Recovery of Hip Muscle Strength after Rotational Acetabular Osteotomy Using the Combined Approach

Background: Either a combined approach or a transtrochanteric approach, performed with the patient in the lateral decubitus position, is used in Rotational Acetabular Osteotomy (RAO) to treat symptomatic hip dysplasia. Muscle strength after RAO using the transtrochanteric approach has been reported, but muscle strength after RAO using the combined approach has not been well studied. We aimed to investigate muscle strength and gait speed over a one-year follow-up period after RAO using the combined approach. Methods: Data from 124 patients who underwent RAO (129 hips) were analyzed retrospectively. Patients’ mean age was 44 years (14-64) and mean Body Mass Index (BMI) was 23 kg/m2 (16-36). Isometric hip flexion, abduction, and extension strengths and gait speed were measured before surgery and three months, six months, and one year after surgery. We assessed whether age and BMI were correlated with one-year postto pre-operative strength ratio. Results: Muscle strength had not changed significantly three months after surgery but had significantly improved at six months, exceeding pre-operative strength. One year after surgery, muscle strength of the treated hip exceeded that of the contralateral hip. Gait speed was significantly lower than pre-operative speed three months after surgery, recovered to pre-