Femoral head diameter affects the revision rate in total hip arthroplasty: An analysis of 1,720 hip replacements with 9–21 years of follow-up

Background In a previous study concerning 1,660 ScanHip THAs that were followed for up to 12 years, the cumulative revision rate was not found to be dependent on whether a 22-mm or a 32-mm head size had been used. We have re-examined these patients to see whether a longer follow-up time (9–21 years) would disclose an effect of head size on the revision rate.

Patients and methods We analyzed the cumulative revision rate for 1,720 Scan Hip arthroplasties with either 22-mm or 32-mm femoral heads. The patients were followed for 9–21 years.

Results Arthroplasties with 32-mm head had 2.8-times higher cumulative revision rate than those with a 22-mm head. Older age reduced the risk of revision while male sex increased the risk.

Interpretation We found that head size affects revision risk, but that even in a reasonably large material a long follow-up time is required to disclose the effects of head size—and thus wear—on survival.