Bilateral total hip arthroplasty (Bi THA) for disabling bilateral hip osteoarthritis can be performed in one or two operative sessions. The objective of this study was to compare the complication rates of a group of patients who had bilateral THA in one operating session (Bi-1S THA) to a matched group of patients who had bilateral THA in two separate operating sessions (Bi-2S THA).

This retrospective case-control study compared 84 Bi-1S THA matched to 84 Bi-2S THA by age, gender, diagnosis, ASA score (1–2) and surgical approach. The minimum follow-up was 12 months. Complication rates, total blood loss, number of blood transfusion units, and functional outcomes were assessed.

Twelve patients (14.3%) in the Bi-1S THA group had minor or major complications, compared to twenty-one (25%) in the Bi-2S THA group (p=0.08): there were fewer minor complications in the Bi-1S THA group and a similar rate of major complications amongst the two groups. Total blood loss estimated using the OSTHEO formula was significantly lower in patients operated on by Bi-1S THA (1853±753mL versus 2804±1012mL, p <0.0001). The number of blood transfusion units was similar between the groups (0.5±0.8 versus 0.3±1.4 respectively, p=0.55). No significant difference was found regarding the functional results.

Under the conditions of this study, bilateral total hip arthroplasty in one operative session leads to fewer minor complications, and a similar rate of major complications, when compared to bilateral total hip arthroplasty in two separate sessions. This strategy can therefore be recommended for ASA 1 and 2 patients, under the age of 80 with disabling bilateral osteoarthritis.

III, retrospective comparative study.