title: Cannulated screw fixation of Jones fractures: a clinical and biomechanical study.
abstract: BACKGROUND
  Traditional nonsurgical treatment of Jones fractures has high rates of delayed union, nonunion, and refracture. Internal fixation has become the treatment of choice in athletes and active patients.
  
  
  OBJECTIVE
  The purpose of this study was (1) to review the short- and long-term clinical results of cannulated screw fixation of Jones fractures and (2) to perform a biomechanical evaluation of fatigue failure characteristics of several types of screws used in the fixation of Jones fractures.
  
  
  METHODS
  Retrospective case series and in vitro biomechanical study.
  
  
  METHODS
  Ten male and 5 female patients with Jones fractures fixed with cannulated screws ranging from 4 mm to 6.5 mm in diameter were evaluated by chart review, review of radiographs, and telephone interview. Mean follow-up from surgery to phone survey was 34 months. Screws ranging in size from 2.7 mm to 7.3 mm, both cannulated and noncannulated, stainless steel and titanium, were tested in the laboratory by cyclic loading to 250 N up to a maximum of 200,000 cycles.
  
  
  RESULTS
  Mean time to healing as shown on radiographs and by full activity after surgery were 7.3 and 7.9 weeks, respectively. All patients were able to return to their previous levels of activity. Screw fatigue data showed that the number of cycles to failure increased with increasing screw diameter. For 4-mm screws, mean number of cycles to failure was 4308 for cannulated titanium screws, 22,012 for cannulated stainless steel screws, and 44,523 for noncannulated stainless steel screws.
  
  
  CONCLUSIONS
  In our patients, cannulated screw fixation of Jones fractures was a procedure that was reliable, had low morbidity, and afforded athletes a quick return to activity.
  
  
  CONCLUSIONS
  The laboratory study suggests that the largest screw possible should be used for surgical fixation of these fractures and that screws less than 4 mm in diameter should be used with caution.
authors.affiliation: Ohio State University College of Medicine, Columbus, USA. kresse@uci.edu
authors.forename: Keri
authors.initials: K
authors.lastname: Reese
authors.forename: Alan
authors.initials: A
authors.lastname: Litsky
authors.forename: Christopher
authors.initials: C
authors.lastname: Kaeding
authors.forename: Angela
authors.initials: A
authors.lastname: Pedroza
authors.forename: Nilesh
authors.initials: N
authors.lastname: Shah
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001863:Bone Screws; D005260:Female; D005592:Fracture Fixation / Q000295:instrumentation*; D005596:Fractures, Closed / Q000601:surgery*; D006801:Humans; D008297:Male; D008682:Metatarsal Bones / Q000293:injuries* / Q000601:surgery*; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome