title: Peroneal Tendon Instability in Intra-Articular Calcaneus Fractures: A Retrospective Comparative Study and a New Surgical Technique.
abstract: OBJECTIVE
  To compare the prevalence of peroneal tendon instability as determined by intraoperative evaluation versus preoperative computed tomography (CT) scans, and to identify specific risk factors that correlate with tendon instability.
  
  
  METHODS
  Retrospective comparative study.
  
  
  METHODS
  Level 1 trauma hospital.
  
  
  METHODS
  Patients with operatively treated intra-articular calcaneus fractures managed between January 1, 2002 and December 31, 2012 were reviewed for evidence of peroneal tendon instability. Of 254 fractures, 155 intra-articular calcaneus fractures met inclusion criteria and were available for final analysis.
  
  
  METHODS
  Operative notes were reviewed to confirm intraoperative testing for superior peroneal retinaculum (SPR) integrity and peroneal tendon stability. Preoperative CT scan and plain radiographs were evaluated for presence of peroneal tendon dislocation, fibular fracture or "fleck" sign, excessive lateral wall displacement, and/or calcaneal fracture-dislocation.
  
  
  METHODS
  Peroneal tendon stability was determined with intraoperative assessment of the intact SPR and its confluence with the peroneal tendon sheath. The incidence of peroneal tendon instability on intraoperative assessment was compared with preoperatively identified tendon dislocation on CT scan. Prevalence of peroneal tendon dislocation was determined using each diagnostic method. Risk factors for tendon instability were identified using a multivariate regression model.
  
  
  RESULTS
  There was significantly higher prevalence of peroneal tendon instability as determined by preoperative imaging (30%; n = 47/155) compared with intraoperative retinaculum testing (11.6%; n = 18/155) (P < 0.001). Intraoperative tendon instability was significantly associated with increased fracture classification severity, fibular fracture/"fleck" sign, and fracture-dislocation.
  
  
  CONCLUSIONS
  Intraoperative evaluation of the SPR should be used in conjunction with preoperative imaging for diagnosis of peroneal instability in the setting of operatively treated, intra-articular calcaneus fractures.
  
  
  METHODS
  Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: *Department of Orthopaedics, University of Rochester, Rochester, NY; and †Orthopaedic Trauma Service, Florida Orthopaedic Institute, Tampa, FL.
authors.forename: John P
authors.initials: JP
authors.lastname: Ketz
authors.forename: Michael
authors.initials: M
authors.lastname: Maceroli
authors.forename: Edward
authors.initials: E
authors.lastname: Shields
authors.forename: Roy W
authors.initials: RW
authors.lastname: Sanders
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064386:Ankle Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D002111:Calcaneus / Q000000981:diagnostic imaging / Q000601:surgery*; D015897:Comorbidity; D005260:Female; D006801:Humans; D057072:Intra-Articular Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods / Q000706:statistics & numerical data; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013708:Tendon Injuries / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D055815:Young Adult