Metal-on-metal hip resurfacing is increasingly common. Patients suitable for hip resurfacing are often young, more active, may be in employment and may have bilateral disease. One-stage bilateral total hip replacement has been demonstrated to be as safe as a two-stage procedure and more cost effective. The aim of this study was to compare the in-patient events, outcome and survival in patients undergoing one-stage resurfacing with a two-stage procedure less than one-year apart.

Methods. Between July 1994 and August 2006 a consecutive series of 93 patients underwent bilateral hip resurfacing within a year. 34 patients in the one-stage group. 44 patients in the two-stage group. The age, gender, diagnosis, ASA grade, total operative time, blood transfusion requirements, medical complication, surgical complications, length of stay, duration of treatment, revision and Oxford hip scores were recorded.

Results. There were no significant differences in age, gender, ASA grade between the one-stage and the two-stage. There were 4 minor complications in the one stage group and 5 in the two-stage group. All patients that suffered a complication made a full recovery. There was no significant difference in the blood transfusion requirements. The mean anaesthetic time was 136 minutes in the one stage group and 92 minutes in the two-stage group with a significant mean difference of 44 minutes(95% c.i. 31–52). The mean total length of hospital stay was 11 days in the one-stage group and 16 days in the two-stage group with a significant mean difference of 5 days(95\% c.i. 4.0–6.9). The mean difference in length of treatment time of 6.5 months was significant(95\% c.i. 4.0–9.0).

No patients have undergone a revision procedure during the study period and no patient is awaiting revision surgery.

Conclusions. This study demonstrates no detrimental effects when performing a one-stage bilateral metal-on-metal hip resurfacing in comparison to a two-stage procedure. There are advantages of a one-stage procedure over a two-stage procedure for bilateral disease. Total hospital stay is reduced by 31.3% and the mean length of treatment is reduced by 50.0%. These benefits do not appear to come at the cost of increase complications. The complication rate in both groups was very low and all of the complications were short-term and are unlikely to have any bearing on the longevity of the prosthesis.