Kuhns Craig A, Bridwell Keith H, Lenke Lawrence G, Amor Courtney, Lehman Ronald A, Buchowski Jacob M, Edwards Charles, Christine Baldus
Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri, USA.
Spine (Phila Pa 1976). 2007 Nov 15;32(24):2771-6. doi: 10.1097/BRS.0b013e31815a7ece.
A retrospective long-term follow-up study.
Evaluate the fate of L5-S1 disc analyzing subsequent disc degeneration and associated risk factors for degeneration at minimum 5-year follow-up (average 9-year follow-up).
Two previous studies reported the results of long deformity fusions terminating at L5 with minimum 2-year follow-up only.
Thirty-one consecutive patients with an average age of 45 years (range, 20-62 years) were fused from the thoracic spine to L5 and were evaluated at a mean follow-up of 9.4 years (range, 5-20.1 year). Patients were evaluated before surgery, after surgery, and latest follow-up with radiographs and Scoliosis Research Society Patient Questionnaire-24 scores. Disc degeneration using validated radiographic Weiner grades. Grade 0 to 1 discs were "healthy" and Grade 2 to 3 were degenerated. Patients with "healthy" discs preoperative that subsequently degenerated were designated subsequent advanced degeneration (SAD).
Two out of 31 patients had preoperative advanced degeneration of the L5-S1 disc (Weiner grade 2-3). Three additional patients had an early revision to the sacrum secondary to sagittal imbalance not thought to be related to SAD. Twenty-six out of 31 patients were assessed as "healthy discs" preoperative (Weiner grade 0-1) and were evaluated for SAD. By latest follow-up, L5-S1 SAD developed in 18 of these 26 patients (69%). Risk factors for the development of SAD included long fusions extending into the upper thoracic spine down to L5 (P = 0.02) and having a circumferential lumbar fusion (P = 0.02). Although preoperative sagittal balance was not significantly different between the "healthy" and SAD group, sagittal balance at follow-up was: C7 plumb >5 cm in 67% of SAD patients and only 13% of "healthy" disc patients (P = 0.009). There was a trend toward inferior Scoliosis Research Society Patient Questionnaire-24 pain scores at follow-up in SAD patients (average score 4.1 vs. 3.4, P = 0.13). Eleven out of 30 patients (35%) had subsequent spinal surgery with 7 of 31 (23%) having extension of their fusion to the sacrum. An additional 6 of 31 (19%) were considered for extension to the sacrum but comorbidities precluded surgery (3 patients) or the patients declined further surgery (3 patients).
Advanced L5-S1 DDD developed in 69% of deformity patients after long fusions to L5 with 5 to 15 year follow-up. SAD frequently results in significant positive sagittal balance at a minimum 5-year follow-up. Long fusions to the upper thoracic spine down to L5 and circumferential fusion may further promote subsequent L5-S1 disc degeneration.
一项回顾性长期随访研究。
通过分析至少5年随访期（平均9年随访期）内L5 - S1椎间盘的退变情况及相关退变危险因素，评估L5 - S1椎间盘的转归。
此前两项研究仅报告了以L5为终点的长节段畸形融合术后至少2年的随访结果。
连续纳入31例平均年龄45岁（范围20 - 62岁）的患者，行从胸椎至L5的融合手术，并在平均9.4年（范围5 - 20.1年）的随访期进行评估。在手术前、手术后以及末次随访时，采用X线片和脊柱侧弯研究学会患者问卷24项评分对患者进行评估。采用经过验证的X线片Weiner分级评估椎间盘退变情况。0至1级椎间盘为“健康”，2至3级为退变。术前“健康”椎间盘随后发生退变的患者被定义为继发晚期退变（SAD）。
31例患者中有2例术前L5 - S1椎间盘存在晚期退变（Weiner分级2 - 3级）。另外3例患者因矢状面失衡早期翻修至骶骨，认为与SAD无关。31例患者中有26例术前被评估为“健康椎间盘”（Weiner分级0 - 1级）并对其进行SAD评估。至末次随访时，这26例患者中有18例（69%）发生了L5 - S1的SAD。SAD发生的危险因素包括从上胸椎至L5的长节段融合（P = 0.02）以及进行环形腰椎融合（P = 0.02）。虽然术前“健康”组和SAD组的矢状面平衡无显著差异，但随访时的矢状面平衡情况为：67%的SAD患者C7垂线距>5 cm，而“健康”椎间盘患者仅为13%（P = 0.009）。SAD患者随访时脊柱侧弯研究学会患者问卷24项疼痛评分有降低趋势（平均分4.1对3.4，P = 0.13）。30例患者中有11例（35%）随后接受了脊柱手术，31例中有7例（23%）将融合范围扩展至骶骨。另外31例中有6例（19%）考虑将融合范围扩展至骶骨，但合并症使手术无法进行（3例）或患者拒绝进一步手术（3例）。
在对L5进行长节段融合并随访5至15年的畸形患者中，69%发生了L5 - S1的晚期椎间盘退变。SAD在至少5年随访时常常导致显著的正矢状面平衡。从上胸椎至L5的长节段融合以及环形融合可能会进一步促进随后的L5 - S1椎间盘退变。
