腰椎单节段固定融合术后上位相邻节段退变及其与临床疗效的关系

Analysis of cranial adjacent segment degeneration after single-segment instrumented fusion:clinical results and risk factors

目的:探讨腰椎单节段固定融合术后上位相邻节段退变及其与临床效果的关系,分析退变的相关因素。方法:回顾性分析2004年10月～2009年5月采用后路单节段椎弓根螺钉固定并椎体间cage植骨融合术治疗的49例L4/5退变性失稳患者,男22例,女27例,年龄28～72岁(平均53.4岁)。所有患者术前均行骨密度检测。在X线片上测量固定节段及其上位相邻节段椎间盘高度、椎间隙动态角度变化、椎体滑移距离以及固定节段和腰椎前凸角、腰骶关节角,并通过JOA评分及腰功能障碍指数(ODI)评价临床效果。根据末次随访时上位相邻节段有无影像学退变,分为退变组与非退变组,比较两组间临床效果及影像学测量结果。结果:随访时间为13～52个月,平均为29.3个月,所有患者术后均无神经损害加重症状。末次随访时11例患者(22%)出现上位相邻节段影像学退变。两组患者手术时的平均年龄有显著性差异(P<0.05);术前骨密度、腰椎前凸角、腰骶关节角、L4/5前凸角和椎体间滑移距离均无显著性差异(P>0.05);末次随访时L3/4椎体间滑移距离、L3/4椎间盘高度以及椎间隙动态成角变化值均存在显著性差异(P<0.05),ODI和JOA评分改善率无显著性差异(P>0.05)。患者年龄与末次随访时固定上位相邻节段椎间盘高度、椎间隙动态成角、椎体间滑移距离变化值存在正相关性,相关系数分别为0.353、0.521、0.472,余测量指标与固定上位相邻节段影像学指标变化均无显著相关性。结论:单节段腰椎固定融合术后上位相邻节段影像学退变与临床效果之间无显著相关性。此退变与患者年龄相关,而与骨密度和术前腰椎影像学测量指标无显著相关性。

Objective：To investigate the relationship between degeneration of cranial adjacent segment after single-segment instrumented fusion and its clinical results,and analyze the risk factors of degeneration of cranial adjacent segment.Method：A retrospective study of 49 patients who underwent pedicle screws fixation and posterior lumbar interbody fusion（PLIF） at the L4/5 segment for lumbar degenerative diseases between October 2004 and May 2009 was performed.There were 22 males and 27 females with the mean age of 53.4 years（range,28-72 years）.We measured BMD,and the vertebral height,dynamic intervertebral angle,displacement of slippage of both the fusion segment and cranial adjacent segment.We also measured the lumbar lordosis from L1 to S1,and at the fusion segment by Cobb′s method.Lumbosacral joint angle was also measured.The clinical results were assessed by using JOA score and Oswestry dysfunction index（ODI）.Patients were divided into two groups according to postoperative progression of L3/4 degeneration：group 1 with no progression of L3/4 degeneration and group 2 with progression of L3/4 degeneration.The clinical and radiologic results were compared.Result：The average follow-up period was 29.3 months（range,13-52 months）.All patients had no neurologic deterioration.There were 11 patients（22%） who showed radiologic progression of L3/4 degeneration.There was significant difference between the age of the two groups.But no significant difference between the two groups in BMD,lumbar lordosis,lumbosacral joint angle,lordosis and displacement of slippage of fusion segment preoperatively（P〉0.05）.Significant differences were observed in the changes of vertebral height,dynamic intervertebral angle and the progression of slippage at the cranial adjacent segment（L3/4） at final follow-up between the two groups.However,there was no significant difference between the two groups in the improvement of ODI and JOA at final follow-up（P〉0.05）.Age was found positively related to the change of vertebral height,dynamic intervertebral angle and the progression of slippage at the cranial adjacent segment at final follow-up.The relation coefficients were 0.353,0.521,0.472 respectively.Conclusion：After single-segment instrumented fusion,there is no significant correlation between the radiologic degeneration of cranial adjacent segment and its clinical results.Age would be related to this adjacent segment degeneration,while there might be no significant relationship between cranial adjacent segment degeneration and such risk factors as BMD,preoperative radiologic parameters.