title: Direct stabilization of lumbar spondylolysis with a hook screw: mean 11-year follow-up period for 113 patients.
abstract: METHODS
  A retrospective study involving 113 patients with a spondylolysis who underwent direct repair with a hook screw was conducted.
  
  
  OBJECTIVE
  Spondylolysis with instability can produce low back pain. In adults, fusion of the affected level is the gold standard of treatment. In the adolescent, direct repair of the lysis can save a functional segment.
  
  
  BACKGROUND
  It has been proved that direct repair of spondylolysis can accomplish restitutio ad integrum for a functional segment. So far, only short-term results are available in the literature.
  
  
  METHODS
  This study involved 113 patients who underwent direct repair of spondylolysis with a hook screw according to Morscher. After an average follow-up period of 11 years, the patients were reviewed. The main issue was the question of fusion. For this purpose, plain radiographs were taken. For doubtful cases or for the patient experiencing pain, conventional tomography scans or computed tomography scans were taken.
  
  
  RESULTS
  The pseudarthrosis rate was 13.3%. The fusion rate for patients younger than 14 years was higher than that for older patients, especially those older than 20 years.
  
  
  CONCLUSIONS
  Direct repair of spondylolysis can be recommended for patients with a growing skeleton, a slight slip, an instability, or failure of conservative treatment. Thereby, a functional segment can be saved with a relatively small operation.
authors.affiliation: Department for Spine Surgery, Hospital for Orthopaedic Surgery Stolzalpe, Austria. gerd.ivanic@lkh-stolzalpe.at
authors.forename: Gerd M
authors.initials: GM
authors.lastname: Ivanic
authors.forename: T Peter
authors.initials: TP
authors.lastname: Pink
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Achatz
authors.forename: John-Christopher
authors.initials: JC
authors.lastname: Ward
authors.forename: Nicolaus C
authors.initials: NC
authors.lastname: Homann
authors.forename: Michael
authors.initials: M
authors.lastname: May
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001863:Bone Screws / Q000009:adverse effects; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000209:etiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D011542:Pseudarthrosis / Q000209:etiology; D012189:Retrospective Studies; D018570:Risk Assessment; D013123:Spinal Fusion / Q000009:adverse effects / Q000295:instrumentation*; D013169:Spondylolysis / Q000150:complications / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome