同种异体椎间盘移植治疗颈椎间盘疾患的安全性及疗效

An over 10-year outcome of intervertebral disc allograft for degenerative cervical spine disease

目的：探讨同种异体颈椎间盘移植的安全性与可行性，分析多中心同种异体椎间盘移植治疗颈椎间盘疾患的临床疗效。方法：前瞻性、非双盲观察同种异体颈椎间盘移植治疗颈椎间盘疾患的临床疗效。全组共27例，男22例，女5例；年龄37~58岁，平均45岁。所有病例均为颈椎退行性疾病患者，其中脊髓型颈椎病20例，颈椎间盘突出症7例。均经颈前入路手术行同种异体椎间盘移植，不使用任何内固定。术后常规行血常规等化验检查，定期复查颈椎X线片、CT及MRI，分别观察椎间盘愈合情况，测量移植椎间盘信号灰度值及钆喷酸葡胺对移植椎间盘的增强成像情况。临床功能分别采用疼痛VAS评分、颈椎功能障碍指数（NDI）及JOA评分系统评估，全身情况采用SF-36功能量表评估。结果：平均手术时间1.5h，平均失血量55ml。术后血常规等检查均正常，无感染、脱位等并发症。伤口均一期愈合。术后各随访时间点患者颈肩及上肢疼痛VAS评分、NDI、JOA评分、SF-36均较术前显著性改善（P〈0.05）。随着随访时间延长，移植椎间盘高度有下降趋势，随访120个月的患者为4.08±1.75mm，是术后即刻高度的76%；屈伸活动度与术后即刻比较有增加趋势，随访120个月的患者为9.91°±4.65°；移植椎间盘MRI信号灰度值术后即刻为0.39±0.08，随访120个月的患者为0.15±0.07（P〈0.05）。钆喷酸葡胺MRI增强扫描6h椎间盘灰度值达0.62±0.04，与增强前（0.28±0.06）比较有显著性差异（P〈0.05）。移植椎间盘的旋转活动中心术后逐渐向椎间盘后下方移动，与术前比较在X、Y轴上均有显著性变化（P〈0.05）。结论：同种异体椎间盘移植的临床应用是安全和可行的，远期虽有退变但仍能保持良好椎间高度与活动度，椎间盘营养通道得以重建，旋转活动中心趋向生理中心。是颈椎间盘退行性疾病外科治疗的一种新途径。

Objectives： To address the multi-center clinical and radiographic outcome of intervertebral disc allograft in patients with over 10-year follow-up as well as its safety and reliability. Methods： A prospective cohort study including 27 patients with a mean age of 45 years old with suffering from cervical degenerative disc disease and undergoing transplantation of fresh-frozen composite disc allograft was performed. Static and dynamic radiographs were performed to assess graft-complex integrity, segmental stability and mobility. Japanese Orthopedic Association（JOA） score was used to evaluate neurofunction. NDI, VAS and SF-36 were also utilized. Prospective data were collected at pre-operation, post-operation, 1, 3, 6, 12, 60 and 120 months after surgery. Serial MRI scans were performed before surgery and at 3, 6, 12 months and the final follow-up. As the indexes of degeneration, gray scales of discs based on MRI were measured by a modified Schneiderman′s score. Diffusion of nutrition across the endplate was assessed by using Gadolinium enhancement MRI. Adjacent discs were used as the control. Center of rotation（COR） in the allografted disc was also measured. Results： Neurological status improved in all patients and maintained throughout follow-up. Clinically, good and excellent outcomes were noted in 20 patients respectively. There was no complaint of neck or arm pain in the long time follow-up. Bony unions were noted between the grafted disc endplates and recipient vertebral bodies. Cervical lordosis was maintained in most of the cases. Spontaneous fusion of the grafted disc was noted in 1 patient as previously reported. All grafted discs presented a higher gray scale after transplantation. Compared with the control, 20 grafted discs showed a similar gray scale value, whereas another seven discs showed a relatively lower value. From T1-weighted imaging, contrast enhancement displayed gadolinium diffusion into the center of the disc in both the normal and grafted segments（P〈0.05）. Conclusions： The prospective and long-term follow-up outcomes demonstrate that cervical disc allograft is safe and effective. Despite of mild disc degeneration, there is still nutrition diffusion across the endplates, as well as the recovery of physiological rotation center, which is an alternative to conventional surgical intervention for degenerative cervical spine disease.