Does it need to perform anterior column support after Smith-Petersen osteotomy for ankylosing spondylitis?

Abstract

PurposeThe aim of this study was to determine whether anterior column support is required in Smith-Petersen osteotomy procedure with correction angles of more than 10°, while examining the subsequent healing patterns in relation to the disrupted area.MethodsAn analysis was done on 26 segments of 19 patients who showed a correction angle of more than 10° in the anterior opening after SPO. There were 17 male and two female patients with a mean age of 40 years (24–56 years). The mean follow-up period was 6.5 years (2–9.1 years). The patients were classified according to the site of the anterior opening, as the disc level, the lower end-plate of the upper body (upper body), or the upper end-plate of the lower body (lower body). The healing patterns of anterior opening and the radiological correction angles were evaluated relative to the opening site.ResultsIn all cases, bony fusion was confirmed at a mean period of 5.6 months (3–6.7 months) after surgery and the anterior opening gap was healed in 18 segments (69.2%). For patients that developed an opening in the upper body, all of the gaps were healed. The gaps in the lower body opening group were healed in 85.7% of the cases, and for the opening at the disc level, the gaps were healed only in 12.5% of the cases. The least amount of correction was obtained when anterior opening occurred in disc level.ConclusionsIn our study of subjects presenting with anterior opening angles from 10° to 32°, we obtained successful fusion without the need for additional anterior interbody fusion. Improved gap healing and increased correction angles were obtained when the opening was present in the upper or lower body endplates compared to those at the disc space level.

The clinical relevance of the presence of bridging syndesmophytes on kyphosis correction and maintenance following pedicle subtraction osteotomy for thoracolumbar kyphotic deformity in ankylosing spondylitis: a comparative cohort study

“…A relatively smaller amount of bony wedging osteotomy could achieve sufficient and even larger kyphosis correction when the adjacent discs were mobile and rod bending was appropriate. Despite the averaged amount of lordosing effect being a little less than the that of a single segment SPO, which generally resulted in 10° of correction [ 12 ], this discogenic lordosing effect might be essentially helpful to decrease the need of performing additional osteotomy and improve the realignment of sagittal profile.…”

“…After ethics approval was obtained from the hospital review board, a comprehensive retrospective review of clinical records and radiographic data was performed on AS-related thoracolumbar kyphosis surgically treated in our hospital from September 2010 to August 2014. The indications for corrective osteotomy surgery were hindered forward gazing, poor cosmetic appearance, early fatigue and back pain, compression of the viscera and lastly restricted personal hygiene [ 10 – 12 ]. The necessary enrollment criteria were as follows: (1) thoracolumbar/lumbar kyphosis with apex locating at or below T11; (2) PSO performed at lumbar vertebrae; and (3) follow-up period exceeding 2 years.…”

Treatment of kyphosis in ankylosing spondylitis by osteotomy through the gap of a pathological fracture: a retrospective study

“…Moreover, whether an anterior bone graft is actually needed is still a controversial topic in the field of spinal surgery [10, 30]. Some surgeons deem that the necessity of supplemental anterior fusion for pseudoarthrosis following PSO depends on the extent of the osteotomy closure and the anterior column defect.…”

“…If the osteotomy site can be completely closed, there is no need to perform an anterior interbody fusion. On the other hand, if the postoperative radiograph demonstrates an anterior column defect with a wide opening at the level of the pseudoarthrosis following PSO, a supplemental anterior fusion must be considered [10, 29]. Qian et al [29] performed PSO with a supplemental anterior fusion through the pseudoarthrosis in seven AS patients with severe kyphotic deformities.…”

“…Surgical treatments, including Smith-Petersen osteotomy (SPO or SPOs), pedicle subtraction osteotomy (PSO), vertebral column resection (VCR), polysegmental osteotomy (PO), or any combination of these, are commonly advocated for correcting kyphotic deformities secondary to AS [10, 11]. Presently, three surgical strategies are available for kyphosis correction in AS patients with a pathological fracture or pseudoarthrosis: (1) anterior debridement only; (2) PSO, bone graft fusion, and internal fixation; and (3) a combination of the anterior and posterior approaches [12].…”