颈前路钛网植骨融合术后钛网沉陷的原因探讨

目的：探讨颈前路钛网植骨融合术后钛网发生沉陷的原因及其对临床疗效的影响，并提出相应对策。方法：回顾性分析在我院行颈前路钛网植骨融合术的各类颈椎疾患患者179例，观察患者骨密度、钛网修剪及放置情况、终板处理情况、钢板类型、植骨及椎体撑开情况等。采用日本骨科学会（JOA）评分法评价神经功能的变化。结果：有17例患者发生钛网沉陷，沉陷的原因主要为骨密度下降、钛网修剪放置不当、术中过度撑开、终板刮除过多、使用非限制性钢板、采用同种异体骨植骨、螺钉进钉深度过浅和方向不当、钢板放置位置偏斜等。术后所有患者JOA评分比术前平均增加3．5分（P〈0．01）。162例未发生钛网下沉患者术后3个月和6个月的JOA评分比术前平均增加4．4分和4．7分：发生钛网下沉患者中。6例有临床症状者沉陷时和沉陷3个月时的JOA评分为2．9分和3．8分．7例无临床表现者为3．3分和3．9分．4例有临床症状行翻修手术者翻修术后1周和3个月时JOA评分比翻修前提高3．3分和3．7分。结论：颈前路钛网植骨融合术后可发生钛网下沉，骨质疏松患者应该避免使用钛网。手术时应尽可能增加钛网与终板接触面积，多保留相邻终板，选用限制性钢板，尽量选择自体骨植骨，避免椎间过度撑开等。防止术后钛网沉陷。

Subsidence of titanium mesh after anterior cervical corpectomy with titanium mesh and bone graft fusion

Objective:To explore the reasons of subsidence of the titanium mesh after anterior cervical corpectomy and bone graft fusion with titanium mesh,and its clinical effects and suggestions.Method:179 cases with cervical diseases in our hospital undergoing the surgery of anterior cervical corpectomy with titanium mesh and bone graft fusion were retrospectively reviewed.The bone mineral density,the titanium mesh trimming and placement,the management of endplate,plate types,bone graft and overdistraction of vertebral body and so on were observed.JOA score was used to evaluate the changes of the neurological function as well as the clinical outcome.Result:Titanium meshes have good performances in 162 cases,yet 17 cases were evidenced subsidence after operation.The reasons for titanium mesh subsidence included the bone density decrease,improper trimming and placement of titanium mesh,overdistraction,over-curette of the endplate,choosing more restricted plate,heterograft,incorrect length and direction of screw and the oblique placement of the plate after corpectomy.The JOA scores of all the patients improved 3.5 point in average.Of the 162 cases without mesh subsidence,the JOA scroes of 3 and 6 months postoperation increased 4.4 and 4.7 respectively compared with preoperation.Of the cases with mesk subsidence,the JOA scores of 6 cases with clinical presentations was 2.9 preoperatively and 3.8 postoperatively,and the JOA scores of 7 cases without clinical presentations was 3.3 and 3.9 respectively.The JOA scores of 4 cases with clinical presentations undergoing the revisional surgery increased 3.3 at 1rd week and 3.7 at 3rd month respectively compared with prerevisional.Conclusion:To prevent subsidence of the titanium mesh patients with osteoporosis should avoid this surgery,the touch area of the titanium mesh with endplate should been larged,more adjacent endplate should be kept,choosing restrictive plate system and autograft,and moderate distraction shoud be adopted.