Pedicle Subtraction Osteotomy with a Cage Prevents Sagittal Translation in the Correction of Kyphosis in Ankylosing Spondylitis

Abstract

Background:Sagittal translation (ST) is an accidental event that surgeons commonly encounter during a spinal osteotomy in the correction of kyphosis in ankylosing spondylitis (AS). However, there is a paucity of effective techniques to prevent ST. The purpose of this study was to propose a pedicle subtraction osteotomy (PSO) with a cage as a method to prevent ST and to explore the efficacy and feasibility of this method in the treatment of kyphosis in AS.Methods:We retrospectively reviewed 89 consecutive patients with AS kyphosis who underwent a PSO (Group B, 46 patients) or a PSO with a cage (Group A, 43 patients) from February 2009 to December 2013. Pre- and post-operative radiographic results were reviewed. ST and complications were analyzed in both groups. Clinical assessment was performed using the Scoliosis Research Society-22 (SRS-22) outcomes metric. The patients were followed up for at least 2 years.Results:Group A achieved the same re-alignment of the kyphotic spine as Group B. Two (4.7%) of the 43 patients in Group A and 14 (30.4%) of the 46 patients in Group B had intraoperative ST (χ2 = 10.020, P = 0.002). Significant differences were identified between the two groups in the height change of the osteotomized column. SRS-22 scores improved significantly in both groups. Seven patients experienced neurologic complications (1 in Group A and 6 in Group B). Eight patients had cerebrospinal fluid leakage (2 in Group A and 6 in Group B).Conclusion:PSO with a cage significantly avoided ST during the osteotomy procedure and might represent a new, safe, and feasible choice for treating patients with AS kyphosis.

Modified Closing-Opening Wedge Osteotomy to Correct Kyphosis in Ankylosing Spondylitis

“…Theoretically, the intact lower articular processes can enhance the stability of the posterior column, protect the lower nerve roots, and reduce the incidence of ST. In addition, some researchers have demonstrated [21] that PSO with a cage placed in the osteotomy gap can significantly reduce the incidence of ST because the cage would fall into the osteotomized vertebra and act as a stable link between the upper and the lower sides of the osteotomy site during the closure of the gap. In contrast, only the caudal part of the cage sinks into the osteotomized vertebra in mCOWO, while the cranial part does not.…”

Comparison of loss of correction between PSO and VCD technique in treating thoracolumbar kyphosis secondary to ankylosing spondylitis, a minimum 2 years follow-up

“…On these images, we measured spinal parameters including (1) sagittal vertical axis (SVA) [8], the distance measured between the C7 plumb line and the posterosuperior corner of S1 vertebra; (2) global kyphosis (GK) [9], the angle between the superior endplate of the maximally tiled upper end vertebra and the inferior endplate of the maximally tilted lower end vertebra (Fig. 2a); (3) lumbar lordosis (LL) [10], the angle between the superior endplate of L1 and S1, positive value indicates lumbar kyphosis and negative value indicates lumbar lordosis (Fig. 2a); (4) angle of instrumented levels (AIL), the Cobb angle between the upper end plate of the proximal fixed segment and the lower end plate of the distal-fixed segment.…”

Literature review of non-pharmacological treatment for patients with axial spondyloarthritis

“…Evidence regarding spinal surgery is limited to retrospective studies that have demonstrated the effectiveness of surgical treatment for spinal kyphosis in patients with advanced axSpA. Several case reviews have shown that spinal www.kjim.org https://doi.org/10.3904/kjim.2023.485 osteotomies using different surgical techniques have good outcomes [39][40][41]. However, other studies have reported perioperative complications with 2.4-4.0% mortality and 4.9% permanent neurological sequelae [42][43][44].…”