腰椎后外侧融合术对已存在退变的相邻节段的中远期影响

目的评估腰椎后外侧融合对已经存在退变但未纳入融合范围的相邻节段的中远期影响。方法对本院2004年1月—2005年12月因腰椎退行性疾患接受后路椎板切除减压、经椎弓根内固定、后外侧植骨融合的158例患者进行随访,采用影像学方法对其相邻节段的转归进行分析,比较相邻节段术前无退变和已存在退变的椎间盘的远期进一步退变情况及相应的临床功能。结果 102例病例获得完整随访,平均随访65.2个月(54~71个月),其中26例(25.5%)出现了相邻节段的影像学退变。在相邻上位节段中,术前无退变和已存在退变的椎间盘随访时出现进一步退变的发生率分别为13.5%(10/74)和35.7%(10/28),差异有统计学意义(P0.05)。在相邻下位节段中,术前没有退变和已存在退变的椎间盘随访时出现进一步退变的发生率分别为12.5%(6/48)和22.2%(4/18),差异无统计学意义。临床评价显示无论术前相邻节段有无退变,Oswestry功能障碍指数(ODI)在术后6个月时均较术前明显改善(P0.05),并在最终随访时得到保持,但术前相邻节段存在退变组随访时ODI明显高于无退变组(P0.05)。结论与术前无退变的相邻节段椎间盘相比,术前已存在退变的相邻椎间盘融合术后更容易出现进一步退变,而且会影响其远期的临床疗效。

Mid-long-term influence of lumbar posterolateral fusion on pre-existing degeneration at adjacent segments

Objective To identify the mid-long-term outcome of unfused adjacent disc with pre-operative existing degeneration after lumbar posterior lateral fusion (PLF).Methods The retrospective study included 158 patients who underwent surgery of PLF from January 2004 to December 2005.Radiographic grading scale was used to evaluate the preoperative and follow-up adjacent disc degeneration grade.The patients were divided into without preoperative degenerative adjacent disc group and with preoperative degenerative adjacent disc group, and the degeneration grade and clinical outcome were compared between the 2 groups.Results Finally there were 102 patients with completely follow-up records enrolled into the retrospective study, with a mean follow-up of 65.2 months (range, 54-71 months).Twenty-six patients (25.5%) were identified with adjacent segment degeneration (ASD) on roentgenographs.For the cranial level, the ASD was found in 13.5%(10/74) patients without preoperative degenerative discs and 35.7%(10/28) patients with preoperative degenerative discs, and the difference was statistically significant (P<0.05).For the caudal level, the difference12.5%(6/48) vs.22.2%(4/18)]was not statistically significant.At 6 months after operation, both groups showed significant improvement in Oswestry disability index (ODI), and compared with the pre-operation, the difference was statistically significant (P<0.05).Continued to the final follow-up, while there was significant different between 2 groups in final ODI.Conclusion The adjacent segment discs with pre-existing degeneration could have greater risk of advancing to further ASD as compared with the normal discs.