The gluteus medius (GMED) affects hip function as an abductor. We evaluated muscle volume and degeneration of the GMED by using CT-based analysis and assessed factors that affect hip abductor strength in patients with unilateral hip osteoarthritis (OA). We examined clinical and imaging findings associated with hip abductor strength in consecutive 50 patients with unilateral hip OA. Hip abductor muscle strength and Harris hip score (HHS) were assessed. Leg length discrepancy (LLD) and femoral offset were assessed using X-ray; CT assessment was employed for volumetric and qualitative GMED analysis. Volumetric analysis involved measurement of cross sectional area (CSA) and three-dimensional (3D) muscle volume. CT density was measured for the qualitative assessment of GMED degeneration with or without adjustment using a bone mineral reference phantom. Hip abductor muscle strength on the affected side was significantly lower than that on the contralateral healthy side and positively correlated with overall score and score for limping of gait of HHS, demonstrating the importance of hip abductor strength for normal hip function. A significant correlation was found between CSA and 3D muscle volume, unadjusted CT density and adjusted CT density, and hip abductor strength and these CT measurements. Multiple linear regression analysis demonstrated that 3D muscle volume, adjusted CT density, and LLD are independent factors affecting hip abduction. 3D measurement of muscle volume and adjusted CT density more accurately reflect quantity and the GMED quality than do conventional assessments. Increase in muscle volume, recovery of muscle degeneration, and correction of LLD are important for improving limping in patients with hip OA.

Fungal periprosthetic joint infections are one of the most intractable orthopedic disorders. Continuous local antibiotic perfusion allows direct administration of the antifungal agent micafungin into the local infection area at biofilm-disruptive concentrations, while controlling the dead space in addition to conventional treatment. Although the appropriate use of continuous local antibiotic perfusion requires familiarity with the characteristics of local antibiotic perfusion, it is a versatile treatment modality that can improve the clinical outcomes of fungal periprosthetic joint infection in combination with conventional treatment methods.

Periprosthetic joint infection (PJI) is a complication of peri-implant biofilm-based treatments and confers resistance to antimicrobial therapy. Integrating continuous local antibiotic perfusion (CLAP) with conventional surgery for PJI facilitates the local delivery of low-flow, high-concentration antimicrobials. This study aimed to evaluate the efficacy and safety of CLAP for treating PJI. This study included patients diagnosed with hip PJI who underwent debridement, antibiotics, and implant retention (DAIR) augmented by CLAP. Gentamicin was administered at a high concentration (1.2 mg/mL) and low flow rate (2.0 mL/h for 24 h). We evaluated implant survival and complication rates associated with adding CLAP to conventional DAIR surgery. Of the 22 patients, including 11 with chronic infection, DAIR surgery supplemented with CLAP resulted in implant survival in 20 patients (90.9%). In contrast, among 10 patients treated with DAIR without CLAP (non-CLAP group), implant survival was 70%. The mean follow-up period was 42.6 ± 31.5 (range, 12–161) months in the CLAP group and 56.8 ± 28.8 (range, 28–114) months in the non-CLAP group. During CLAP treatment, renal function worsened in two patients; however, it improved rapidly after CLAP completion and device removal. No major complications were observed. CLAP demonstrated promising results in treating acute and chronic PJI. However, monitoring and regulating blood antimicrobial levels is crucial to avoiding renal dysfunction. CLAP is a treatment option for PJI that can destroy bacterial biofilms.