P87. Strategies for prevention of pseudarthrosis in adult spinal deformity: cobalt chrome rod, 4-rod fixation, and oblique lumbar interbody fusion with sacropelvic fixation

BACKGROUND CONTEXT Restoration of the sagittal alignment in adult spinal deformity (ASD) can produce excellent radiological and clinical outcomes, but pseudarthrosis is one of the most common complications with an incidence of 0% to 29%. Various surgical options are reported for reducing the incidence of pseudarthrosis, but these methods are controversial and have limitations. PURPOSE The purpose of this study was to identify the methods for reducing the incidence of pseudarthrosis in the surgical treatment of ASD. STUDY DESIGN/SETTING Retrospective, consecutive case review. PATIENT SAMPLE A total of 186 consecutive patients with degenerative lumbar kyphosis (average age 70.8 years) who underwent a long-segment fixation with a minimum 2-year follow-up. OUTCOME MEASURES Description and analysis of X-ray changes. METHODS Subjects were classified into the pseudarthrosis group (n=39) and the non-pseudarthrosis group (n=147). For predicting the factors of pseudarthrosis, patient factors, radiologic parameters, and surgical factors which include rod materials (Titanium vs Cobalt Chrome), the use of 4-rod fixation and sacropelvic fixation, correction methods (pedicle subtraction osteotomy vs oblique lumbar interbody fusion), and the history of the previous spine surgery were analyzed. RESULTS The overall pseudarthrosis rate was 21% (39/186). No significant differences in the incidence of pseudarthrosis regarding patient factors and preoperative radiological parameters were found between the two groups (p >0.05). Significant differences were observed in the postoperative sagittal vertical axis and thoracic kyphosis angle (p CONCLUSIONS Applications of cobalt chrome rod, 4-rod fixation, or oblique lumbar interbody fusion procedure with sacropelvic fixation will be promising methods for reducing pseudarthrosis in surgically treated ASD. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.