Therapeutic exercise after intra-articular injection of botulinum toxin type A or hyaluronate injection resulted in significant improvement in pain and knee functioning in patients with knee OA, according to the study published in 'Journal of Rehabilitation Medicine'.

Xiao BAO et al. and his colleagues conducted a randomized controlled trial to study the effect of therapeutic exercises performed after the injection of botulinum toxin type A, hyaluronate or saline in knee OA patients.

A total of 60 patients with knee OA were randomly enrolled to 3 groups: Group A (injected with saline), Group B (injected with botulinum toxin A) and Group C (injected with hyaluronate). All the participants were asked to perform therapeutic exercise after injection. Visual Analogue Scale (VAS) score, Western Ontario and McMaster Universities Osteoarthritis Index questionnaire (WOMAC) score and Medical Outcomes Study 36-item Health Survey (SF-36)score were calculated at baseline and the end of 4th and 8th weeks.

The scores on the WOMAC and VAS scale were higher in the control group at the end of 4th and 8th week. Significant differences were observed in Mental Component Summary-36 scores (MCS-36) and Physical Component Summary-36 (PCS-36) between the 3 groups at the end of the 4th and 8th weeks. No significant differences were observed in MCS-36 and PCS-36 between groups A and C at the end of the 4th week. There were no significant changes observed in MRI and X-ray images of affected knees after the intervention.

The study findings suggested that therapeutic toxin following a botulinum toxin A or hyaluronate injection is effective for knee OA management. However, the efficacy of botulinum toxin A plus therapeutic exercise was more than hyaluronate injection plus therapeutic exercise.