Clinical and Radiographic Outcomes of Repair of Spondylolitic Spondylolisthesis via Direct Pars Repair

Abstract

Study Design. A retrospective chart review. Objective. The objective of this study is to investigate whether direct pars repair achieves bone healing and symptom relief in patients with spondylolitic spondylolisthesis. Summary of Background Data. While most cases of spondylolysis can be managed non-operatively, a small percentage of patients require surgical intervention. The outcome of direct pars repair via a standard pedicle-screw with wiring technique is controversial in patients with lumbar spondylolitic spondylolisthesis. Methods. Medical records of patients who had undergone an open surgical pars repair were retrospectively reviewed. Standard demographic and surgical parameters were collected. All patients underwent a primary repair of the pars with autograft or bone morphogenetic protein and instrumentation using a pedicle-screw with spinous process wiring. At 6-12 months after surgery, patient’s pain symptoms and postoperative CT scans were independently reviewed to assess healing; graded as non-union, partial union, or solid union. Results. There were 68 patients identified (33 male and 35 female) with an average age of 18.6 years. Mean estimated blood loss was 139 ml, and mean length of hospital stay was 3.7 days. CT evaluation revealed 35 (52%) solid unions, 21 (31%) partial unions, and 12 (18%) non-unions requiring revisions. Thirty-four (50%) patients had no postop pain, 24 (35%) had mild pain, 10 (15%) had persistent pain. The majority of patients with non-unions on CT had mild or persistent pain. Patients with no or mild pain tended to be younger than those with persistent pain (17.5 years vs 24.6 years, P=0.163). Conclusion. This study demonstrated a partial or complete union rate of 82% and a postoperative persistent pain rate of 15%. These figures are comparable to the previous study and this pedicle-screw with wiring technique can be worth trying before interbody fusion for spondylolytic spondylolisthesis to preserve anatomical lumbar motion.