The aims of this study were to assess and quantify hip abductor muscle strength deficits after total hip arthroplasty (THA) and to determine associations with external factors. Studies reporting on hip abductor muscle strength before and/or after THA performed for osteoarthritis or atraumatic osteonecrosis of the hip were considered for inclusion. Data sources were Embase, Medline, and the Cochrane Central Register of Controlled Trials. Muscle strength on the affected side was compared with the healthy contralateral side or with control subjects. Study quality was assessed using a modified Newcastle-Ottawa Scale. Nineteen studies reporting on 875 subjects met the inclusion criteria. Patients scheduled for THA had a mean strength deficit of 18.6% (95% confidence interval (CI) [-33.9, -3.2%]) compared with control subjects. Abductor muscle strength then increased by 20.2% (CI [5.6, 34.8%]) at 4-6 months, 29.6% (CI [4.7, 54.4%]) at 9-12 months, and 49.8% (CI [-31.0, 130.6%]) at 18-24 months postoperatively compared with preoperative values. For unilateral THA, the mean torque ratio was 86.3% (CI [75.4, 97.2%]) and 93.4% (CI [75.1, 111.6%]) before and >24 months after THA, respectively. Study quality was low to moderate. Hip abductor muscle strength deficits may gradually improve during 24 months after THA possibly without complete recovery. Cautious interpretation of these findings is warranted because high-quality evidence is largely missing.

Inertial measurement units (IMUs) are commonly used for gait assessment, yet their potential for quantifying improvements in gait function and patterns after total hip arthroplasty (THA) has not been fully explored. The primary aim of this study was to compare spatiotemporal parameters and sagittal plane kinematic patterns of patients with hip osteoarthritis (OA) before and after THA, and to asymptomatic controls. The secondary aim was to assess the association between dynamic hip range of motion (ROM) during walking and the Hip Osteoarthritis Outcome Scores (HOOS). Twenty‐four patients with hip OA and 24 matched asymptomatic controls completed gait analyses using the RehaGait® sensor system. Patients were evaluated pre‐ and 1 year postoperatively, controls in a single visit. Differences in kinematic data were analyzed using statistical parametric mapping, and correlations between dynamic hip ROM and HOOS were calculated. Walking speed and stride length significantly increased (+0.08 m/s, p = 0.019; +0.06 m, p = 0.048) after THA but did not reach the level of asymptomatic controls (−0.11 m/s, p = 0.028; −0.14 m, p = 0.001). Preoperative hip and knee kinematics differed significantly from controls. After THA, they improved significantly and did not differ from controls. Dynamic hip flexion‐extension ROM correlated positively with all HOOS subscores (r > 0.417; p ≤ 0.001). The change in HOOS symptoms in patients was explained by the combination of baseline HOOS symptoms and change in dynamic hip ROM (r² = 0.748) suggesting that the additional information gained with IMU gait analysis helps to complement and objectify patient‐reported outcome measures pre‐ and postoperatively and monitor treatment‐related improvements.

Introduction: The aim of this study was to describe the indications and technical aspects of medial closing and lateral opening distal femoral osteotomy (MCDFO and LODFO) for patients with a valgus knee and to report clinical and radiological outcomes and complications. Methods: Over 6 years, 28 DFOs (22 MCDFO, 6 LODFO) were performed in 22 Patients. In this cohort study, we retrospectively analyzed clinical and radiological outcome measures as well as complications. Results: The median (range) age was 47 (17–63) years, height 1.68 (1.56–1.98) m, body mass 80 (49–105) kg, and body mass index (BMI) 27.4 (18.6–37.0) kg/m². The clinical follow-up was 21 (7–81) months, the need for total or unicompartmental knee arthroplasty (TKA/UKA) and hardware removal was followed up for 59 (7–108) months postoperatively. Preoperatively, hip-knee-ankle angle (HKA, negative values denote varus) was 7.0 (2.0–13.0)°, mechanical lateral distal femoral angle (mLDFA) was 83.7 (79.9–88.2)°, and mechanical proximal tibial angle (MPTA) was 89.0 (86.6–94.5)°. Postoperatively, HKA was −1.3 (−9.0–1.2)° and mLDFA was 90.8 (87.3–97.3)°. The incidence of minor and major complications was 25% and 14%, the incidence of delayed and nonunion was 18% and 4%, respectively. At the last follow-up, 18% of the patients had pain at rest, 25% during activities of daily living, and 39% during physical activity, and 71% were satisfied with the outcome. 7% of the cases received a TKA/UKA, 71% received a hardware removal. Conclusion: DFO is a reasonable treatment for lateral osteoarthritis in younger patients to avoid disease progression and the need for an UKA/TKA. However, there is a long rehabilitation time, a considerable risk for complications, and a high need for hardware removal. While many patients experienced symptoms at the long-term follow-up, most were satisfied with the outcome. Appropriate patient information is essential. Level of evidence Level IV, Case Series. Trial registration number NCT04382118, clinicaltrials.gov, May 11, 2020.