OP-1 Compared with Iliac Crest Autograft in Instrumented Posterolateral Fusion: A Randomized, Multicenter Non-Inferiority Trial.

BACKGROUND: Spinal fusion with the use of autograft is a commonly performed procedure. However, harvesting of bone from the iliac crest is associated with complications. Bone morphogenetic proteins (BMPs) are extensively used as alternatives, often without sufficient evidence of safety and efficacy. The purpose of this study was to investigate non-inferiority of osteogenic protein-1 (OP-1, also known as BMP-7) in comparison with iliac crest bone graft in posterolateral fusions. METHODS: This study was a randomized, controlled multicenter trial. Patients who underwent a single-level instrumented posterolateral fusion of the lumbar spine for degenerative or isthmic spondylolisthesis with symptoms of neurological compression were randomized to receive OP-1 combined with local bone (OP-1 group) or autologous bone graft from the iliac crest combined with local bone (autograft group). The primary outcome was overall success, defined as a combination of clinical success and evidence of fusion on computed tomography (CT) scans, at one year postoperatively. RESULTS: One hundred and nineteen patients were included in the study, and analysis of the overall outcome was performed for 113. Non-inferiority of OP-1 compared with iliac crest autograft was not found at one year, with a success rate of 40% in the OP-1 group versus 54% in the autograft group (risk difference = -13.3%, 90% confidence interval [CI] = -28.6% to +2.10%). This was due to the lower rate of fusion (the primary aim of OP-1 application) seen on the CT scans in the OP-1 group (54% versus 74% in the autograft group, p = 0.03). There were no adverse events that could be directly related to the use of OP-1. CONCLUSIONS: OP-1 with a collagen carrier was not as effective as autologous iliac crest bone for achieving fusion and cannot be recommended in instrumented posterolateral lumbar fusion procedures. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Influence of transforaminal lumbar interbody fusion procedures on spinal and pelvic parameters of sagittal balance.

INTRODUCTION: Restitution of sagittal balance is important after lumbar fusion, because it improves fusion rate and may reduce the rate of adjacent segment disease. The purpose of the present study was to describe the impact of transforaminal lumbar interbody fusion (TLIF) procedures on pelvic and spinal parameters and sagittal balance. MATERIALS AND METHODS: Forty-five patients who had single-level TLIF were included in this study. Pelvic and spinal radiological parameters of sagittal balance were measured preoperatively, postoperatively and at latest follow-up. RESULTS: Age at surgery averaged 58.4 (±9.6) years. Mean follow-up was 35.1 months (±4.1). Twenty-nine percent of the patients exhibited anterior imbalance preoperatively, with high pelvic tilt (17.6° ± 7.9°). Of the 32 (71%) patients well balanced before the procedure, 22 (70%) had a large pelvic tilt (>20°), due to retroversion of the pelvis as an adaptive response to the loss of lordosis. Three dural tears (7%) were reported intraoperatively. Interbody cages were more posterior than intended in 27% of the cases. Disc height and lumbar lordosis at fusion level significantly increased postoperatively (p < 0.05 and p < 0.001). Pelvic tilt was significantly reduced (p < 0.01) postoperatively, whereas the global sagittal balance was not significantly modified (p = 0.07). CONCLUSION: Single-level circumferential fusion helps patients reducing their pelvic compensation, but the amount of correction does not allow for complete correction of sagittal imbalance.

Oncogenous osteomalacia and myopericytoma of the thoracic spine: a case report.

STUDY DESIGN: A case report. OBJECTIVE: To illustrate a rare case of oncogenous osteomalacia caused by a spinal thoracic myopericytoma. SUMMARY OF BACKGROUND DATA: Osteomalacia related to a tumor is well known. The cause of the disorder is usually a highly vascularized, benign tumor of mesenchymal origin. Location of the tumor in the spine is very rare. Removal of the tumor is followed by resolution of osteomalacia. METHODS: Diagnosis of oseomalacia was established on the presence of cardinal clinical, biologic, and radiologic features of osteomalacia. Localization of the tumor at T5 and T6 levels was obtained by magnetic resonance imaging. Surgical treatment consisted in a circumferential correction-fusion with hemivertebrectomy of T5 and T6 and tumor removal. RESULTS: Tumor removal was rapidly followed by disappearance of the clinical symptoms of osteomalacia, and by correction of hypophosphatemia. At 2-years follow-up, no recurrence of the tumor was detectable on imaging studies-the correction fusion remained stable. Histologically, the tumor was classified as a myopericytoma. There was no relapse of the clinical features of osteomalacia. However, secondary recurrence of the biologic markers due to an incomplete tumor removal was disclosed. CONCLUSION: Removal of the tumor was followed by healing of the clinical features of osteomalacia, demonstrating the causal connection between the myopericytoma and the osteopathy.

