Femoral head reduction osteotomy with simultaneous periacetabular osteotomy for severe femoral head deformities.

Aims: The aim of this study was to describe femoral head reduction osteotomy (FHRO) and review its safety, the radiological correction which may be obtained, and the clinical results at a minimum follow-up of two years.

Methods: A total of 12 patients (12 hips) with a severe deformity of the femoral head, mainly from Perthes' disease, underwent FHRO using the surgical hip dislocation technique with an extended retinacular flap. Their mean age was 17 years (12 to 25). Radiographs were obtained before and after surgery to evaluate morphological parameters, articular congruence, and cartilage damage. Preoperative arthro-MRI was used to evaluate the condition of the cartilage and the spatial distribution of the damage. The clinical outcome was assessed using the Non-Arthritic Hip Score (NAHS), the Hip Outcome Score (HOS), and the modified Harris Hip Score (mHHS).

Results: At a mean follow-up of 4.6 years (2 to 9), all osteotomies had healed unremarkably and no patient had symptomatic avascular necrosis. The mean femoral head size index changed significantly from 120% (SD 10) before surgery to 100% (SD 10) after surgery (p = 0.004). The mean femoral head sphericity index also changed significantly from 71% (SD 10) to 91% (SD 7) (p = 0.002). The mean femoral head extrusion index changed significantly from 37% (SD 17) to 9% (SD 6) (p = 0.002). The mean NAHS score improved significantly from 41 (SD 18) to 69 points (SD 9) (p = 0.002). The mean HOS score also improved significantly from 56 (SD 24) to 83 (SD 17) (p = 0.010) and the mean mHHS score improved significantly from 46 (SD 15) to 76 points (SD 13) (p = 0.004).

Conclusion: Thus far, in this series, FHRO could be considered to be a safe surgical procedure with considerable potential for correcting severe deformities of the hip and improving patient-reported outcome measures.