Biomechanical changes with intraarticular injections of the Hyapro synovial fluid prosthesis in patients with gonarthrosis

Introduction Deforming osteoarthritis is the most common articular disease, with gonarthrosis accounting for a quarter of the patients aged 50 years and over. The disease is associated with impaired function, pain, disability, reduced quality of life and requires total joint replacement in severe cases. There is no clear understanding of the causes of the disease, however, the pathogenesis is well studied. Intra-articular injection of synovial fluid prostheses including hyaluronic acid is one of the approaches to restore the properties of synovial fluid. Stabilometry that is a rare use in orthopaedics, and no use in this aspect was added to the traditional treatment effectiveness assessment. The objective was to explore biomechanical changes in patients with Kellgren-Lawrence grade II-III gonarthrosis who underwent a series of three knee injections of synovial fluid prosthesis over a period of 6 months. Material and methods An open prospective non-comparative study was performed for 30 patients with unilateral gonarthrosis at a mean age of 60 (56; 63) years. The effect of intra-articular injections of a sterile mannitol heat-stabilized biopolymer synovial fluid prosthesis on the biomechanics was evaluated in two samples using WOMAC score (overall and ≥ 30). Biomechanics was assessed in the form of stabilometry. Standardized stabilography and questionnaires were used at 3 follow-up visits: at 0 month (before administration), at 3 and 6 months. Results General sample showed no cases of true drift of the stabilogram parameters, decreased area of the statokinesiogram, and the WOMAC ≥ 30 sample demonstrated an additional improvement in the speed parameters of vertical oscillation at 6 months, a decreased area of the statokinesiogram at 3 months and at 6 months, decreased energy costs at 6 months (p < 0.05). Discussion Positive changes in stabilometry indicated a decreased pain and fatigue reactions in a vertical static position in gonarthrosis during the treatment. Most effects were statistically significant in moderate and severe dysfunction and pain. Intra-articular injection of synovial fluid prosthesis objectively improved the physiometric parameters of the support reaction. Conclusion Three intra-articular injections of a synovial fluid prosthesis based on mannitol-stabilized hyaluronic acid used in gonarthrosis Kellgren-Lawrence grade II-III showed improved body posture parameters of maintaining upright posture and reduced energy consumption in moderate and severe knee pain according to dynamic stabilometry for at least 6 months.