title: Hemiarthroplasty for Displaced Femoral Neck Fractures in the Elderly Has a Low Conversion Rate.
abstract: Hemiarthroplasty (HA) has been a mainstay treatment for displaced femoral neck fractures for many years. The purpose of this study was to report the conversion rate of HA to total hip arthroplasty (THA) for displaced femoral neck fractures and compare outcomes between implant constructs (bipolar vs unipolar), fixation options (cemented vs cementless stems), and age groups (<75 years vs ≥75 years).
  
  
  
  We retrospectively reviewed the results of a consecutive cohort of 686 patients who underwent HA for the treatment of femoral neck fractures at our institution between 1999 and 2013 with a minimum of 2-year follow-up.
  
  
  
  The overall component revision rate, including conversion to THA, revision HA, revision with open reduction internal fixation, and Girdlestone procedure, was 5.6% (39/686). Seventeen patients (2.5%) were converted from HA to THA at an average of 1.9 years after index procedure. A significantly lower conversion rate of 1.4% (7/499 patients) was found in the older patient cohort (≥75 years old) compared to 5.3% (11/187) in the younger cohort. The most common causes for conversion surgery to THA were acetabular wear (5 patients), aseptic loosening (4 patients), and periprosthetic fracture (3 patients). There was a significantly lower rate of periprosthetic fracture (0.4% vs 2.5%, P value .025) in the cemented implant group compared to the cementless group. We observed a higher rate of dislocations in the bipolar vs unipolar group (3.8% vs 1%, P value .02) and no other significant differences between these groups.
  
  
  
  We observed a low reoperation rate for this cohort of patients, relatively higher conversion rates for the younger population, fewer periprosthetic fractures with the use of cemented stems, and no advantage of bipolar over unipolar prostheses.
authors.affiliation: Center for Hip & Knee Replacement, Department of Orthopaedic Surgery, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Grosso
authors.affiliation: Center for Hip & Knee Replacement, Department of Orthopaedic Surgery, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Danoff
authors.affiliation: Center for Hip & Knee Replacement, Department of Orthopaedic Surgery, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York.
authors.forename: Taylor S
authors.initials: TS
authors.lastname: Murtaugh
authors.affiliation: Center for Hip & Knee Replacement, Department of Orthopaedic Surgery, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York.
authors.forename: David P
authors.initials: DP
authors.lastname: Trofa
authors.affiliation: Center for Hip & Knee Replacement, Department of Orthopaedic Surgery, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Sawires
authors.affiliation: Center for Hip & Knee Replacement, Department of Orthopaedic Surgery, New York Presbyterian Hospital/Columbia University Medical Center, New York, New York.
authors.forename: William B
authors.initials: WB
authors.lastname: Macaulay
mesh_terms: D000077:Acetabulum / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D001843:Bone Cements; D005260:Female; D005265:Femoral Neck Fractures / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods; D062785:Hemiarthroplasty / Q000706:statistics & numerical data*; D006622:Hip Prosthesis / Q000009:adverse effects / Q000706:statistics & numerical data*; D006801:Humans; D004204:Joint Dislocations / Q000209:etiology; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000601:surgery; D011474:Prosthesis Design; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D001843:Bone Cements
keywords: bipolar; cemented femoral stem; cementless femoral stem; femoral neck fracture; hemiarthroplasty; unipolar