Clinical results and functional outcomes of primary and revision spinal deformity surgery in adults.

BACKGROUND Few studies have examined the postsurgical functional outcomes of adults with spinal deformities, and even fewer have focused on the functional results and complications among older adults who have undergone primary or revision surgery for spinal deformity. Our goal was to compare patient characteristics, surgical characteristics, duration of hospitalization, radiographic results, complications, and functional outcomes between adults forty years of age or older who had undergone primary surgery for spinal deformity and those who had undergone revision surgery for spinal deformity. METHODS We retrospectively reviewed the cases of 167 consecutive patients forty years of age or older who had undergone surgery for spinal deformity performed by the senior author (K.M.K.) from January 2005 through June 2009 and who were followed for a minimum of two years. We divided the patients into two groups: primary surgery (fifty-nine patients) and revision surgery (108 patients). We compared the patient characteristics (number of levels arthrodesed, type of procedure, estimated blood loss, and total operative time), duration of hospitalization, radiographic results (preoperative, six-week postoperative, and most recent follow-up Cobb angle measurements for thoracic and lumbar curves, thoracic kyphosis, and lumbar lordosis), major and minor complications, and functional outcome scores (Scoliosis Research Society-22 Patient Questionnaire and Oswestry Disability Index). RESULTS The groups were comparable with regard to most parameters. However, the revision group had more patients with sagittal plane imbalance and more frequently required pedicle subtraction osteotomies (p < 0.01). Patients in the primary group required more correction in the coronal plane than did patients in the revision group, whereas patients in the revision group required more correction in the sagittal plane. We found no significant difference between the two groups in the rate of major complications or in the Scoliosis Research Society-22 Patient Questionnaire functional outcome scores. There were significant improvements in many functional outcome scores in both groups between the preoperative and early (six-week) postoperative periods and between the early postoperative period and the time of final follow-up. CONCLUSIONS Revision surgery for spinal deformity in adults, although technically challenging and considered to present a higher risk than primary surgery, was shown to have a complication rate and outcomes that were comparable with those of primary spinal deformity surgery in adults. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.