Acute spontaneous spinal epidural hematoma: an important differential diagnosis in patients under clopidogrel therapy.

BACKGROUND CONTEXT: Spontaneous spinal epidural hematoma (SSEH) is an infrequent spinal pathology. Although it is related to numerous risk factors, its etiology remains unclear. PURPOSE: The aim of this article was to review the most important data in the literature about SSEH and to propose clopidogrel (Plavix) therapy as a risk factor. STUDY DESIGN: Case report. METHODS: A 79-year-old woman was hospitalized in our unit with posterior thoracic pain and urinary retention of 72 hours duration. A clinical history was taken, and laboratory and imaging tests were performed. Urgent surgical decompression was performed, showing an epidural hematoma. Postoperative bacteriological cultures were negative, and microscopic analysis confirmed the diagnosis. RESULTS: For this patient, clopidogrel (Plavix) therapy was the only risk factor related to SSEH. CONCLUSIONS: In any patient under clopidogrel (Plavix): Sanofi-Synthelabo, Bristol-Myers Squibb/Sanofi Pharmaceuticals) therapy and with a typical clinical presentation, SSEH should be suspected and quickly diagnosed, regardless of hemostatic status or the absence of other major risk factors.

Is there a sagittal imbalance of the spine in isthmic spondylolisthesis? A correlation study.

Recent studies suggested a predominant role of spinopelvic parameters to explain lumbosacral spondylolisthesis pathogeny. We compare the pelvic incidence and other parameters of sagittal spinopelvic balance in adolescents and young adults with developmental spondylolisthesis to those parameters in a control group of healthy volunteers. We compared the angular parameters of the sagittal balance of the spine in a cohort of 244 patients with a developmental L5-S1 spondylolisthesis with those of a control cohort of 300 healthy volunteers. A descriptive and correlation study was performed. The L5 anterior slipping and lumbosacral kyphosis in spondylolisthesis patients was described using multiple regression analysis study. Our study demonstrates that the related measures of sagittal spinopelvic alignment are disturbed in adolescents and young adults with developmental spondylolisthesis. These subjects stand with an increased sacral slope, pelvic tilt and lumbar lordosis but with a decreased thoracic kyphosis. Pelvic incidence was significantly higher in spondylolisthesis patients as compared with controls but was not clearly correlated with the grade of slipping. We showed the same "sagittal balance strategy" in spondylolisthesis patients as in the control group regarding correlations between pelvic incidence, sacral slope, pelvic tilt and lumbar lordosis. We believe that the lumbosacral kyphosis is a stronger factor than pelvic incidence which need to be taken into account as a predominant factor in theories of pathogenesis of lumbosacral spondylolithesis. We thus believe that increased lumbar lordosis associated with L5-S1 spondylolisthesis is secondary to the high pelvic incidence and is an important factor causing high shear stresses at the L5-S1 pars interarticularis. However, the "local" sagittal imbalance of the lumbosacral junction is compensated by adjacent mobile segments in the upper lumbar spine, the pelvis orientation and the thoracic spine. The result is not optimal but a satisfactory global sagittal balance of the trunk, even in the most severe grade of slipping.

Traumatic dislocation of the lumbosacral junction diagnosis, anatomical classification and surgical strategy.

