A COMPARATIVE-ANALYSIS OF SPONDYLOLYSIS REPAIR

Study Design. This retrospective study compared patient outcome after two surgical techniques for pars interarticularis repair: 1) buck screw fixation and 2) the modified Morscher-designed spondylolysis distraction hook. Objectives. To determine whether one technique was associated with higher radiographic, clinical, or implant failure. Summary of Background Data. Both techniques have been reported as giving good clinical results. Methods. Twenty patients were included in this study. All patients had Type IIA spondylolytic defects with either a Grade 0 or Grade 1 spondylolisthesis. Nine patients were treated with the Morscher hook implant, and 11 patients were treated with the Buck technique. Results. Radiographic follow-up of the Morscher implants demonstrated loosening in three and breakage in one. Radiographic analysis of the Buck technique demonstrated implant failure in one. Failure of healing occurred in four instances with the Morscher implant compared with two instances with the Buck technique. Clinical outcome was assessed using the modified Prolo score. The mean outcomes were 6.33 in the Morscher group and 6.09 in the Buck group. Conclusions. In these patients, the Morscher implant had a high failure rate. Furthermore, the clinical outcome in this group of patients was poor using either technique.