.

PURPOSE OF THE STUDY: Bone comminution, serious cartilage damage, and the poor mechanical quality of osteoporotic bone create a difficult challenge for osteosynthesis of joint fractures in the elderly subject. Poor results with certain hip, elbow and shoulder fractures have lead certain authors to propose emergency arthroplasty in selected cases. We report our experience with four knee arthroplasties implanted for recent severe fracture of the proximal tibial epiphysis in elderly subjects. MATERIAL AND METHODS: Four independent patients aged over 75 years presented a severe comminutive fracture of the proximal epiphysis of the tibia (Three Schatzker 5, one Schatzker 4). After obtaining the patients' informed consent, early knee arthroplasty was performed. A long-stem cemented tibial piece was used on which the epiphysis was reconstructed. Implants providing support for ligament deficits were used in all cases. Immediate weight-bearing was authorized. RESULTS: Follow-up ranged from two to seven years. The IKS function score (15, 60, 100, 100) depended on the patient's general status. The IKS knee score was excellent for three knees (90, 95, 95), and fair in one (45). Re-operations were not needed in any of the patients. All x-rays showed bone healing with correctly aligned limbs (less than 2 degrees deformation). There were no lucent lines at last follow-up. DISCUSSION: Early arthroplasty for complex fractures of the proximal epiphysis of the tibia is a realistic option. Using a cemented long-stem tibial piece ensures primary stability sufficient for early weight-bearing before bone healing. Use of a constrained prosthesis, or better a hinged prosthesis, can be questioned but avoids the difficulty of ligament balance on an osteoporotic knee with a destroyed joint surface. None of the patients required reoperation and the results in terms of pain were excellent. The overall outcome depends on the general status of the patient.

Sacral stress fracture after lumbar and lumbosacral fusion. How to manage it? A proposition based on three cases and literature review.

Sacral fracture after lumbosacral instrumentation could be a source of prolonged pain and a late autonomy recovery in old patients. Diagnosis remains difficult and usually delayed. No clear consensus for efficient treatment of this complication has been defined. Aim of this study was to determine how to manage them. Three patients who sustained sacral fracture after instrumented lumbosacral fusion performed for degenerative disease of the spine are discussed. History, physical examinations' findings and radiographic features are presented. Pertinent literature was analyzed. All patients complained of unspecific low back and buttock pain a few weeks after index surgery. Diagnosis was done on CT-scan. We always choose revision surgery with good functional results. Sacral stress fracture has to be reminded behind unspecific buttock or low back pain. CT-scan seems to be the best radiological test to do the diagnosis. Surgical treatment is recommended when lumbar lordosis and pelvic incidence mismatched.

Radiologic adjacent segment degeneration 2 years after lumbar fusion for degenerative spondylolisthesis.

INTRODUCTION: Lumbar fusion is now a currently accepted treatment for degenerative lumbar spondylolisthesis (DLSP), but may induce adjacent segment degeneration (ASD). The present study hypothesis was that there are radiological parameters associated with ASD. The study objective was to determine predictive factors of ASD. MATERIAL AND METHODS: A single-center retrospective study included patients operated on between 2006 and 2013 for DLSP. Radiological parameters were analyzed on preoperative, immediate postoperative and final follow-up lateral X-ray. ASD was defined by the following adjacent segment criteria:>3mm anteroposterior translation,>10° segmental kyphosis, or>50% loss of disc height. RESULTS: One hundred and seven patients were included: 79% female; mean age, 67±10.2 years. Fusion involved 1 level in 67% of cases and 2 or more in 33%, with transforaminal lumbar interbody fusion (TLIF) in 27% of cases. There was overall significant gain in lumbar lordosis (mean, 3.1°; P=0.04). At a mean 27.8 months' follow-up, 29% of cases showed ASD and 10% required surgical reintervention. Preoperative anterior imbalance and long fusion (>2 levels) were significantly associated with ASD (OR=2.81, 95% CI [1.17-6.74] versus OR=2.76, 95% CI [1.15-6.63]). There were no significant differences according to postoperative radiological parameters, or to TLIF (OR=1.8, 95% CI [0.7-4.4]). CONCLUSION: Twenty-nine percent of patients developed ASD, with a surgical revision rate of 10%. ASD risk factors comprised high number of instrumented levels and preoperative sagittal imbalance. LEVEL OF EVIDENCE: IV, retrospective cohort.

