Therapeutic effects of intra-articular botulinum neurotoxin in advanced knee osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a major cause of musculoskeletal pain that causes morbidity, physical limitation, and poor quality of life. The purpose of this study was to evaluate the therapeutic effects of intra-articular (IA) injection of botulinum neurotoxin A (BoNT/A) for advanced knee OA. METHODS: Twenty-four patients (38 knees) were enrolled, and the subjects were radiographically verified as having stage III or IV OA according to the Kellgren-Lawrence classification. We used the Western Ontario and McMaster Universities Osteoarthritis Index to evaluate the therapeutic effects monthly for 6 months. BoNT/A (100 U) was reconstituted with 4.0 mL saline and was injected into the symptomatic knee joints after baseline evaluation and 3 months later. RESULTS: The therapeutic effects of BoNT/A were clinically significant at 1 month after the first injection, but statistical significance was not noted until 3 months after the first IA injection. Pain and stiffness improved clinically; however, the effect of BoNT/A achieved statistical significance only for the pain subscale in stage III OA. There was no significant difference between the stage III and IV groups. There was no significant muscle atrophy or serious adverse effect in any group after treatment. CONCLUSION: IA BoNT/A provides a new therapeutic option for refractory pain in patients with advanced knee OA. Although IA BoNT/A appears to be effective and safe for the management of advanced knee OA, these results cannot be generalized to patients with mild knee joint pain or nonspecific soft tissue pain in the knee joint region.

Effect of intra-articular injection of hyaluronic acid in rheumatoid arthritis patients with knee osteoarthritis.

BACKGROUND: Intra-articular injection of hyaluronic acid (HA) is a well-documented treatment for knee osteoarthritis (OA). One of the multifactorial mechanisms is that exogenous HA can stimulate endogenous HA production. HA can regulate the growth and function of chondrocytes by binding to CD44 receptors on the chondrocytes. Synovitis is often found in patients with rheumatoid arthritis (RA) and is supposed to result from CD44 activity. The aim of this study was to investigate the effect of intra-articular injection of HA in patients with RA combined with knee OA. METHODS: Twenty RA patients with OA knees were enrolled; 11 patients were placed into a stage II group and 9 into a stage III group, in accordance with the Kellgren-Lawrence classification of knee OA. All patients received intra-articular injection of HA (ARTZ) once a week for 5 weeks, and were evaluated with the WOMAC index (including the pain, stiffness and physical function subscales) at baseline, week 5 and week 9. The Friedman test and Wilcoxon signed rank test with Bonferroni correction method were used for statistical analysis. RESULTS: The effect of intra-articular injection of HA was significant at week 5 (p < 0.0167) and persisted to week 9 (p < 0.0167). This therapy was equally efficacious with stage II and stage III patients, with no difference between the 2 groups. CONCLUSION: Intra-articular injection of HA was beneficial in patients with RA combined with knee OA.