PURPOSE OF THE STUDY: Traumatic lumbosacral dislocation is a rare lesion often characterised by a fracture dislocation of L5-S1 articular facets associated with anterior L5 slipping. Because of its rarity, the surgical strategy of lumbosacral traumatic dislocation remains controversial. We report the most important series of traumatic lumbosacral dislocation. The cases of six men and five women are presented. We discuss the diagnosis and surgical treatment options regarding the different type of lesions. A moderate anterior slipping of L5 over S1 was present in eight cases. The lesion was a bilateral lumbosacral fracture dislocation in eight cases, a pure lateral dislocation in two cases and a unilateral rotatory dislocation in one case. Patients were multiple-trauma patients in eight cases. A radicular deficit was present in two cases. All patients were treated surgically with a posterior osteosynthesis and fusion. A circumferential fusion was made in six cases. In four cases, the anterior fusion was made during the posterior approach. The postoperative course was favorable in all the cases. One patient necessitated secondarily an iterative posterior lumbosacral fixation and anterior fibular bone graft because of a lumbosacral pseudarthrosis. Traumatic dislocation of the lumbosacral junction is a rare and severe spinal fracture which occurs in patients after high energy trauma and could be initially misdiagnosed. We devised a new classification based on anatomical lesions. Treatment is always surgical, requiring reduction, osteosynthesis, and fusion. In case of L5 anterior slipping, it is crucial to assess the L5S1 disc by MRI or surgical exploration for disc disruption. In such case, we recommend to perform circumferential fusion to prevent lumbosacral pseudarthrodesis.

Spinal tuberculosis: a longitudinal study with clinical, laboratory, and imaging outcomes.

OBJECTIVES: To study imaging changes associated with spinal tuberculosis (ST) over time and evaluate their association with clinical and laboratory data. METHODS: Between 1997 and 2004, patients with proven ST in our institution were prospectively enrolled and treated for 1 year. Clinical and laboratory data were collected at baseline and every 3 months. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed at baseline. MRI was performed at least twice during treatment and at the end of treatment. RESULTS: Nineteen patients were enrolled; neurological signs were present at baseline in 14 patients (74%). Initial MRI/CT findings comprised (in percentages of patients) the following: paravertebral abscesses (100/100); intradiscal abscesses (47/0); and epidural abscesses (82/24) with spinal cord compression (64/18) or radicular compression (36/0). Edema of the vertebral body was observed on initial MRI in all the patients. Full follow-up data were available for 15 patients: all were cured with a mean follow-up of 25 months after the end of treatment. Weight gain was nearly maximal at 6 months, and pain relief was achieved within 9 months. C-reactive protein returned to normal after 3 months. On MRI, all epidural abscesses disappeared within 9 months; paravertebral abscesses disappeared after 3, 6, and 12 months in 45, 50, and 85% of patients, respectively. Vertebral body signal converted to a fatty signal in 75% of cases at 12 months. CONCLUSIONS: Significant imaging abnormalities can persist after successful treatment of ST. These findings suggest that MRI need not be repeated in patients with clinical and laboratory improvement.

Neurological and functional outcome after unstable cervicothoracic junction injury treated by posterior reduction and synthesis.

