Inferior outcome after intraoperative femoral fracture in total hip arthroplasty: outcome in 519 patients from the Danish Hip Arthroplasty Registry.

BACKGROUND: Intraoperative femoral fracture is a well known complication of primary total hip arthroplasty (THA). Experimental studies have indicated that intraoperative fractures may affect implant survival. Very few clinical data are available, however.

METHODS: We used data from the Danish Hip Arthroplasty Registry to identify patients in Denmark who underwent a primary THA due to primary osteoarthritis between 1995 and 2005 (n = 39,478). Data were linked to two national Danish databases in order to conduct time-dependent implant survival analyses. Implant survival and relative risk estimates were calculated for patients treated nonoperatively and for patients treated with osteosynthesis after sustaining intraoperative femoral fractures during THA surgery. THAs performed without sustaining intraoperative femoral fracture served as the reference group.

RESULTS: 282 patients (0.7%) were treated non operatively due to intraoperative femoral fracture and 237 patients (0.6%) were treated with osteosynthesis. In the 0-6 month postoperative period, the adjusted relative risk (RR) of revision was 1.5 (95% CI: 1.1-1.7) for patients treated nonoperatively and 5.7 (3.3-10) for patients treated with osteosynthesis. In the period from 6 months to 11 years postoperatively, we did not find any statistically significant differences in the RR of revision between the groups.

INTERPRETATION: Intraoperative fractures increase the relative risk of revision during the first 6 postoperative months. Thus, patients should be informed about the risk of revision after sustaining an intraoperative femoral fracture. Furthermore, initiatives aimed at reducing the risk of revision in the first 6 months following THA should be considered in patients with intraoperative fractures, including immediate change to a larger stem with distal fixation and restricted weight bearing.