Objective: To compare botulinum toxin type A injection with corticosteroid injection in the treatment of tennis elbow.
Design: In this prospective, randomized, double-blind, drug-controlled trial,19 affected elbows of 16 patients were randomly assigned to receive injection with botulinum toxin type A (Botox group) or triamcinolone acetonide (steroid group). We used the Visual Analog Scale, pain-free grip strength, and World Health Organization Quality of Life Brief Questionnaire to assess the perception of pain, grip strength, and quality of life, respectively. Measures were performed before and at 4, 8, and 12 wks after the treatment.
Results: Four weeks after the treatment, the Botox group had smaller decrease in pain (P = 0.02) but greater decrease in grip strength (P = 0.01). The difference in grip strength remained significant at 8 wks (P = 0.03). No significant differences in quality of life were observed throughout the study period.
Conclusions: Corticosteroid is superior to botulinum toxin type A in relieving pain in tennis elbow at 4 wks after injection. Because botulinum toxin injection did not relieve pain significantly but is associated with weakness, the muscle weakness caused by botulinum toxin is unlikely to be the sole mechanism of the pain relief observed in previous studies.