Clinical and radiological evaluation of cervical disc arthroplasty with 5-year follow-up: a prospective study of 384 patients.

BACKGROUND: Cervical total disc replacement was developed to avoid known complications of cervical fusion. The purpose of this paper was to provide 5-year follow-up results of an ongoing prospective study after implantation of cervical disc prosthesis. METHODS: Three hundred and eighty-four patients were treated using Mobi-C cervical disc (Zimmer Biomet, Troyes, France) and included in a prospective multicentre study. Routine clinical and radiological examinations were reported preoperatively and postoperatively with up to 5-year follow-up. Complications and revision surgeries were also explored. RESULTS: Results at 5 years showed significant improvement in all clinical outcomes (NDI, VAS for arm and neck pain, SF-36 PCS and MCS). Motion at index level increased significantly from 6.0° preoperatively to 8.0°, and 72.1% of the implanted segments were still mobile (referring to threshold of ROM > 3°). Proximal and distal adjacent discs showed no significant change in average motion 5 years after surgery compared to baseline. Ossification resulting in complete fusion was observed in 16.4% of the implanted segments. Distal and proximal adjacent disc degeneration occurred in 42.2% and 39.1% of patients, respectively. Complications rate was 8.9%, and 1.5% of the patients had reoperation at the index level. Surgery rate of adjacent discs was 2.9%. An increased percentage of working patients and a decrease in medication consumption were observed. At 5 years, 93.3% patients were satisfied regarding the overall outcome. CONCLUSIONS: In this study, favourable 5-year follow-up clinical and radiological outcomes were observed with a low rate of adjacent level surgery. These slides can be retrieved under Electronic Supplementary Material.

Percutaneous surgery for thoraco-lumbar fractures in ankylosing spondylitis: Study of 31 patients.

BACKGROUND: The risk of vertebral fracture is increased 4-fold in patients with ankylosing spondylitis (AS). Diagnostic challenges and the vulnerability associated with AS combine to generate high morbidity and mortality rates. The objective of this study was to assess the outcome of percutaneous thoraco-lumbar fracture surgery in patients with AS, in terms of quality of life, fracture healing, and complications. HYPOTHESIS: Percutaneous surgery used to treat thoraco-lumbar fractures in patients with AS reliably provides fracture healing, preserves self-sufficiency, and minimises post-operative complications. METHODS: Two centres included 31 patients with AS who were managed by percutaneous surgery for thoraco-lumbar fractures in 2013-2015. The data were reviewed retrospectively, although admission data were collected prospectively. Clinical outcomes were assessed by comparing the values at baseline and last follow-up of three variables: the Parker score, the visual analogue scale (VAS) pain score, and the EuroQol five dimensions (EQ-5D) quality-of-life score. Computed tomography was performed 1 year after surgery to evaluate bone healing, screw position, and implant loosening. Intra- and post-operative complications were recorded. RESULTS: The 31 patients had a mean age at surgery of 75.1 years, a mean follow-up of 35.6 months, and a minimum follow-up of 12 months. Three patients died during follow-up. Mean hospital stay duration was 6 days. Cemented screw fixation was used in 18 patients. At last follow-up, all patients had recovered their self-sufficiency; the mean Parker score was 7.14, compared to 6.73 at baseline, the mean VAS pain score was 1.8, and the mean EQ-5D score decrease versus baseline was 0.07 (P=0.02). Bone healing was consistently achieved. Loosening of an uncemented pedicle screw was noted in 1 patient. Of the 228 screws implanted, 6 (2.6%) were improperly positioned, including 1 within the spinal canal in a patient free of neurological manifestations. Asymptomatic cement leakage was noted in 2 patients. DISCUSSION: Percutaneous fixation of thoraco-lumbar fractures in patients with AS is a reliable method that produces a high healing rate and allows prompt patient mobilisation with preservation of self-sufficiency. The post-operative complication rate is low. LEVEL OF EVIDENCE: IV, retrospective observational study.

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).

Comparison between total disc replacement and hybrid construct at two lumbar levels with minimum follow-up of two years.