Reduction and fusion in high-grade L5-S1 spondylolisthesis by a single posterior approach. Results in 50 patients.

INTRODUCTION: Treatment strategies in high-grade L5-S1 spondylolisthesis are controversial. Reduction of slippage, correction of lumbosacral kyphosis and the necessity of a complementary anterior approach are debated in the literature. The present study reports clinical and radiological outcome for reduction and instrumented fusion on a single posterior approach. MATERIAL AND METHOD: A retrospective study included all consecutive adolescent and young adult patients operated on by a single surgeon (D.C.) for high-grade (Meyerding 3-4-5) L5-S1 spondylolisthesis. The technique consisted in reduction of lumbosacral kyphosis and posterolateral fusion on a single posterior approach without resection of the sacral dome or complementary anterior approach. Only cases of adult ptosis required impacted tibial interbody graft. Clinical complications, radiologic lumbopelvic results and sagittal balance were analyzed at last follow-up. RESULTS: Fifty patients, with a mean age at surgery of 21±11 years, were followed up for a mean 5.5±4.6 years. Mean lumbosacral angle was reduced by 25° (from 76° to 101°; P<0.05), and mean listhesis grade by >50% (from 75% to 23%; P<0.0001), without correction loss at last follow-up. C7 sagittal offset was corrected (from 8° to 4°; P<0.05), with harmonization of lumbar (from 57° to 64°; P<0.001) and thoracic curvature (from 37° to 44°; P=0.1). Seventeen patients (34%) showed postoperative radicular deficit, without sequelae at last follow-up. There were no cauda equina lesions. Bone fusion was achieved in 42 patients (84%), in the same surgical step. After revision by complementary interbody graft, there was no residual non-union. CONCLUSION: Surgery on a single posterior approach gave reliable results in high-grade spondylolisthesis in adolescents and young adults. The technique is not however, free of risk (transient neurologic deficit and non-union), and patients should be forewarned. Complementary interbody graft can be reserved to adult ptosis with incomplete reduction of lumbosacral kyphosis and to revision surgery for non-union. LEVEL OF EVIDENCE: IV, retrospective study.

[Complications of surgical treatment of spinal deformities: a prospective multicentric study of 3311 patients]. / Les complications du traitement chirurgical des déviations rachidiennes: etude prospective multicentrique d'une cohorte de 3311 patients.

PURPOSE OF THE STUDY: The incidence of complications secondary to surgical treatment of spinal deformations remains imprecise. The purpose of this prospective multicentric observational study was to assess the incidence of intra- and postoperative complications secondary to this type of surgery to detail the observed complications and to identify favoring factors. MATERIAL AND METHODS: For this study, we included 3311 patients who underwent surgery during a 12-month period for spinal deformation, defined as idiopathic or secondary scoliosis or kyphosis, irrespective of the localization, severity, or type of surgery performed. Four main categories of complications were studied: general, infectious, neurological, and mechanical. Pre- and intraoperative variables recorded were: epidemiological and morphological data, history of surgery for the same spinal deformation, comorbid conditions, type of deformation treated (nature, anatomic localization, severity, reducibility), type of surgery performed (approach, duration of the operation), operative blood loss, extent and localization of the fusion, associated neurological release, vertebral osteotomy or not, type of graft used. Two types of analysis were performed. The first was a descriptive analysis to detail the overall incidence of complications and the incidence of each of the four main categories. The second was a multivariate analysis designed to determine factors significantly associated with complication occurrence. RESULTS: Mean age of the cohort was 27 +/- 18 years; 6.8% of the patients had had a prior operation for the spinal deformation. The deformation was scoliosis in 90% (mean angle 56 +/- 20 degrees) and kyphosis in 10% (mean angle 47 +/- 23 degrees). An isolated posterior approach was used for 72.5% of patients, an isolated anterior approach for 6.4%, and a combined anteroposterior approach for 21.1%. Seven hundred four patients (21.3%) had one or more complications (850 complications) during or shortly after their operation. The incidences of general, infectious, mechanical and neurological complications were: 5.7%, 4.7%, 11.5%, and 1.8% respectively. Globally, considering all types of complications, the following factors were found to be significantly associated with complication occurrence: patient age, ASA score, extent of the fusion, presence of vertebral osteotomy, inclusion of the sacrum in the arthrodesis, and initial angle of the treated deformation. For patients with scoliosis, the following factors were significantly associated with a secondary central neurological disorder: initial angle of the deformation, use of vertebral osteotomy, type of curvature with greater risk for thoracic curvatures and double thoracic and lumbar curvatures. CONCLUSION: This work enabled us to determine the overall rate of complications after surgical treatment of spinal deformations. Certain risk factors related with complication occurrence were identified, but the heterogeneous nature of the population and the methodology used to identify these factors only allowed detection of trends. A future study by etiological group or focusing on specific complications should allow a more precise analysis of these risk factors. This overall rate of complications should be used to better inform patients and their family about the risks of this type of surgery.

