Low conversion rates toward total hip arthroplasty after hemiarthroplasty in patients under 75 years of age.

INTRODUCTION: An intracapsular fracture of the femoral neck is frequent in the elderly. Patients can be treated with either total hip arthroplasty or hemiarthroplasty. There is a continuous discussion about the treatment in elderly patients who are still healthy, active and mentally untroubled. A potential consequence of hemiarthroplasty, especially in the relatively young elderly, could be conversion to total hip arthroplasty. The conversion rate must be acceptable, and clinical outcome must be sufficient to justify the treatment with hemiarthroplasty in this group of patients. This study evaluates the conversion rate of hemiarthroplasty to total hip arthroplasty and clinical outcome in patients under 75 years of age.

METHODS: This study identified 248 patients, younger than 75 years at time of operation, with a fracture of the femoral neck treated with hemiarthroplasty. Patient-reported outcome measurements (VAS pain during rest and activity and WOMAC) were assessed by telephone interviews. Furthermore, radiographic evaluation for the presence of acetabular wear was performed.

RESULTS: At a follow-up of 5.1 (0.9-9.6) years, the conversion rate was 7.3%. Mean VAS pain in rest was 0.89 (0-10), the mean VAS pain during activity was 2.2 (0-10), and the WOMAC showed a mean of 16.51 (0-64). At time of follow-up, 38.7% of patients had died. Radiographic evaluation of the unrevised group showed in one patient signs of acetabulum wear.

CONCLUSION: Hemiarthroplasty in the relatively young elderly after a fracture of the femoral neck demonstrates an acceptable conversion rate. Furthermore, unrevised patients show low complaints of pain. To prevent one conversion to total hip arthroplasty, 13.7 patients should be treated with total hip arthroplasty that will not undergo a conversion at a later stage. Therefore, hemiarthroplasty remains a viable treatment of femoral neck fractures in relatively young patients. There seems to be no space for standardized decision making concerning the choice of treatment. An individual approach is required.