INTRODUCTION: Lower back pain due to degenerative disc disease is a therapeutic challenge in young patients. Although arthrodesis is currently the gold standard for surgical treatment, improvement in total disc replacement techniques makes it possible to preserve segmental mobility with good results in one-level surgery. Nevertheless, the French National Health Authority does not recommend total disc replacement for multilevel surgery. Thus, hybrid constructs that combine one-level disc replacement with arthrodesis have been developed for multilevel indications. HYPOTHESIS: The outcome of two-level lumbar disc arthroplasty does not differ from hybrid constructs. METHODS: The clinical and radiographic outcomes of disc arthroplasty were compared to hybrid constructs for two-level degenerative disc disease in 72 patients after a continuous follow-up of at least 2 years. The patients were divided into two groups that were similar for the indication and type of implants. RESULTS: There was no statistical difference in pain relief (-3.9 points versus -3.5 points for lumbar VAS) or reduction in ODI (-29.5% versus -27.0%) between TDR and hybrid constructs, respectively. There was no statistical difference in range of motion at the level of arthroplasty (8.4° versus 7.6°) and no kinematic dysfunction was identified. The re-operation rate at two years for persistent lumbar pain was respectively 6.7% for two-level disc arthroplasty and 4.3% for hybrid constructs. The complication rate was 4.8% and 8.7% respectively. DISCUSSION: No difference was found in this comparison of two homogeneous series between two-level disc arthroplasty and hybrid constructs for the treatment of degenerative disc disease after two years of follow-up. Two-level disc arthroplasty may be an alternative for young patients depending on an evaluation of long-term results. LEVEL OF EVIDENCE: Cohort observational study level III.

Chondroblastoma of the thoracic spine: a rare location. Case report with radiologic-pathologic correlation.

Chondroblastoma is a rare benign cartilage neoplasm that arises from the appendicular skeleton in the vast majority of the cases (80%). Chondroblastoma of the spine is an even more rare condition (30 cases reported), and vertebral chondroblastomas, unlike chondroblastomas of the extremities, present with the appearance of an aggressive tumor on CT and MR imaging and occur at least a decade later. Even though vertebral chondroblastomas are very uncommon tumors, they should nonetheless be included in the differential diagnosis when encountered with an aggressive vertebral mass, and a histological confirmation should be performed. We present a case of chondroblastoma of the thoracic spine of a 27-year-old female for which detailed radiologic-pathologic correlation was obtained.

Cervical sagittal alignment in adult hyperkyphosis treated by posterior instrumentation and in situ bending.

BACKGROUND: In the normal adult spine, a link between thoracolumbar and cervical sagittal alignment exists, suggesting adaptive cervical positional changes allowing horizontal gaze. In patients with thoracic hyperkyphosis, cervical adaptation to sagittal global alignment might be different from healthy individuals. However, this relationship has not clearly been reported in hyperkyphotic deformity. PURPOSE: The purpose of this study was to identify cervical sagittal alignment types observed on radiographs in young adults with thoracic hyperkyphosis. The relationship between cervical and thoracolumbar alignment as well as the effect of posterior instrumentation and adaptive positional changes of the mobile cervical segment were retrospectively analyzed. PATIENTS AND METHODS: Twenty-three patients (32.7 years; 5-year follow-up) were included. Full spine radiographic measurements were: T1 slope, T1-T4 kyphosis, T4-T12 kyphosis, L1-S1 lordosis, pelvic incidence, pelvic tilt, sacral slope, SVA C7, SVA C2, lordosis between C0-C2, C2-C7, C2-C4 and C4-C7. A Bayesian model and Spearman correlation were used. RESULTS: Two alignment types existed: cervical lordosis (group A) and cervical kyphosis (group B). Preoperatively, T4-T12 kyphosis and L1-S1 lordosis were significantly higher in group A: 76.6° versus 59.4° and -72.8° versus -65.8° (probability of>5° difference P (ß>5)>0.95). Pelvic incidence was higher in group A (49.8° versus 44.2°) and C0-C2 lordosis in group B (-29.4° versus -21.6°). A significant correlation existed between: T4-T12 kyphosis and C2-C7 lordosis, L1-S1 lordosis and pelvic incidence, C2-C7 lordosis and T1 slope, C2-C7 lordosis and T1-T4 kyphosis. Postoperatively, T4-T12 kyphosis decreased by 33.1° P (ß>5)=0.9995), L1-S1 lordosis decreased by 17.7° (P (ß>5)=0.961), T1-T4 kyphosis increased by 14.1° (P (ß>5)=0.973). SVA C2 (translation) increased by 13.8mm. C0-C2 lordosis (head rotation) remained unchanged. Six patients changed cervical alignment. PJK occurred in 15 patients, unrelated to cervical alignment or proximal instrumentation level. DISCUSSION: Two cervical alignment types, lordotic or kyphotic, were observed thoracic hyperkyphosis patients. This alignment was mainly triggered by the amount of thoracic kyphosis and lumbar lordosis, linked to pelvic incidence. Moreover, the inclination of the C7-T1 junctional area plays a key role in the amount of cervical lordosis. The correction of T4-T12 kyphosis induced compensatory modifications at adjacent segments: T1-T4 kyphosis increase (PJK) and L1-S1 lordosis decrease. Global spino-pelvic alignment and head position did not change in the sagittal plane. The cervical spine tented to keep in its preoperative position in most patients. LEVEL OF EVIDENCE: Level IV.

