A comparative study of combining intra-articular injection of platelet-rich plasma or sodium hyaluronate with isotonic muscle strength training in treating knee osteoarthritis

Abstract

Objective To compare the efficacy of intra-articular injection of autologous platelet-rich plasma (PRP) with that of sodium hyaluronate for patients with knee osteoarthritis (KOA). Methods Fifty KOA patients were randomly divided into a PRP group (n=25) and a sodium hyaluronate group (n=25). Those in the PRP group were injected intra-articularly with 5 ml of autologous PRP every 2 weeks for 6 consecutive weeks, while the sodium hyaluronate group was given intra-articular injections of 2 ml of sodium hyaluronate once a week for 6 weeks. Both groups performed isokinetic strength training three times a week for 6 weeks. Before as well as 6 weeks, 3 months, 6 months and 12 months after the treatment, both groups were followed and evaluated using the Western Ontario and McMaster University osteoarthritis index (WOMAC). A Biodex System 4 isometric muscle strength testing system was used to evaluate the knees′ peak torque (PT) in flexion and extension, total power (TW), and average power (AP). Results Before the treatment there were no significant differences in pain, stiffness or average WOMAC score between the two groups. Afterward significant improvement was observed in the pain, stiffness and WOMAC scores of both groups. Compared with the sodium hyaluronate group, significantly greater decreases in the average WOMAC pain score were observed in the PRP group after the different intervals. That was also true of the average stiffness scores and the overall average WOMAC scores after 6 and 12 months. The flexor and extensor PT, TW and AP at the angular velocities of 60°/s and 90°/s also improved significantly in both groups after 6 weeks and 12 months, with the improvement of the PRP group significantly greater than that in the control group at the same time points. Conclusion Intra-articular injection of either autologous PRP or sodium hyaluronate can effectively alleviate the clinical symptoms of KOA when combined with isokinetic strength training. However, PRP is the more effective. Its use is worthy of clinical application and promotion. Key words: Knees; Osteoarthritis; Plasma; sodium hyaluronate; Isokinetic strength