[Sagittal balance of the spine and degenerative spondylolisthesis]. / Analyse de l'équilibre sagittal du rachis dans les spondylolisthésis dégénératifs.

PURPOSE OF THE STUDY: Several reports have examined the pathophysiology of degenerative spondylolisthesis. Very little work has however been devoted to the influence of spinal balance in the sagittal plane in its pathogenesis. The purpose of this work was to present a descriptive analysis of pelvic and spinal sagittal balance in a cohort of seventy patients treated for degenerative spondylolisthesis and to compare findings with those established in a population of 250 volunteers. The goal was to deduct pathophysiological hypotheses and identify therapeutic implications. MATERIAL AND METHODS: Seventy patients were included in this study. The following variables were noted: pelvic incidence and version, sacral slope, lumbar lordosis, thoracic kyphosis, T9 sagittal tilt and S1-S2 angle. These variables were measured on digitalized lateral views of the spine using a dedicated software (SpineView). Univariate analysis of the values obtained was performed to identify the variable distributions. Multivariate analysis was applied to study the relationships between these variables and to better define perturbations of spinal balance in the anteroposterior plane. The findings were compared with those obtained in a control population. RESULTS: One of the essential characteristics of the cohort of patients with degenerative spondylolisthesis was the presence of an exaggerated pelvic incidence (62.6 degrees versus 54.7 degrees in the control population). The most significant determinants of T9 sagittal tilt (which reflects sagittal balance) were: pelvic version, pelvic incidence, lumbar lordosis, and L4-S1 local lordosis. One-third of our patients presented posterior tilt due to exaggerated thoracic kyphosis. The high pelvic incidence, via hyperlordosis and increased pelvic version, could be one of the factors favoring degenerative disease of the spinal unit. CONCLUSIONS: This work enabled us to better describe sagittal balance in patients with degenerative spondylolisthesis and to propose hypotheses concerning the underlying mechanism of progressive degeneration. We emphasize the diversity of spinal balance in these patients and the different therapeutic implications.

Clinical and stereoradiographic analysis of adult spinal deformity with and without rotatory subluxation.

INTRODUCTION: In degenerative adult spinal deformity (ASD), sagittal malalignment and rotatory subluxation (RS) correlate with clinical symptomatology. RS is defined as axial rotation with lateral listhesis. Stereoradiography, recently developed for medical applications, provides full-body standing radiographs and 3D reconstruction of the spine, with low radiation dose. HYPOTHESIS: 3D stereoradiography improves analysis of RS and of its relations with transverse plane and spinopelvic parameters and clinical impact. MATERIAL AND METHODS: One hundred and thirty adults with lumbar ASD and full-spine EOS® radiographs (EOS Imaging, Paris, France) were included. Spinopelvic sagittal parameters and lateral listhesis in the coronal plane were measured. The transverse plane study parameters were: apical axial vertebral rotation (apex AVR), axial intervertebral rotation (AIR) and torsion index (TI). Two groups were compared: with RS (lateral listhesis>5mm) and without RS (without lateral listhesis exceeding 5mm: non-RS). Correlations between radiologic and clinical data were assessed. RESULTS: RS patients were significantly older, with larger Cobb angle (37.4° vs. 26.6°, P=0.0001), more severe sagittal deformity, and greater apex AVR and TI (respectively: 22.9° vs. 11.3°, P<0.001; and 41.0° vs. 19.9°, P<0.001). Ten percent of patients had AIR>10° without visible RS on 2D radiographs. RS patients reported significantly more frequent low back pain and radiculalgia. DISCUSSION: In this EOS® study, ASD patients with RS had greater coronal curvature and sagittal and transverse deformity, as well as greater pain. Further transverse plane analysis could allow earlier diagnosis and prognosis to guide management. LEVEL OF EVIDENCE: 4, retrospective study.