Pullout characteristics of percutaneous pedicle screws with different cement augmentation methods in elderly spines: An in vitro biomechanical study.

BACKGROUND: Vertebroplasty prefilling or fenestrated pedicle screw augmentation can be used to enhance pullout resistance in elderly patients. It is not clear which method offers the most reliable fixation strength if axial pullout and a bending moment is applied. The purpose of this study is to validate a new in vitro model aimed to reproduce a cut out mechanism of lumbar pedicle screws, to compare fixation strength in elderly spines with different cement augmentation techniques and to analyze factors that might influence the failure pattern. MATERIALS AND METHODS: Six human specimens (82-100 years) were instrumented percutaneously at L2, L3 and L4 by non-augmented screws, vertebroplasty augmentation and fenestrated screws. Cement distribution (2 ml PMMA) was analyzed on CT. Vertebral endplates and the rod were oriented at 45° to the horizontal plane. The vertebral body was held by resin in a cylinder, linked to an unconstrained pivot, on which traction (10 N/s) was applied until rupture. Load-displacement curves were compared to simultaneous video recordings. RESULTS: Median pullout forces were 488.5 N (195-500) for non-augmented screws, 643.5 N (270-1050) for vertebroplasty augmentation and 943.5 N (750-1084) for fenestrated screws. Cement augmentation through fenestrated screws led to significantly higher rupture forces compared to non-augmented screws (P=0.0039). The pullout force after vertebroplasty was variable and linked to cement distribution. A cement bolus around the distal screw tip led to pullout forces similar to non-augmented screws. A proximal cement bolus, as it was observed in fenestrated screws, led to higher pullout resistance. This cement distribution led to vertebral body fractures prior to screw pullout. CONCLUSION: The experimental setup tended to reproduce a pullout mechanism observed on radiographs, combining axial pullout and a bending moment. Cement augmentation with fenestrated screws increased pullout resistance significantly, whereas the fixation strength with the vertebroplasty prefilling method was linked to the cement distribution.

Management of thoracolumbar spine fractures with neurologic disorder.

Thoracic and lumbar fractures represent approximately 50% of neurologic spinal trauma. They lead to paraplegia or cauda equina syndrome depending on the level injured. In the acute phase, the extension of spinal cord lesions should be limited by immediately treating secondary systemic injury factors. Quick recovery of hemodynamic stability, with mean arterial blood pressure>85 mm Hg, appears essential. There is no clinical evidence in favor of high-dose corticosteroid protocols. Their effect on neurologic recovery is unproven, whereas they lead to a higher rate of secondary septic and pulmonary complications. Incomplete deficits (ASIA B-D) require urgent surgery. There is no consensus with regard to complete paraplegia (ASIA A), but early surgery can enable neurologic recovery in some cases. The principle of surgical treatment is based on spinal cord decompression, instrumentation and fracture reduction. Early stabilization of the spine improves respiratory function and shortens the duration of mechanical ventilation and thus intensive care unit stay. Depending on the severity of associated lesions, early surgery within 48 hours is beneficial in polytrauma patients. Percutaneous instrumentation combined with mini-open posterior decompression stabilizes the spine, limiting approach-related morbidity.

A comparison of the simplified olecranon and digital methods of assessment of skeletal maturity during the pubertal growth spurt.

