A COMPARATIVE-ANALYSIS OF SPONDYLOLYSIS REPAIR

Study Design. This retrospective study compared patient outcome after two surgical techniques for pars interarticularis repair: 1) buck scre w fixation and 2) the modified Morscher-designed spondylolysis distrac tion hook. Objectives. To determine whether one technique was associat ed with higher radiographic, clinical, or implant failure. Summary of Background Data. Both techniques have been reported as giving good cli nical results. Methods. Twenty patients were included in this study. A ll patients had Type IIA spondylolytic defects with either a Grade 0 o r Grade 1 spondylolisthesis. Nine patients were treated with the Morsc her hook implant, and 11 patients were treated with the Buck technique . Results. Radiographic follow-up of the Morscher implants demonstrate d loosening in three and breakage in one. Radiographic analysis of the Buck technique demonstrated implant failure in one. Failure of healin g occurred in four instances with the Morscher implant compared with t wo instances with the Buck technique. Clinical outcome was assessed us ing the modified Prolo score. The mean outcomes were 6.33 in the Morsc her group and 6.09 in the Buck group. Conclusions. In these patients, the Morscher implant had a high failure rate. Furthermore, the clinica l outcome in this group of patients was poor using either technique.