Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Department of Operation Room, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Orthop Surg. 2024 Jul;16(7):1562-1570. doi: 10.1111/os.14085. Epub 2024 May 22.
Modic change (MC) is defined as abnormalities observed in the intervertebral disc subchondral and adjacent vertebral endplate subchondral bone changes. Most studies on MC were reported in the lumbar spine and associated with lower back pain. However, MC has been rarely reported in the cervical spine, let alone in those who underwent cervical disc replacement (CDR). This study aimed to focus on MC in the cervical spine and reveal clinical and radiological parameters, especially heterotopic ossification (HO), for patients who underwent CDR. Furthermore, we illustrated the association between MC and HO.
We retrospectively reviewed patients who underwent CDA from January 2008 to December 2019. The Japanese Orthopaedic Association (JOA), Neck Disability Index (NDI), and Visual Analog Scale (VAS) scores were used to evaluate the clinical outcomes. Radiological evaluations were used to conclude the cervical alignment (CL) and range of motion (ROM) of C2-7, functional spinal unit angle (FSUA), shell angle (SA), FSU height, and HO. Univariate and multivariate logistic regressions were performed to identify the risk factors for HO. The Kaplan-Meier (K-M) method was used to analyze potential risk factors, and multivariate Cox regression was used to identify independent risk factors.
A total of 139 patients were evaluated, with a mean follow-up time of 46.53 ± 26.60 months. Forty-nine patients were assigned to the MC group and 90 to the non-MC group. The incidence of MC was 35.3%, with type 2 being the most common. Clinical outcomes (JOA, NDI, VAS) showed no significant difference between the two groups. The differences in C2-7 ROM between the two groups were not significant, while the differences in SA ROM and FSUA ROM were significantly higher in the non-MC than in the MC group (p < 0.05). Besides, FSU height in MC group was significantly lower than that in non-MC group. Parameters concerning CL, including C2-7, FSUA, SA, were not significantly different between the two groups. The incidence of HO and high-grade HO, respectively, in the MC group was 83.7% and 30.6%, while that in the non-MC group was 53.3% and 2.2%, and such differences were significant (p < 0.05). Multivariate logistic regression analyses and Cox regression showed that MC and involved level were significantly associated with HO occurrence (p < 0.05). No implant migration and secondary surgery were observed.
MC mainly affected the incidence of HO. Preoperative MC was significantly associated with HO formation after CDR and should be identified as a potential risk factor for HO. Rigorous criteria for MC should be taken into consideration when selecting appropriate candidates for CDR.
Modic 改变（MC）被定义为观察到的椎间盘软骨下和相邻椎体终板软骨下骨变化的异常。大多数关于 MC 的研究都在腰椎中报道，并与下腰痛相关。然而，MC 在颈椎中很少报道，更不用说在接受颈椎间盘置换（CDR）的患者中了。本研究旨在关注颈椎中的 MC，并揭示临床和影像学参数，特别是异位骨化（HO），为接受 CDR 的患者。此外，我们还说明了 MC 与 HO 之间的关联。
我们回顾性分析了 2008 年 1 月至 2019 年 12 月期间接受 CDA 的患者。使用日本矫形协会（JOA）、颈部残疾指数（NDI）和视觉模拟评分（VAS）来评估临床结果。影像学评估用于总结 C2-7 的颈椎排列（CL）和活动范围（ROM）、功能脊柱单位角（FSUA）、壳角（SA）、FSU 高度和 HO。使用单变量和多变量逻辑回归来确定 HO 的危险因素。使用 Kaplan-Meier（K-M）方法分析潜在的危险因素，使用多变量 Cox 回归来识别独立的危险因素。
共评估了 139 名患者，平均随访时间为 46.53±26.60 个月。49 名患者被分配到 MC 组，90 名患者被分配到非 MC 组。MC 的发生率为 35.3%，其中 2 型最常见。两组的临床结果（JOA、NDI、VAS）无显著差异。两组之间 C2-7 ROM 的差异无显著性，而非 MC 组的 SA ROM 和 FSUA ROM 差异显著高于 MC 组（p<0.05）。此外，MC 组的 FSU 高度明显低于非 MC 组。MC 组和非 MC 组在 CL 参数方面，包括 C2-7、FSUA、SA，差异无显著性。MC 组的 HO 和高级 HO 的发生率分别为 83.7%和 30.6%，而非 MC 组的发生率分别为 53.3%和 2.2%，差异有显著性（p<0.05）。多变量逻辑回归分析和 Cox 回归显示，MC 和受累水平与 HO 的发生显著相关（p<0.05）。未观察到植入物迁移和二次手术。
MC 主要影响 HO 的发生率。术前 MC 与 CDR 后 HO 的形成显著相关，应被视为 HO 的潜在危险因素。在选择合适的 CDR 候选者时，应考虑 MC 的严格标准。
