Objective: To investigate the correlation between the severity of uncovertebral joints degeneration and heterotopic ossification (HO) after single-level artificial cervical disc replacement (ACDR). Methods: From January 2005 to January 2016, 70 patients who had undergone single-level ACDR in Peking University Third Hospital and had at least 5 years follow-up were included in this study. There were 35 males and 35 females with an average age of (42±8) years (range, 25-62 years). Cervical spine A-P X-rays were taken to assess the degeneration of uncovertebral joints and lateral X-rays were taken to assess the degeneration of intervertebral space. Cervical spine lateral and the flexion-extension X-rays at 5 years follow up were taken to assess HO. Degeneration of uncovertebral joints were evaluated by the classification system set-up in Peking University Third Hospital. Kellgren&Lawrence grading system was used to evaluate the degeneration of intervertebral space. HO was evaluated by the McAfee grading standards. The data were collected before surgery and at 5-years follow-up, then the correlation between degeneration of uncovertebral joints, degeneration of intervertebral space and HO was analyzed with Spearman non-parametric test. Results: The average follow-up time of 70 patients was (62.7±4.8) years (range, 52-74 months). There was a significant positive correlation between preoperative uncovertebral joints degeneration and HO after ACDR (r=0.585, P<0.01). There was a significant positive correlation between preoperative intervertebral space degeneration and HO (r=0.557, P<0.01). There was a significant positive correlation between preoperative intervertebral space degeneration and preoperative uncovertebral joints degeneration (r=0.727, P<0.01). Conclusion: There is a significant positive correlation between preoperative uncovertebral joints degeneration and HO after ACDR.
目的： 探讨术前钩椎关节的退变程度与颈椎人工间盘置换术（ACDR）后异位骨化的严重程度的相关性。 方法： 纳入北京大学第三医院2005年1月至2016年1月接受ACDR并获得最低5年随访的患者70例，其中男35例，女35例；年龄25~62（42±8）岁。术前颈椎正位X线片用于评价钩椎关节退变情况，侧位X线片用于评价椎间隙退变情况。术后5年随访时侧位和过伸过屈侧位X线片，评价异位骨化情况。采用我们提出的分级方法评价术前钩椎关节退变情况，采用Kellgren&Lawrence分级和McAfee分级评价椎间隙退变情况和异位骨化情况。统计不同患者术前术后情况并进行相关系数检验。根据假体的不同类型和术后异位骨化发生部位，明确二者之间有无关系。 结果： 70例患者的随访时间为52~74（62.7±4.8）个月，手术方式均为单节段颈椎人工椎间盘置换。术前钩椎关节退变程度与术后异位骨化严重程度具有显著的正相关性，相关系数r=0.585（P<0.01）。术前Kellgren&Lawrence椎间隙退变与术后异位骨化的严重程度具有显著的正相关性，相关系数r=0.557（P<0.01）。术前Kellgren&Lawrence椎间隙退变分级和术前钩椎关节退变分级具有显著的正相关性，相关系数r=0.727（P<0.01）。 结论： 术前钩椎关节退变程度与术后异位骨化的严重程度具有正相关性。.
Keywords: Cervical artificial disc replacement; Cervical vertebrae; Degeneration of intervertebral space; Degeneration of uncovertebral joints; Heterotopic ossification.