Intraarticular gold microparticles using hyaluronic acid as the carrier for hip osteoarthritis. A 2-year follow-up pilot study.

We recently conducted a pilot study in which we discovered that introducing metallic gold microparticles into the knee joint can help reduce pain caused by osteoarthritis for up to two years. Additionally, we identified significant proteomic changes in the synovial fluid and serum within eight weeks of the procedure. In this study, we aimed to evaluate whether there may be a clinical relevant effect of intra-articular injection of gold microparticles on hip osteoarthritis. A cohort of 22 patients, aged ≥ 18 years, with pain ≥ 3 months, and Kellgren-Lawrence OA grade 2-4, were included. Metallic gold 20 mg, 72.000 pieces, 20-40 µ-meter BerlockMicroImplants (BMI) were injected into the hip joint using hyaluronic acid as the carrier. In total, we treated 26 hip joints. The primary outcome was the Western Ontario and McMaster Universities Arthritis Index (WOMAC). WOMAC pain decreased from 11 (2-20 to 3 (0-8), stiffness from 6 (0-8) to 1 (0-4), and activity from 43 (18-68) to 11 (0-27), all P = 0.0001. When adjusting for the minimally relevant differences, the P-values were 0.0015 for WOMAC pain, 0.26 for stiffness, and 0.011 for activity. Combined intraarticular treatment with metallic gold microparticles and hyaluronic acid may improve hip joint pain and function. Joint stiffness did not improve when assessed against the minimal clinically relevant difference. This study suggests a basis for a future placebo-controlled randomized trial of gold microparticles and hyaluronic acid in hip osteoarthritic patients.