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

To compare the effectiveness of intra-articular injection (IAI) with Botulinum toxin type A (BTA), triamcinolone hexacetonide (TH), and saline in primary knee osteoarthritis.

A randomized controlled trial, with blinded patients and assessor.

Outpatient rheumatology service.

Patients with knee osteoarthritis grades II and III.

Patients received IAI with 100 IU BTA, 40 mg TH, or isotonic saline solution (SS) 0.9%.

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.

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)).

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.