Spinal deformity and instability after multilevel cervical laminectomy for spondylotic myelopathy.

STUDY DESIGN: A retrospective radiographic and medical record analysis of 58 patients. OBJECTIVES: To describe the incidence and consequences of cervical spinal deformity and instability after multilevel laminectomy in adult patients with myelopathy caused by cervical spondylosis and to determine the usefulness of preoperative dynamic roentgenographic films in the prevention of postoperative destabilization. SUMMARY OF BACKGROUND DATA: Extensive cervical laminectomy has been widely used in the treatment of progressive myelopathy secondary to stenotic conditions. Complications of this procedure, including spinal instability, accelerated spondylotic changes, postoperative spinal deformity, and constriction of the dura mater by formation of extradural scar tissue formation have been recognized. However, the frequency of these complications is probably overestimated, and their effect on clinical outcome remains unknown. METHODS: Fifty-eight patients older than 30 years who underwent a laminectomy at more than three levels without fusion for myelopathy secondary to cervical spondylosis were reviewed retrospectively with an average follow-up of 3.6 years. Functional results were evaluated according to the Japanese Orthopaedic Association's scoring system. Lateral views in neutral position, in flexion, and in extension of the preoperative cervical roentgenograms were analyzed in comparison with the last follow-up films to identify the changes in the curvature of the cervical column, in the range of motion of the neck, and in the intervertebral angular mobility and anteroposterior displacement of the vertebral bodies and finally to quantify the incidence of spinal instability. RESULTS: In 18 patients (31%), postoperative changes in the type of cervical spine curvature developed. Fifteen patients (25%) had destabilization at one or more levels. Deformities of the cervical spine occurring after surgery do not appear to cause symptoms or neurologic abnormalities. Destabilization required repeat surgery in 3 patients. All the levels appearing to be destabilized on the postoperative films were hypermobile on the preoperative dynamic radiographs. Preoperative olisthesis Without hypermobility is not a factor of risk in postoperative destabilization. CONCLUSIONS: The use of preoperative dynamic radiographs should improve the selection of patients undergoing laminectomy for the treatment of multilevel cervical cord compression. Dynamic radiographs may also reinforce the need for such adjunctive procedures as fusion and instrumentation, to prevent postoperative destabilization. Preoperative olisthesis with hypermobility in sagittal or horizontal planes must be fused and instrumented.

Cervical pseudarthrosis in ankylosing spondylitis. A case report.

STUDY DESIGN: This report illustrates two different cases of cervical pseudarthrosis in ankylosing spondylitis. OBJECTIVES: To point out the extreme rarity of this condition at cervical level, to discuss the pathogenesis, and to stress the necessity of surgical management. SUMMARY AND BACKGROUND DATA: Pathogenesis of pseudarthrosis in ankylosing spondylitis is discussed. Several factors are involved: trauma, which may be major or minor and undetected; stress fracture; and inflammatory changes. Major trauma was the cause of pseudarthrosis in the first patient, whereas stress fracture and inflammatory changes were the probable causes in patient 2. In patient 1 there were signs and symptoms of cord compression. Patient 2 was referred because of functional disability resulting from kyphosis and because of potential neurologic risk. METHODS: Cervical fusion was performed in both patients. Patient 1 underwent posterior fusion; patient 2 had combined fusion. Patient 1 also underwent a lamineotomy. RESULTS: The course of the disorder after surgery was uneventful in both patients. Neurologic symptoms subsided in patient 1; kyphosis was corrected in patient 2. Both patients resumed their preoperative activities. Follow-up evaluation was done 6 years after surgery in patient 1 and 2 years after surgery in patient 2. CONCLUSIONS: Pseudarthrosis of the cervical spine in ankylosing spondylitis is extremely rare. Presentation of the two patients was different in terms of pathogenesis and signs and symptoms. Surgical treatment is advocated for this disorder.