Bao Hongda, He Shouyu, Liu Zhen, Zhu Zezhang, Qiu Yong, Zhu Feng
From the Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
Spine (Phila Pa 1976). 2015 Mar 1;40(5):E293-300. doi: 10.1097/BRS.0000000000000744.
A retrospective radiographical study.
To compare compensatory behavior of coronal and sagittal alignment after pedicle subtraction osteotomy (PSO) and Smith-Petersen osteotomy (SPO) for degenerative kyphoscoliosis.
There was a paucity of literature paying attention to the postoperative imbalance after PSO or SPO and natural evolution of the imbalance.
A retrospective study was performed on 68 consecutive patients with degenerative kyphoscoliosis treated by lumbar PSO (25 patients) or SPO (43 patients) procedures at a single institution. Long-cassette standing radiographs were taken preoperatively, postoperatively, and at the last follow-up and radiographical parameters were measured. The lower instrumented vertebral level and level of osteotomy were compared between the patients with and without improvement.
Negative sagittal vertical axis (SVA) was observed in the PSO group postoperatively, implying an overcorrection of SVA. This negative SVA improved spontaneously during follow-up (P < 0.05). Coronal balance was found to worsen immediately postoperatively in the SPO group (P < 0.05). At the last follow-up, spontaneous improvement was observed in 15 patients and the average coronal balance decreased to 16.35 mm. For the 15 patients with improved coronal balance, fusion at L5 or above was more common compared with the 11 patients with persisted postoperative imbalance (P = 0.027), whereas no difference in term of levels of osteotomy was found (P > 0.05).
The overcorrection of SVA is more often seen in the PSO group. The coronal imbalance is more likely to occur in the SPO group. The postoperative sagittal imbalance often spontaneously improves with time. Lower instrumented vertebra at S1 or with pelvic fixation should be regarded as potential risk factors for persistent coronal imbalance in patients with SPO.
一项回顾性影像学研究。
比较经椎弓根截骨术（PSO）和史密斯-彼得森截骨术（SPO）治疗退变性脊柱侧凸后冠状面和矢状面排列的代偿行为。
关注PSO或SPO术后失衡及失衡自然演变的文献较少。
对在单一机构接受腰椎PSO（25例患者）或SPO（43例患者）手术治疗的68例连续退变性脊柱侧凸患者进行回顾性研究。术前、术后及末次随访时拍摄长片站立位X线片并测量影像学参数。比较改善和未改善患者的下固定椎水平及截骨水平。
PSO组术后观察到矢状面垂直轴（SVA）为负值，提示SVA过度矫正。该负SVA在随访期间自发改善（P<0.05）。SPO组术后冠状面平衡立即恶化（P<0.05）。在末次随访时，15例患者出现自发改善，平均冠状面平衡降至16.35mm。对于冠状面平衡改善的15例患者，与11例术后失衡持续的患者相比，L5或更高节段融合更为常见（P = 0.027），而截骨水平方面未发现差异（P>0.05）。
PSO组更常出现SVA过度矫正。SPO组更易发生冠状面失衡。术后矢状面失衡常随时间自发改善。SPO患者中，S1节段的下固定椎或伴有骨盆固定应被视为冠状面失衡持续存在的潜在危险因素。
3级。
