Displaced femoral neck fracture: comparison of primary total hip replacement with secondary replacement after failed internal fixation: a 2-year follow-up of 84 patients.

INTRODUCTION: Recent randomized controlled trials have shown that for the active and lucid elderly patient with a displaced femoral neck fracture, a primary total hip replacement (THR) is superior to internal fixation (IF) regarding the need for secondary surgery, hip function and health-related quality of life (HRQoL). Despite the high failure rate for IF, the method is still recommended for this patient cohort by some authors. One argument is that if IF fails, there is always the possibility of performing a secondary salvage THR. The main aim of our study was to determine whether a primary THR, as compared to a secondary THR after failed IF, gives a better outcome after 2 years.

METHODS: We compared outcome for 43 patients with a primary THR to the outcome for 41 patients who were treated with a secondary THR after failed IF. All patients (mean age 80 years) were lucid and had a displaced femoral neck fracture. Hip function (Charnley score) and health-related quality of life (HRQoL, EQ5D) were assessed 2 years after the THR procedure.

RESULTS: Hip function was better in the primary THR group: the mean Charnley score was 15/18 as compared to 13/18 in the secondary THR group (p < 0.001). The patients with failed IF who later underwent a secondary THR experienced a more pronounced decrease in HRQoL (EQ-5D index score) during the first year of treatment compared to patients in the primary THR group, with a difference of 0.25 in the EQ-5D index score at the 4-month follow-up (p = 0.02).

INTERPRETATION: We found that a secondary THR after failed IF results in inferior hip function compared to a primary THR for a displaced femoral neck fracture in the active and lucid elderly patient. Moreover, the patients with failed IF had to undergo at least one re-operation and experienced a significant reduction in HRQoL before the salvage THR.