BACKGROUND CONTEXT: Unstable lesions of the cervicothoracic junction present a severe clinical problem for diagnosis, treatment, and prognosis. PURPOSE: The objective of the present study was to evaluate the neurological and functional outcomes following surgical treatments which combine in all cases posterior reduction and stabilization. STUDY DESIGN: Retrospective clinical and radiological study. PATIENT SAMPLES: Between September 1996 and September 2003, 30 patients underwent surgery for unstable fracture at the cervicothoracic junction. This group included 23 patients who sustained a motor vehicle accident, 5 who had fallen from a height, 1 case of ballistic trauma, and 1 person injured by diving in shallow water. There were 22 male and 8 female patients aged between 18 and 80, with an average age of 49. In 18 cases the lesion level was vertebra C7, in 5 cases vertebra T1, in 2 cases vertebra T2, and in 5 cases vertebra T3. Neurologically, on initial clinical examination 16 patients were classified Frankel A, 6 Frankel B, 2 Frankel C, and 6 Frankel D. Surgically, all the patients underwent posterior reduction and synthesis. Posterior stabilization was performed using rods and screws 3 times, plate-screw fixation 25 times, and rods and screws at the thoracic level linked to plate-screw at the cervical level 2 times. Spinal cord compression of more than two levels was associated with 25 cases. In these 25 cases, spinal cord decompression was associated with reduction and stabilization. OUTCOME MEASURES: Clinical outcome using neurological scale of Frankel, radiological outcomes using computed tomographic (CT) scans and plain X-ray evaluations. METHODS: Follow-up periods ranged from 11 to 48 months, with an average of 18 months. Seven patients died as a result of cardiopulmonary insufficiency within 4 months postoperative. Twenty-eight CT scans with sagittal and frontal slides were examined to evaluate postoperative reduction and to control screw placement. RESULTS: The observed reductions were satisfactory in 27 cases. In one case, reduction was satisfactory in the sagittal plane but lateral translation persisted in the frontal plane. Two mechanical failures with delayed mobilization of implants occurred. Bony fusion was recorded in all cases on CT scan evaluation. Complete or partial neurological recovery was observed in only 10 of 14 patients. The initial neurological status of these 14 patients was Frankel B, C, or D. CONCLUSION: The surgical procedure was chosen according to the particularity of the anatomical region and the possibility of associated medullar decompression. Insertion of pedicle screws in the upper thoracic portion in T1, T2, and T3 requires a careful technique and knowledge of the posterior projection points of the pedicles and their orientation in space. The high rate of fusion observed in these patients justified posterior reduction and stabilization. The high death rate and the low rate of neurological recovery in this group of patients emphasizes the severe prognosis of unstable injuries of the cervicothoracic junction. Considering the few mechanical failures observed at the last examination, the choice of the posterior approach was appropriate as the one stage procedure. Plate synthesis is preferable in fractures that do not require extension of synthesis beyond T2, whereas screws and rods systems are more appropriate for superior thoracic injuries. Despite early diagnosis and surgical treatment, the presence of neurological or pulmonary lesions resulted in increased mortality of the operated patients.

[Adult spinal deformities]. / Les déviations rachidiennes de l'adulte.

Contrary to a commonly held notion, scoliosis, and especially lumbar and thoracolumbar scoliosis, can develop during adulthood. Its evolution is slow and insidious and involves both the anatomic aspect of the curve and the functional aspect (development or worsening of painful spinal or radicular symptoms and/or disequilibrium). This finding underlines the necessity of a regular and extended monitoring of all patients presenting with such a condition. In terms of anatomy, three elements, each of them having a very precise functional impact, may characterize the radiological evolution of those deformities: the development of a rotatory dislocation, stiffness of the primary curve, and especially the lumbo-sacral spine, and the progressive development of a thoracolumbar kyphosis. Three types of treatment are available: rehabilitation, orthopedic treatment and surgery. The first two can act efficiently on painful symptoms and/or disequilibrium but in no case can modify the evolving pattern of the deformity. Surgical treatment is useful in stopping the evolving processes, reequilibrating the trunk on the pelvis and controlling painful lumbar and sometimes radicular phenomenon. Therapeutic and especially surgical indications are complex and by no means can be limited to an angle threshold beyond which surgery is indicated. Those indications depend on the type, the severity and the potential or effective evolution of the primary and compensatory curves, as well as on the age, the functional impact of the deformity and the general medical condition of the patient.

Chondroblastoma of the lumbar spine. Report of two cases and review of the literature.

Chondroblastoma is a benign cartilaginous neoplasm that generally affects the appendicular skeleton. Twenty-six cases of spinal chondroblastoma have been reported in the past 50 years, only six of which were located in the lumbar region. The authors report two cases involving this exceptional location. In both patients, low-back pain, in the absence of radicular pain, was the presenting symptom. In both cases, plain radiography and computerized tomography scanning revealed an osteolytic lesion surrounded by marginal sclerosis. Magnetic resonance imaging allowed the authors to study the tumor's local extension. Examination of a percutaneous fluoroscopy-guided biopsy sample revealed the following typical histological features of chondroblastoma: chondroid tissue, focally alternating with cellular areas, and no nuclear atypia or pleomorphism. To reduce the risk of local recurrence, vertebrectomy and anterior-posterior fusion were performed in both cases. In one case, a structural lumbar scoliosis was corrected during the posterior procedure. There was no postoperative complication. No recurrence was observed during the 3- to 6-year follow-up period. The surgery-related results were deemed successful. Although exceptional, the diagnosis of chondroblastoma is possible in lesions involving the lumbar spine. Other spinal locations are described in the literature, and frequency of recurrence is stressed. A vertebrectomy is advised to reduce the risk of local recurrence.

