Early dislocation after bipolar hemiarthroplasty of the hip

Article type: Research Article

Authors: Levi, N. | Gebuhr, P.

Affiliations: Department of Orthopaedic Surgery, Amager Hospital, University Hospital of Copenhagen, Italiensvej 1, Copenhagen 2300 S, Denmark

Note: [] Correspondence to: Niels Levi MD, PhD, Vermlandsgade 77, Copenhagen 2300 S, Denmark.

Abstract: The reported incidence of dislocation of a hip hemiarthroplasty varies from less than 1 to 10%. A suggested advantage of the bipolar design is improved stability of the prosthesis and resistance to dislocation. However, this proposed decreased rate of dislocation has been challenged. The aim of this study was therefore to assess the dislocation rate after bipolar hemiarthroplasty of the hip. A posterolateral approach was used for 197 consecutive bipolar hemiarthroplasty operations for subcapital femoral neck fractures. There were 164 women and 33 men, the average age being more than 80. A total of 11 bipolar hemiarthroplaties (1 in men and 10 in women) dislocated. The 6‐months dislocation rate was 1/33=3% for men and 10/164=6.1% for women. The overall 6‐months dislocation rate was therefore 11/197=5.6%. The average delay between the operation and the dislocation was 5 weeks (range 2 days to 6 months). We are uncertain whether the high frequency of dislocation in our series is related to surgical technique, patient population or prosthesis type. However, a review of the literature seems to suggest a significant correlation between the age of the patients and the dislocation rate.

Keywords: Hemiarthroplasty, hip, dislocation, luxation, fracture

Journal: International Journal of Risk and Safety in Medicine, vol. 13, no. 4, pp. 233-236, 2000