Comparison between intra-articular Botulinum toxin type A, corticosteroid, and saline in knee osteoarthritis: a randomized controlled trial

Abstract

Objective: To compare the effectiveness of intra-articular injection (IAI) with Botulinum toxin type A (BTA), triamcinolone hexacetonide (TH), and saline in primary knee osteoarthritis. Design: A randomized controlled trial, with blinded patients and assessor. Setting: Outpatient rheumatology service. Subjects: Patients with knee osteoarthritis grades II and III. Interventions: Patients received IAI with 100 IU BTA, 40 mg TH, or isotonic saline solution (SS) 0.9%. Main measures: Patients were assessed at baseline and at 4, 8, and 12 weeks with the following instruments: visual analog scale for pain during movement (VASm; primary outcome) and visual analog scale for pain at rest (VASr), Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, 6-minute walk test, Timed Up and Go test, Short Form (SF)-36 questionnaire, range of motion of knee, and ultrasound (US) measurement of synovial hypertrophy. Results: In total, 105 patients were randomized, with 35 in each group; 96 were female (91.4%) and 9 were male (8.6%), with a mean age of 64.2 years (±6.9). At 12 weeks, the TH group showed better results only for VASm. At four weeks, the TH group showed better results than the BTA and SS groups for VASm (–68.9% (37.8) vs. –35.3% (40.3) vs. –35.9% (51.4)), WOMAC pain (–56.0% (30.7) vs. –30.8% (34.3) vs. –30.0% (39.9)), WOMAC stiffness (–53.4% (38.4) vs. –17.2% (59.3) vs. –17.3% (78.1)), WOMAC function (–48.2% (34.6) vs. 30.8% (33.6) vs. –13.6% (64.9)), WOMAC total score (–51.2% (31.0) vs. –30.9% (30.0) vs. –18.8% (54.8)), and US measurement of synovial hypertrophy (–11.6% (44.9) vs. –1.5% (47.9) vs. +28.6% (81.3)). Conclusion: IAI with TH had a higher effectiveness than that with TBA or SS in the short-term assessment (four weeks) for pain in movement, WOMAC, and US measurement of synovial hypertrophy.