title: Posterior Facet Settling and Changes in Bohler's Angle in Operatively and Nonoperatively Treated Calcaneus Fractures.
abstract: BACKGROUND
  Patients with calcaneus fractures often exhibit settling of the posterior facet with a corresponding decrease in Bohler's angle (BA) following either operative or nonoperative treatment. Both injury BA and postoperative BA have been shown to be prognostic for outcomes; however, the demographic and surgeon-specific factors that may contribute to settling have not been critically examined in the literature. The purpose of this study was to identify these causative factors.
  
  
  METHODS
  234 patients with intra-articular calcaneus fractures were analyzed. All patients had preoperative plain radiographs, at least 5 months of orthopedic follow-up, and computed tomography scanning performed. BA was measured on the injury radiographs for all patients. For operatively treated patients, BA was measured on the immediate postoperative radiographs and compared with the last available radiograph. For nonoperatively treated patients, BA was measured on the last available radiograph. All patients were fully weightbearing at the time of final follow-up but not on initial radiographs due to their recent injury. Demographic data including age, gender, energy of injury mechanism, tobacco use, diabetes, osteoporosis, rheumatoid arthritis, and substance/alcohol abuse were retrospectively collected. Fractures were classified using the Essex-Lopresti and Sanders classifications. Time to full weightbearing was documented, as were any reports of noncompliance with weightbearing restrictions. For patients treated operatively, type of fixation (calcaneal-specific perimeter plate, nonperimeter plate, screw fixation), use of locking screws, use of bone graft or graft substitutes, and the number of screws supporting the posterior facet were documented.
  
  
  RESULTS
  There was a statistically significant amount of settling within the operative and nonoperative groups, but there was no statistically significant difference in settling of BA between the groups. The average settling of BA for the operative and nonoperative group was 8 degrees. Age greater than 50 years, diabetes, and alcohol abuse were all statistically significant and independent predictors of BA settling irrespective of treatment.
  
  
  CONCLUSIONS
  The amount of BA settling between the operative and nonoperative group was not significant and showed an average decrease of 8 degrees in each group. However, the amount of settling that we found, irrespective of treatment, increased with patient age, alcohol abuse, and diabetes.
  
  
  METHODS
  Level III, retrospective comparative study.
authors.affiliation: Harvard Combined Orthopaedic Residency Program, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA tagonzalez@partners.org.
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Gonzalez
authors.affiliation: Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Lucas
authors.affiliation: KSF Orthopaedic Center, P.A., Orthopaedic Surgery, Houston, TX, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Miller
authors.affiliation: Harvard Combined Orthopaedic Residency Program, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: I Leah
authors.initials: IL
authors.lastname: Gitajn
authors.affiliation: Orthopedic Center, Boston Children's Hospital, Boston, MA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.affiliation: Orthopaedic Surgery, Harvard Medical School; Division of Foot and Ankle Surgery, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: John Y
authors.initials: JY
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016512:Ankle Injuries / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D002111:Calcaneus / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D005260:Female; D005592:Fracture Fixation / Q000379:methods*; D006801:Humans; D057072:Intra-Articular Fractures / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016474:Weight-Bearing
keywords: Bohler’s angle; calcaneus fracture; foot and ankle; intra-articular; outcomes; posterior facet settling