Objective: To evaluate the influence of carpentry of Bryan disc, including artificial disc coverage ratio and shell angular, on long-term efficacy and complications cervical artificial disc replacement. Methods: To retrospectively analyze the clinical data of 86 patients who underwent Bryan disc replacement in Beijing Jishuitan Hospital between 2003 and 2007 (including 101 operated segments). All the patients were followed-up for more than 10 years. Mean age of the patients was (53±9) years, including 51 males and 35 females, and 71 patients underwent single-level and 15 patients underwent two-level artificial disc replacement. Artificial disc coverage ratio and shell angular were measured on postoperative natural X-ray. According to the perfectness of carpentry including 2 parameters (postoperative shell kyphosis and artificial disc coverage ratio smaller than 95%), operated levels were divided into 2 groups: 43 levels in the optimal group and 58 levels in the suboptimal group. Radiographic indexes were evaluated preoperatively and at the last follow-up, included the segmental range of motion(ROM), segmental COBB's angle, the occurrence of segmental mobility lost, segmental kyphosis and the high grade paravertebral ossification(PO). Clinical indexes including Japanese Orthopaedic Association (JOA) score, neck disability index (NDI) and Odom's criteria were evaluated preoperatively and at the last follow-up. The improvement of JOA score, NDI% decline and the satisfaction rate of Odom's criteria were calculated too. The continuous data were analyzed by independent sample t test. The grading data were analyzed by Mann-Whitney test. Results: The mean age of the optimal group was (52±7) years, including 23 males and 14 females; the mean age of the suboptimal group was (54±10) years, including 28 males and 21 females.The baseline data of two groups were comparable. There were significant differences in the segmental ROM, the segmental COBB's angle, the occurrence of segmental mobility lost, segmental kyphosis and the high grade PO between the two groups at the last follow-up (t=5.608, 3.812, χ(2)=15.097, 18.334, 27.141, all P<0.05). The improvement rate of JOA score was 69%±39% and 66%±44%, the NDI% decline was 14%±8% and 11%±8%, the satisfaction rate of Odom's criteria was 97.3% and 83.7% in optimal group and suboptimal group, respectively; there was no significant difference in the up-mentioned indexes between the two groups(t=0.307, 1.483, Z=0.989, all P>0.05). Conclusion: The carpentry of prosthesis will influence the occurrence of segmental mobility lost, segmental kyphosis, and high grade PO with cervical artificial disc replacement in the long run. It is suggested that the artificial disc coverage smaller than 95% and the shell kyphosis should be avoided.
目的： 探讨Bryan人工间盘覆盖比和端板角等假体安置因素对颈椎人工间盘置换术后远期临床疗效和并发症的影响。 方法： 回顾性分析北京积水潭医院2003年12月至2007年12月86例患者共101个节段因颈椎退行性疾病行Bryan人工间盘置换术且随访10年以上的临床资料。平均年龄(54±9)岁，其中男51例，女35例，71例为单节段置换，15例为双节段置换。术后中立位X线片上测量人工间盘覆盖比和人工间盘端板角。依据人工间盘覆盖比是否>95%和人工间盘端板角是否后凸将患者分为2组：手术理想组43个节段和手术欠佳组58个节段。分别于术前和末次随访时评估患者影像学指标包括：手术节段活动度、手术节段COBB角、椎旁骨化分级和是否出现手术节段活动度丧失、局部后凸和高等级椎旁骨化。分别于术前和末次随访时评估患者临床功能指标包括：日本骨科协会评分(JOA)、颈椎功能障碍指数(NDI)及Odom′s标准并计算JOA改善率、NDI%下降情况和Odom′s优良率。连续变量数据使用独立样本t检验进行分析，分级变量数据使用Mann－Whitney检验进行分析。 结果： 手术理想组患者37例，男23例，女14例，年龄(52±8)岁；手术欠佳组患者49例，男28例，女21例，年龄(55±10)岁。两组基线资料具有可比性。两组患者末次随访时手术节段活动度、手术节段COBB角、活动度丧失率、局部后凸及高等级PO的发生率均存在显著性差异(t＝5.608、3.812，χ(2)＝15.097、18.334、27.141，均P<0.05)。手术理想组和手术欠佳组患者JOA改善率分别为69%±39%和66%±44%，NDI%分别下降14%±8%和11%±8%，Odom′s标准优良率分别为97.3%和83.7%，两组差异均无统计学意义(t＝0.307、1.483，Z＝0.989，均P>0.05)。 结论： 假体安置因素会影响人工间盘置换术后远期手术节段活动度、局部后凸和高等级PO的发生。术中操作时，应尽量避免出现人工间盘覆盖比<95%与人工间盘端板角后凸的发生。.
Keywords: Bryan disc; Cervical artificial disc replacement; Long-term fellow-up; Paravertebral ossification; Segmental kyphosis.