Assessment of skeletal age is important in children's orthopaedics. We compared two simplified methods used in the assessment of skeletal age. Both methods have been described previously with one based on the appearance of the epiphysis at the olecranon and the other on the digital epiphyses. We also investigated the influence of assessor experience on applying these two methods. Our investigation was based on the anteroposterior left hand and lateral elbow radiographs of 44 boys (mean: 14.4; 12.4 to 16.1 ) and 78 girls (mean: 13.0; 11.1 to14.9) obtained during the pubertal growth spurt. A total of nine observers examined the radiographs with the observers assigned to three groups based on their experience (experienced, intermediate and novice). These raters were required to determined skeletal ages twice at six-week intervals. The correlation between the two methods was determined per assessment and per observer groups. Interclass correlation coefficients (ICC) evaluated the reproducibility of the two methods. The overall correlation between the two methods was r = 0.83 for boys and r = 0.84 for girls. The correlation was equal between first and second assessment, and between the observer groups (r ≥ 0.82). There was an equally strong ICC for the assessment effect (ICC ≤ 0.4%) and observer effect (ICC ≤ 3%) for each method. There was no significant (p < 0.05) difference between the levels of experience. The two methods are equally reliable in assessing skeletal maturity. The olecranon method offers detailed information during the pubertal growth spurt, while the digital method is as accurate but less detailed, making it more useful after the pubertal growth spurt once the olecranon has ossified.

The effect of posterior non-fusion instrumentation on segmental shear loading of the lumbar spine.

BACKGROUND: Lumbar stenosis and facet osteoarthritis represent indications for decompression and instrumentation. It is unclear if degenerative spondylolisthesis grade I with a remaining disc height could be an indication for non-fusion instrumentation. The purpose of this study was to determine the influence of a mobile pedicle screw based device on lumbar segmental shear loading, thus simulating the condition of spondylolisthesis. MATERIALS AND METHODS: Six human cadaver specimens were tested in 3 configurations: intact L4-L5 segment, then facetectomy plus undercutting laminectomy, then instrumentation with lesion. A static axial compression of 400 N was applied to the lumbar segment and anterior displacements of L4 on L5 were measured for posterior-anterior shear forces from 0 to 200 N. The slope of the loading curve was assessed to determine shear stiffness. RESULTS: Homogenous load-displacement curves were obtained for all specimens. The average intact anterior displacement was 1.2 mm. After lesion, the displacement increased by 0.6mm compared to intact (P=0.032). The instrumentation decreased the displacement by 0.5 mm compared to lesion (P=0.046). The stiffness's were: 162 N/mm for intact, 106 N/mm for lesion, 148 N/mm for instrumentation. The difference was not significant between instrumented and intact segments (P=0.591). CONCLUSIONS: Facetectomy plus undercutting laminectomy decreases segmental shear stiffness and increases anterior translational L4-L5 displacement. Shear stiffness of the instrumented segment is higher with the device and anterior displacements under shear loading are similar to the intact spine. This condition could theoretically be interesting for the simulation of non-fusion instrumentation in degenerative spondylolisthesis.

Posterior surgery in high-grade spondylolisthesis.

INTRODUCTION: High-grade L5-S1 spondylolisthesis alters sagittal spinopelvic balance, which can cause low back pain and progressive neurologic disorder. The present study assessed spondylolisthesis reduction and maintenance over time with L4-S1 versus L5-S1 fusion using a lever-arm system and posterior fusion combined with lumbosacral graft. MATERIALS AND METHODS: Forty patients were operated on for symptomatic high-grade spondylolisthesis, 34 of whom had full pre- and post-operative radiological analysis, with a mean follow-up of 5.4years. There were 9 L5-S1 and 25 L4-S1 instrumentations. Analysis of spinopelvic and slipping parameters and the evolution of segmental lordosis compared results between L5-S1 and L4-S1 instrumentation. RESULTS: Mean Taillard spondylolisthesis index decreased from 64% to 37% (P=0.0001). Overall sagittal spinopelvic balance was not significantly changed. Overall L1-S1 and segmental L4-L5 lordosis were not affected by instrumentation. Mean L5-S1 segmental lordosis increased from 11° to 18°. There was loss of reduction from 19° to 14° with L5-S1 instrumentation, in contrast to maintained reduction with L4-S1 instrumentation (P=0.006). CONCLUSION: The lever-arm system provided anterior-posterior reduction of spondylolisthesis and corrected slippage. Postoperative change in overall sagittal spinopelvic balance was slight and constant. Posterior L4-S1 fusion provided better long-term control of L5-S1 lordosis reduction than the shorter L5-S1 fusion. Retrospective study of level IV.

Update on the surgical management of Pott's disease.

One-third of the world's population is infected with Mycobacterium tuberculosis. Data reported in 2011 indicate, for the first time, a decline in cases of tuberculosis, despite persistent inequalities across geographic areas and increasing rates of drug resistance. Osteo-articular tuberculosis affects the spine in half the cases. Pharmacotherapy must be combined with surgery in patients with spinal cord or nerve root compression, large abscesses, or marked anterior column osteolysis with kyphosis and instability. The quality of debridement and bony fusion is optimal when the anterior approach is used. Posterior fixation is the best means of achieving reduction followed by stable sagittal alignment over time. New treatment strategies combine conventional surgical methods, closed interventional radiology procedures for drainage and spinal cord decompression, and percutaneous fixation.

