title: Risk factors for intraoperative calcar fracture in cementless total hip arthroplasty.
abstract: OBJECTIVE
  Intraoperative periprosthetic femoral fracture is a known complication of cementless total hip arthroplasty (THA). We determined the incidence of--and risk factors for--intraoperative calcar fracture, and assessed its influence on the risk of revision.
  
  
  METHODS
  This retrospective analysis included 3,207 cementless THAs (in 2,913 patients). 118 intraoperative calcar fractures were observed in these hips (3.7%). A control group of 118 patients/hips without calcar fractures was randomly selected. The mean follow-up was 4.2 (1.8-8.0) years. Demographic data, surgical data, type of implant, and proximal femur morphology were evaluated to determine risk factors for intraoperative calcar fracture.
  
  
  RESULTS
  The revision rates in the calcar fracture group and the control group were 10% (95% CI: 5.9-17) and 3.4% (CI: 1.3-8.4), respectively. The revision rate directly related to intraoperative calcar fracture was 7.6%. The Hardinge approach and lower age were risk factors for calcar fracture. In the fracture group, 55 of 118 patients (47%) had at least one risk factor, while only 23 of118 patients in the control group (20%) had a risk factor (p = 0.001). Radiological analysis showed that in the calcar fracture group, there were more deviated femoral anatomies and proximal femur bone cortices were thinner.
  
  
  CONCLUSIONS
  Intraoperative calcar fracture increased the risk of revision. The Hardinge approach and lower age were risk factors for intraoperative calcar fracture. To avoid intraoperative fractures, special attention should be paid when cementless stems are used with deviant-shaped proximal femurs and with thin cortices.
authors.affiliation: a Department of Orthopaedics, Traumatology and Hand Surgery , Kuopio University Hospital , Kuopio .
authors.forename: Simo S A
authors.initials: SS
authors.lastname: Miettinen
authors.affiliation: b Department of Orthopaedics and Traumatology , Helsinki University Hospital and University of Helsinki .
authors.forename: Tatu J
authors.initials: TJ
authors.lastname: Mäkinen
authors.affiliation: c Department of Orthopaedics and Traumatology , Turku University Central Hospital , Turku .
authors.forename: Inari
authors.initials: I
authors.lastname: Kostensalo
authors.affiliation: c Department of Orthopaedics and Traumatology , Turku University Central Hospital , Turku .
authors.forename: Keijo
authors.initials: K
authors.lastname: Mäkelä
authors.affiliation: d School of Health Sciences , University of Tampere , Tampere .
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: a Department of Orthopaedics, Traumatology and Hand Surgery , Kuopio University Hospital , Kuopio .
authors.forename: Jukka S
authors.initials: JS
authors.lastname: Kettunen
authors.affiliation: b Department of Orthopaedics and Traumatology , Helsinki University Hospital and University of Helsinki .|e Pihlajalinna Oy , Helsinki , Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Remes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D016022:Case-Control Studies; D005260:Female; D005264:Femoral Fractures / Q000453:epidemiology*; D006621:Hip Joint / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome