Will Immediate Postoperative Imbalance Improve in Patients With Thoracolumbar/Lumbar Degenerative Kyphoscoliosis? A Comparison Between Smith-Petersen Osteotomy and Pedicle Subtraction Osteotomy With an Average 4 Years of Follow-up. Issue 5 (1st March 2015)

• Record Type: Journal Article
• Authors: Bao, Hongda; He, Shouyu; Liu, Zhen; Zhu, Zezhang; Qiu, Yong; Zhu, Feng
• Is Part Of: Spine. Volume 40:Issue 5(2015)
• Publication Date: 2015-03-01
• Subjects: Smith-Petersen osteotomy -- pedicle subtraction osteotomy -- adult kyphoscoliosis -- imbalance -- overcorrection; Spine -- Abnormalities -- Periodicals; Spine -- Diseases -- Periodicals; Spine -- Surgery -- Periodicals; 616.73005
• DOI: 10.1097/BRS.0000000000000744
• Languages: English
• ISSNs: 0362-2436

Abstract

Abstract : Study Design: A retrospective radiographical study. Objective: To compare compensatory behavior of coronal and sagittal alignment after pedicle subtraction osteotomy (PSO) and Smith-Petersen osteotomy (SPO) for degenerative kyphoscoliosis. Summary of Background Data: There was a paucity of literature paying attention to the postoperative imbalance after PSO or SPO and natural evolution of the imbalance. Methods: 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. Results: 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). Conclusion: 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. Level of Evidence: 3 Abstract : There was a paucity of literature paying attention to the postoperative imbalance after pedicle subtraction osteotomy or Smith-Petersen osteotomy in patients with degenerative kyphoscoliosis and natural evolution of the imbalance. The results of our study showed that the overcorrection of sagittal vertical axis was more often seen in the pedicle subtraction osteotomy group and that the coronal imbalance was more likely to occur in the Smith-Petersen osteotomy group. The postoperative sagittal imbalance often spontaneously improves with time.