Rousseau Marc-Antoine, Lazennec Jean-Yves, Saillant Gérard
Department of Orthopaedic Surgery, La Pitié-Salpétrière Hospital, University of Paris VI, France.
J Spinal Disord Tech. 2007 Jun;20(4):278-81. doi: 10.1097/01.bsd.0000211284.14143.63.
Usual interbody cages at the lumbar spine are made of titanium or carbon fiber-polyetheretherketone (PEEK). Pure PEEK cages have more recently been proposed for its lower elasticity modulus. The goal of our study was to investigate a series of patients with circumferential fixation using anterior PEEK cages for degenerative lumbar spine disorders with a specific interest in the local lordosis. Fifty-seven consecutive patients aged 54.6 years (29 to 75) were reviewed. The level of arthrodesis varied from L2L3 to L5S1. The clinical status and the radiologic variations in local lordosis at the level of arthrodesis were measured. Decrease in lordosis at follow-up was tested in a multivariate analysis regarding age, obesity, spinal level, bone graft amount, type of posterior instrumentation, postoperative lordosis increase, and cage height. The average follow-up was 5.7 years (4 to 8). Clinical outcomes were excellent or good in 49 cases. Fusion was definite in 56 cases. Although 47 patients had no change in lordosis after surgery, 10 cases showed lordosis increase (8.2 degrees; 5 to 12). At follow-up, local lordosis decreased in 13 cases (5.6 degrees; 4 to 8). The linear model was significant (P<0.001; R=0.590) showing that loss in lordosis was related with postoperative lordosis increase (P=0.01), cage height (P<0.001), posterior instrumentation rigidity (P=0.026), age (P=0.047), and low level (P=0.013). Lumbar circumferential arthrodesis using PEEK cages provided good clinical results and fusion rate. However, lordosis correction was not maintained at follow-up, especially at lower levels, using high cages, in older patients, and when associated with a rigid primary posterior instrumentation. Regarding the last point, this is likely that the order of the instrumentation (posterior first, then anterior) played a role in the loss of lordosis in case of rigid posterior fixation.
腰椎常用的椎间融合器由钛或碳纤维聚醚醚酮(PEEK)制成。最近有人提出使用纯PEEK融合器,因其弹性模量较低。我们研究的目的是调查一系列使用前路PEEK融合器进行环形固定治疗退行性腰椎疾病的患者,特别关注局部前凸。回顾了57例连续患者,年龄54.6岁(29至75岁)。融合节段从L2L3到L5S1不等。测量了融合节段的临床状况和局部前凸的影像学变化。在多因素分析中,对年龄、肥胖、脊柱节段、植骨量、后路内固定类型、术后前凸增加情况和融合器高度进行了测试,以检验随访时前凸的降低情况。平均随访时间为5.7年(4至8年)。49例患者的临床结果为优或良。56例患者融合明确。虽然47例患者术后前凸无变化,但10例患者前凸增加(8.2度;5至12度)。随访时,13例患者局部前凸降低(5.6度;4至8度)。线性模型具有显著性(P<0.001;R=0.590),表明前凸丢失与术后前凸增加(P=0.01)、融合器高度(P<0.001)、后路内固定刚度(P=0.026)、年龄(P=0.047)和低位节段(P=0.013)有关。使用PEEK融合器进行腰椎环形融合术可提供良好的临床效果和融合率。然而,随访时前凸矫正未得到维持,尤其是在低位节段,使用高融合器、老年患者以及与坚固的初次后路内固定相关时。关于最后一点,在坚固的后路固定情况下,内固定顺序(先后路,然后前路)可能在前凸丢失中起作用。