Comparison Between Steroid and 2 Different Sites of Botulinum Toxin Injection in the Treatment of Lateral Epicondylalgia: A Randomized, Double-Blind, Active Drug-Controlled Pilot Study.

[OBJECTIVE] To compare the effects of 2 different injection sites of low doses of botulinum toxin type A with steroid in treating lateral epicondylalgia.

[DESIGN] Double-blind, randomized, active drug-controlled trial.

[SETTING] Tertiary medical center.

[PARTICIPANTS] Patients with lateral epicondylalgia for >6 months were recruited from a hospital-based outpatient population (N=26). A total of 66 patients were approached, and 40 were excluded. No participant withdrew because of adverse effects.

[INTERVENTIONS] Patients were randomly assigned into 3 groups: (1) botulinum toxin epic group (n=8), who received 20U of botulinum toxin injection into the lateral epicondyle; (2) botulinum toxin tend group (n=7), who received 20U of botulinum toxin injected into tender points of muscles; and (3) steroid group (n=11), who received 40mg of triamcinolone acetonide injected into the lateral epicondyle.

[MAIN OUTCOME MEASURES] A visual analog scale, a dynamometer, and the Patient-Rated Tennis Elbow Evaluation were used to evaluate the perception of pain, maximal grip strength, and functional status, respectively. Outcome measures were assessed before intervention and at 4, 8, 12, and 16 weeks after treatment. The primary outcome measure was a visual analog scale.

[RESULTS] At 4 weeks after injection, the steroid group was superior to the botulinum toxin tend group in improvement on the visual analog scale (P=.006), grip strength (P=.03), and Patient-Rated Tennis Elbow Evaluation (P=.02). However, these differences were not observed at the 8-, 12-, and 16-week follow-up assessments. There was no significant difference between the steroid and botulinum toxin epic groups.

[CONCLUSIONS] Injections with botulinum toxin and steroid effectively reduced pain and improved upper limb function in patients with lateral epicondylalgia for at least 16 weeks. The onset of effect was earlier in the steroid and botulinum toxin epic groups than in the botulinum toxin tend group.