Presciutti Steven M, Louie Philip K, Khan Jannat M, Basques Bryce A, Saifi Comron, Dewald Christopher J, Samartzis Dino, An Howard S
1Department of Orthopaedics, Emory University, Atlanta, GA USA.
2Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W. Harrison St., Suite 300, Chicago, IL 60612 USA.
Scoliosis Spinal Disord. 2018 Dec 27;13:28. doi: 10.1186/s13013-018-0174-y. eCollection 2018.
This study aims to determine if (1) loss of lumbar lordosis (LL), often associated with degenerative scoliosis (DS), is structural or rather largely due to positional factors secondary to spinal stenosis; (2) only addressing the symptomatic levels with a decompression and posterolateral fusion in carefully selected patients will result in improvement of sagittal malalignment; and (3) degree of sagittal plane correction achieved with such a local fusion could be predicted by routine pre-operative imaging.
A retrospective study design with prospectively collected imaging data of a consecutive series of surgically treated DS patients who underwent decompression and instrumented fusion at only symptomatic levels was performed. Pre- and post-operative plain radiographs and pre-operative magnetic resonance imaging (MRIs) of the spinopelvic region were analyzed. LL, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were assessed in all patients. As a requirement for the surgical strategy, all patients presented with a pre-operative PI-LL mismatch greater than 10. Post-operative complications were assessed.
Pre-operative MRIs and lumbar extension radiographs revealed a mean LL of 42 (range 10-66) and 48 (range 20-74), respectively, in 68 patients (mean follow-up 29 months). LL post-operatively was corrected to a mean PI-LL of 10. Of patients who achieved PI-LL mismatch within 10 on their pre-operative extension lateral lumbar radiographs, 62.5% were able to maintain a PI-LL mismatch within 10 on their initial post-operative films. Only 37.5% were not able to achieve that mismatch on extension radiographs ( = 0.001, OR = 9.58). Similarly, 54.2% were able to achieve a PI-LL < 10 on initial post-operative radiographs, when pre-operative MRI revealed a PI-LL mismatch within 10. In contrast, only 20.5% achieved that goal post-operatively if their mismatch was greater than 10 on their MRI ( = 0.003, OR = 4.25).
With a decompression and instrumented fusion of only the symptomatic levels in symptomatic DS patients, we were able to achieve a PI-LL mismatch to within 10. The loss of LL observed pre-operatively may be largely positional rather than structural. The amount of LL correction observed immediately after surgery can be predicted from pre-operative lumbar extension radiographs and supine sagittal MRI.
本研究旨在确定：（1）常与退变性脊柱侧凸（DS）相关的腰椎前凸（LL）丢失是结构性的，还是在很大程度上归因于继发于椎管狭窄的位置因素；（2）在精心挑选的患者中仅对有症状的节段进行减压和后外侧融合是否会改善矢状面排列不齐；（3）通过这种局部融合实现的矢状面矫正程度是否可通过常规术前影像学检查预测。
采用回顾性研究设计，对一系列连续接受手术治疗的DS患者的影像学数据进行前瞻性收集，这些患者仅在有症状的节段接受了减压和器械融合。分析了脊柱骨盆区域的术前和术后X线平片以及术前磁共振成像（MRI）。评估了所有患者的LL、骨盆入射角（PI）、骨盆倾斜度（PT）和骶骨坡度（SS）。作为手术策略的要求，所有患者术前PI-LL失配均大于10。评估了术后并发症。
68例患者（平均随访29个月）的术前MRI和腰椎后伸位X线平片显示，平均LL分别为42（范围10-66）和48（范围20-74）。术后LL矫正至平均PI-LL为10。在术前腰椎后伸侧位X线平片上PI-LL失配在10以内的患者中，62.5%在术后初始X线片上能够保持PI-LL失配在10以内。只有37.5%的患者在术后后伸位X线片上未能达到该失配（P = 0.001，OR = 9.58）。同样，当术前MRI显示PI-LL失配在10以内时，54.2%的患者在术后初始X线片上能够达到PI-LL < 10。相比之下，如果他们的MRI失配大于10，术后只有20.5%的患者达到该目标（P = 0.003，OR = 4.25）。
对有症状的DS患者仅对有症状的节段进行减压和器械融合，我们能够将PI-LL失配控制在10以内。术前观察到的LL丢失在很大程度上可能是位置性的而非结构性的。术后立即观察到的LL矫正量可根据术前腰椎后伸位X线平片和仰卧位矢状面MRI预测。
