title: A comparative analysis of spondylolysis repair.
abstract: METHODS
  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.
  
  
  OBJECTIVE
  To determine whether one technique was associated with higher radiographic, clinical, or implant failure.
  
  
  BACKGROUND
  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 I 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.
authors.affiliation: University of Toronto, Ontario, Canada.
authors.forename: V
authors.initials: V
authors.lastname: Dreyzin
authors.forename: S I
authors.initials: SI
authors.lastname: Esses
mesh_terms: D000328:Adult; D001863:Bone Screws; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D012086:Reoperation; D012189:Retrospective Studies; D013169:Spondylolysis / Q000453:epidemiology / Q000601:surgery*; D013997:Time Factors; D017211:Treatment Failure