Fracture in ankylosing spondylitis after minor trauma: radiological pitfalls and treatment by percutaneous instrumentation. A case report.

Patients with ankylosing spondylitis may experience spinal fractures even after minor injuries. The diagnosis of non-dislocated spinal fracture is based on clinical symptoms and radiological findings. Difficulties in interpreting the imaging studies can result in considerable diagnostic delays. We describe the steps of the radiological diagnosis in a patient with a fracture of L2 that was not visible on standard lumbar spine radiographs. Magnetic resonance imaging (MRI) T2 STIR sequences allowed determining the location and showed signs of a recent fracture. Then, MRI T1 images and computed tomography provided a detailed evaluation of the fracture line. In patients with ankylosing spondylitis, fracture instability is common, making surgical treatment mandatory. Open surgery is associated with substantial rates of infection and implant loosening. Percutaneous instrumentation has not yet been evaluated for the treatment of spinal fractures in patients with ankylosing spondylitis. This minimally invasive surgical technique enables multilevel internal fixation and may constitute an interesting alternative to open surgery.

Preoperative phlebography in anterior L4-L5 disc approach. Clinical experience about 63 cases.

INTRODUCTION: The anterior approach of the L4-L5 disc requires a perfect knowledge of the venous anatomy. Some configurations make this approach hazardous. The purpose of this study is to classify configurations of the iliocava junction and the iliolumbar vein relative to L4-L5 and to analyze vascular complications. MATERIALS AND METHODS: The preoperative phlebographies of 63 patients (30 men, 33 women, mean age 42years) undergoing a L4-L5 disc replacement were reviewed. The height of the iliocava junction was calculated as a ratio of the distance between the discs L4-L5 and L5-S1. The position of the left iliac vein was classified into three thirds across the width of L5. The number of branches of the iliolumbar vein was noted. Surgical reports were reviewed for complications. RESULTS: The height of the iliocava junction was very high in six, high in 25, low in 26 and very low in six patients. The position of the left iliac vein was medial in 20, intermediate in 28 and lateral in 15 patients. The iliolumbar vein had one branch in 37, two in 20, three in three patients. It was not visualized in three cases. Variants of the venous anatomy included eight duplications of the left iliac vein, four wide diameters and one iliolumbar vein network pattern. Intraoperatively, three lacerations of iliolumbar veins occurred. CONCLUSION: The iliocava anatomy is very variable: the safety of an anterior approach to the L4-L5 disc depends on it. The information of preoperative phlebography can help to plan a more accessible antero-lateral approach or to switch on a posterior fusion if the anatomical situation is deemed too dangerous, such as duplicated left iliac veins. LEVEL OF EVIDENCE: Level IV. Diagnostic study.

Is preoperative embolization a prerequisite for spinal metastases surgical management?

BACKGROUND: Preoperative embolization decreases the intraoperative risk of hemorrhage in spinal decompression surgery of hypervascular metastases such as renal cell carcinoma. There is no consensus concerning embolization in other metastases. The purpose of this study was to compare the intraoperative amount of blood loss in embolized versus non-embolized patients, seeking for differences depending on the primary tumor and the extent of surgery. PATIENTS AND METHODS: Ninety-three patients, average age 60.5 years, were operated. The origins of metastases were: 28 breast cancer (30.1%), 19 pulmonary carcinoma (20.4%), 16 renal cell carcinoma (17.2%), 30 other cancers (32.3%). Surgical procedures were: 52 thoracolumbar laminectomies with instrumentation, 29 thoracolumbar corpectomies or vertebrectomies, 12 cervical corpectomies. A preoperative microsphere embolization was performed in 35 patients. Blood loss was evaluated by: blood volume in surgical aspiration devices, number of transfused packed red blood cells units and hemoglobin variation during surgery. RESULTS: Renal metastases were systematically embolized. In the breast group, there was no significant difference (P>0.05) in blood loss between embolization versus non-embolization. In the pulmonary group and in other metastases, no difference was found either. The extent of surgery (corpectomy/vertebrectomy versus thoracolumbar instrumentation and cervical corpectomy) increased bleeding: breast 1775ml versus 778ml and 600ml respectively (P=0.048), pulmonary 2500ml versus 430ml and 180ml (P=0.020), renal 3346ml versus 1175ml and 780ml (P=0.036) and others 1550ml versus 474ml and 400ml (P=0.020). CONCLUSIONS: Embolization decreases the risk of hemorrhage in highly vascularized metastases such as renal cell carcinoma. A benefit of embolization was not found for metastases of breast or pulmonary tumors. As far as other metastases, thyroid carcinoma should be analyzed on a greater cohort. The extent of surgery remains an important risk factor for intraoperative bleeding. A preoperative angiogram should be carried out in all types of metastases prior to a thoracolumbar corpectomy or vertebrectomy to perform an embolization if the tumor is hypervascular. LEVEL OF EVIDENCE: Level IV, retrospective study.

