Cemented Thompson versus cemented bipolar prostheses for femoral neck fractures.

PURPOSE: To compare early functional outcomes, complications, and mortality in elderly patients treated with the less costly, cemented Thompson prosthesis or the cemented bipolar prosthesis in order to identify factors affecting outcomes.

METHODS: Records of 303 patients with femoral neck fractures treated with the cemented Thompson monoblock prosthesis (n=206) or the cemented bipolar prosthesis (n=97) were reviewed. The choice of prosthesis was solely determined by surgeon's preference. Data relating to patient demographics, clinical and residential status, mobility, mental function, mortality, and complications during hospitalisation and rehabilitation were collected.

RESULTS: After adjusting for confounding variables, independent postoperative indoor mobility was associated with preoperative indoor mobility (p=0.002) and mental function (p=0.001), whereas postoperative outdoor mobility was associated with preoperative outdoor mobility (p=0.003), daily living activity (p=0.02), and mental function (p=0.02). Mortality within 6 months was only associated with poor mental function (p=0.009). At 6-month follow-up, there was no significant difference between the 2 types of prosthesis in terms of functional outcomes, mortality and complication rates.

CONCLUSION: In elderly patients with limited mobility, treatment with the bipolar prosthesis was not associated with better short-term outcomes than those receiving the Thompson prosthesis.