颈椎退行性疾病Bryan间盘置换术后椎旁骨化影响因素分析

Influencing factors for paravertebral ossification in patients with cervical degenerative disease after Bryan artificial disc replacement

目的探讨颈椎退行性疾病患者行Bryan间盘置换后节段活动度、假体偏移程度及倾斜角度与椎旁骨化(PO)的关系。方法选取颈椎退行性疾病行Bryan间盘置换患者76例(手术节段90个),平均随访时间均超过10年。分别于术前、术后3个月、末次随访时拍射X线光片,测量置换节段活动度;末次随访时在冠状位重建CT图像上测量假体偏移程度及假体的倾斜角度,并采用Mc Afee分型判断末次随访时PO分级。回顾性分析末次随访时发生4级PO的影响因素,假体偏移程度及倾斜角度与PO分级及节段活动度的关系。结果术前、术后3个月、末次随访时置换节段活动度分别为9.2°±4.7°、8.2°±4.8°、8.7±5.1°,各时间段比较P均>0.05;末次随访时节段活动度与术后3个月时节段活动度呈正相关(r=0.572,P<0.01)。末次随访时冠状位假体偏移程度的中位数为0.61(0~7.08)mm,假体倾斜角度的中位数为0.84°(0.01°~9.79°);末次随访时假体偏移程度与末次随访置换节段活动度呈负相关(r=-0.379,P=0.001)。末次随访时发生4级PO共17个节段(15例)、0~3级PO共73个节段(63例),PO 4级患者手术时年龄大于0~3级患者(P<0.05),术后3个月及随访时置换节段活动度均低于0~3级患者(P均<0.01)。与冠状位假体偏移程度≤3 mm患者比较,>3 mm患者置换节段末次随访PO分级更高、节段活动度更低(P均<0.01)。与冠状位假体倾斜角度≤5°患者比较,>5°患者置换节段末次随访PO分级更高、节段活动度更低(P均<0.05)。结论颈椎人工间盘置换术术后患者保持早期置换节段活动度,可有效避免4级PO的发生;假体安放偏离中心或在冠状位发生倾斜均会造成远期随访时PO分级更高,并对远期活动度产生影响,尤其避免偏移程度超过3 mm或倾斜程度超过5°。

Objective To discuss the relationship of segmental range of motion （ ROM） , implant deviation and im-plant tilt with the paravertebral ossification （ PO） in patients with cervical degenerative disease after Bryan cervical artificial disc replacement （ CADR） .Methods A total of 90 Bryan discs which were implanted into 76 patients with cervical de-generative disease were retrospectively analyzed .The average follow-up time was more than 10 years.The segmental ROM was measured by X-ray at the preoperation , 3 months′follow-up and the last follow-up.We used the coronal reconstruction CT to evaluate the implant deviation and implant tilt at the last follow-up, and determined the grades of PO by McAfee at the last follow-up.We retrospectively analyzed the influence factors of grade 4 PO as well as the relationship of segmental ROM, implant deviation and implant tilt with the grade of PO .Results The segmental ROM at preoperation , 3 months′follow-up and the last follow-up was 9.2°±4.7°, 8.2°±4.8°and 8.7 ±5.1°（all P〉0.05）.The segmental ROM at 3 months′follow-up and the last follow-up was positively correlated （r=0.572, P〈0.01）.The median and interquartile range of implant deviation was 0.61 （0-7.08） mm and 0.84 （0.01-9.79）°.The implant tilt was negatively correlated with segmental ROM at the last follow-up （r=-0.379, P=0.001）.At the last follow-up there were 17 segments （15 pa-tients） with grade 4 PO and 73 segments （63 patients） with grade 0-3 PO.Patients who had grade 4 PO were older than the patients with the grade 0-3 PO （P〈0.05）.Patients with the grade 4 PO had less segmental ROM than that of patients with the grade 0-3 PO at the 3 months′and last follow-up （all P〈0.01）.The segment whose implant deviation was greater than 3 mm would have a higher PO grade （P〈0.01）, and less ROM at the last follow-up （all P〈0.01）.The segment whose implant tilt was greater than 5°would have a higher PO grade （P〈0.01）, and less ROM at the last follow-up （P〈0.05）.Conclusions Maintaining the segmental ROM after the early stage of CADR can avoid the grade 4 PO.The im-plant deviation or implant tilt will cause the higher grade of PO in the long-term follow-up and will influence the long term ROM, and especially we should avoid the implant deviation more than 3 mm or implant tilt more than 5°.