Should post-traumatic thoracolumbar Frankel A paraplegia be operated as an emergency? Report of three cases and review of the literature.

Spinal cord injury is an important contributing factor to morbidity. The thoracolumbar junction is a highly vulnerable axial region due to the biomechanical stresses and the risk of conus medullaris injuries in some cases. In the event of an incomplete neurological injury and if the patient's condition is stable, emergency surgical treatment should be considered. Yet, no clear consensus has emerged regarding the treatment modalities of complete injuries but surgical management is advocated to maximize neurological recovery and reduce the risk of decubitus ulcer formation. We report on the cases of three patients with L1 Frankel A paraplegia resulting from injury to the conus medullaris, treated within the first 6 hours from injury and demonstrating a very satisfactory neurological recovery since independent walking could be resumed at 2.5 years follow-up. Persistent urinary sphincter dysfunctions were observed in two of these patients. Early surgical management appears as an important predictive factor for neurological recovery in conus medullaris injuries. We believe that delayed surgical management in patients with complete paraplegia could be an inappropriate treatment option, which should be further studied.

Focus on perioperative management of anticoagulants and antiplatelet agents in spine surgery.

UNLABELLED: Perioperative management of anticoagulants and antiplatelet agents is based on a compromise between the risk of hemorrhage induced by maintaining (or substituting for) them and the risk of thrombosis if they are discontinued. The hemorrhage risk in major spinal surgery is clear (50-81% incidence of transfusion), and the incidence of postoperative symptomatic spinal hematoma varies between 0.4% and 0.2% depending on whether low-molecular-weight heparin (LMWH) is prescribed postoperatively. The French Health Authority, in 2008, published guidelines on the management of patients treated with vitamin K antagonists. Treatment may be stopped without preoperative replacement in certain cases of atrial fibrillation or venous thromboembolic disease; otherwise, preoperative replacement by curative dose unfractionated heparin (UFH) or LMWH is recommended, with withdrawal early enough to avoid peroperative bleeding. Postoperative care should take account of hemorrhagic risk following surgery. The management of patients treated with antiplatelets is delicate, as maintenance is preferable in most of the situations in which they are prescribed (bare or active stenting, or secondary prevention of myocardial infarction, stroke or peripheral ischemia), although they are liable to increase the risk of perioperative hemorrhage, especially when associated to antithrombotic prophylaxis. If surgery cannot be performed under treatment continuation, the interruption should be as short as possible. New guidelines are presently being drawn up under the auspices of the French Health Authority. In both types of treatment, the strategy should be jointly determined by surgeon, anesthesiologist and cardiologist, to optimize individualized care taking account of each party's requirements, with the patient in the central role. The selected strategy should be clearly stated in the patient's file. LEVEL OF EVIDENCE: V.

[Dynamic instrumentation of the lumbar spine. Clinical and biomechanical analysis of success factors]. / Dynamische Versorgung der Lendenwirbelsäule : Klinische und biomechanische Analyse der Erfolgsfaktoren.

Total disc replacement and posterior dynamic stabilization represent alternatives to lumbar spinal fusion which should reduce the risk of adjacent segment degeneration. Disc replacement is indicated for pure discopathy without facet joint degeneration. Spinopelvic balance influences the implant's biomechanics. Therefore pelvic incidence, sacral slope, segmental lordosis and the mean axis of rotation need to be considered. Dynamic stabilization is indicated in moderate discopathy and facet joint degeneration, in degenerative spondylolisthesis grade I with a hypermobile segment and in dynamic lumbar stenosis. The combination of caudal fusion and cranial dynamic stabilization allows a better maintenance of lordosis with multiple level instrumentation and prevents adjacent segment degeneration. If pelvic incidence and sacral slope are high, L5-S1 should be fused because of elevated shear forces.