Femoral derotational osteotomies for version abnormalities: a mean ten-year follow-up

This study aimed to characterize long-term patient-reported outcomes and survivorship following femoral derotational osteotomy (FDO).

A total of 77 hips (60 patients) between March 1997 and February 2019 who underwent FDO using an antegrade intramedullary device for excessive femoral anteversion or retroversion by a single-surgeon were retrospectively reviewed. Those with minimum five-year follow-up, with a mean of ten years (5.2 to 26.8), were included. Pre/postoperative modified Harris Hip Score (mHHS), postoperative patient global impression of change (PGIC), and patient acceptable symptomatic state (PASS) responses were collected. Survivorship free of conversion to arthroplasty was determined.

Overall, 90.0% of patients were female with a mean age of 29.6 years (14.4 to 60.9). A total of 52 hips had excessive anteversion with mean deformity of 38.3° (22° to 58°) and mean correction of 22.4° (15° to 40°); 25 hips had excessive retroversion with mean deformity of -8.7° (-24° to 2°) and mean correction of 21.7° (15° to 35°). Concomitant procedures included hip arthroscopy (32.5% of cases), periacetabular osteotomy (9.0%), and tibial derotational osteotomy (7.8%). Regardless of deformity, mean mHHS significantly improved (61.6 to 89.7, p < 0.001). The proportion of minimal clinically important difference (MCID), substantial clinical benefit (SCB), and PASS achievement was 94% (72 of 77), 84% (65 of 77), and 87% (67 of 77), respectively. For PGIC, 95.2% reported improvement, including 88.7% who reported themselves 'very much improved' or 'much improved'. Overall, 92.7% of anteverted and 85.7% of retroverted patients found their current symptomatic state satisfactory (p = 0.398). Three hips (two patients) underwent arthroplasty at mean 4.3 years. Survivorship free from conversion to arthroplasty was 95% at ten, 15, and 20 years.

In appropriately selected patients, FDO for hip pain related to excessive femoral anteversion or retroversion provides significant improvements in pain and function at a mean ten-year follow-up. Most patients report postoperative improvement and find their current symptomatic state satisfactory. The procedure effectively preserves the native hip joint with 95% long-term survivorship free of conversion to arthroplasty.