Comparative study of postoperative and spontaneous pyogenic spondylodiscitis.

OBJECTIVES: Postoperative spondylodiscitis (POS) is poorly characterized, partly owing to its rarity. The aim of this prospective study was to compare the clinical, biological, bacteriological, and imaging features of postoperative and spontaneous spondylodiscitis (SS). METHODS: A multidisciplinary spondylodiscitis cohort follow-up study was conducted between February 1999 and June 2003 in a 500-bed teaching hospital. All patients hospitalized in internal medicine, orthopedic, and neurosurgery wards with a culture-proven diagnosis of pyogenic spondylodiscitis were included. Clinical and bacteriological data were collected. All patients underwent computed tomography and/or magnetic resonance imaging of the spine. RESULTS: Sixteen patients had SS and 7 patients had POS. Patients with POS tended to be younger (52 versus 69 years), with less frequent underlying diseases (29 versus 75%) and a more prolonged interval between symptom onset and diagnosis (16 versus 3.4 weeks) than patients with SS. Blood cultures were positive in 14 and 81% of cases in the POS and SS groups, respectively, and invasive diagnostic procedures were necessary in 86% of patients with POS and 19% of patients with SS ( P = 0.005). Staphylococci were the more frequent isolates in both groups but were more frequently coagulase-negative in POS patients than in patients with SS ( P = 0.01). Vertebral edema tended to be more frequent in POS and was located more posteriorly than in SS ( P = 0.023). CONCLUSIONS: POS is associated with specific clinical, microbiological, and imaging features possibly related to pathophysiologic characteristics. Knowledge of these characteristics should help reduce the current delay in the diagnosis of POS.

Radiographic analysis of the sagittal alignment and balance of the spine in asymptomatic subjects.

BACKGROUND: There is an increasing recognition of the clinical importance of the sagittal plane alignment of the spine. A prospective study of several radiographic parameters of the sagittal profile of the spine was conducted to determine the physiological values of these parameters, to calculate the variations of these parameters according to epidemiological and morphological data, and to study the relationships among all of these parameters. METHODS: Sagittal radiographs of the head, spine, and pelvis of 300 asymptomatic volunteers, made with the subject standing, were evaluated. The following parameters were measured: lumbar lordosis, thoracic kyphosis, T9 sagittal offset, sacral slope, pelvic incidence, pelvic tilt, intervertebral angulation, and vertebral wedging angle from T9 to S1. The radiographs were digitized, and all measurements were performed with use of a software program. Two different analyses, a descriptive analysis characterizing these parameters and a multivariate analysis, were performed in order to study the relationships among all of them. RESULTS: The mean values (and standard deviations) were 60 degrees 10 degrees for maximum lumbar lordosis, 41 degrees +/- 8.4 degrees for sacral slope, 13 degrees +/- 6 degrees for pelvic tilt, 55 degrees +/-10.6 degrees for pelvic incidence, and 10.3 degrees +/- 3.1 degrees for T9 sagittal offset. A strong correlation was found between the sacral slope and the pelvic incidence (r = 0.8); between maximum lumbar lordosis and sacral slope (r = 0.86); between pelvic incidence and pelvic tilt (r = 0.66); between maximum lumbar lordosis and pelvic incidence, pelvic tilt, and maximum thoracic kyphosis (r = 0.9); and, finally, between pelvic incidence and T9 sagittal offset, sacral slope, pelvic tilt, maximum lumbar lordosis, and thoracic kyphosis (r = 0.98). The T9 sagittal offset, reflecting the sagittal balance of the spine, was dependent on three separate factors: a linear combination of the pelvic incidence, maximum lumbar lordosis, and sacral slope; the pelvic tilt; and the thoracic kyphosis. CONCLUSIONS AND CLINICAL RELEVANCE: This description of the physiological spinal sagittal balance should serve as a baseline in the evaluation of pathological conditions associated with abnormal angular parameter values. Before a patient with spinal sagittal imbalance is treated, the reciprocal balance between various spinal angular parameters needs to be taken into account. The correlations between angular parameters may also be useful in calculating the corrections to be obtained during treatment.