The utility of botulinum toxin A in the repair of distal biceps tendon ruptures

Purpose: The purpose of our study is to report the outcomes and complications in patients who underwent distal biceps tendon repair with the use of Botulinum toxin A (BoNT-A) as an adjunct to surgery.

Methods: A retrospective review of 14 patients who underwent 15 distal biceps tendon repairs was performed. All repaired tendons had their correlating muscle bellies injected intraoperatively with a mixture of 100U of BoNT-A and 10 ml of normal saline. Each patient was evaluated for surgical and post-operative complications and followed with Disabilities of the Arm, Shoulder and Hand (DASH) Disability Scores.

Results: The cohort was exclusively male, 14/14 (100%). The mean age at procedure was 52.1 years (range: 29-65 years). Types of injuries repaired included: 12 acute biceps tendon ruptures, one chronic partial (> 50% of tendon) biceps tear, and two chronic biceps ruptures. Average final follow-up was 32.9 months (SD: 19.6; range: 7.07-61.72). Average time to repair of chronic injury was 5.75 months (range: 2-12 months). There were no intraoperative complications, and all patients were discharged home on the day of surgery. Average DASH score at latest follow-up was 4.9 (range: 0.0-12.5). All patients had return of function of paralyzed muscle prior to final follow-up. One patient required an incision and drainage for a deep infection 1 week post-operatively, without any further complications. Another patient required operative removal of heterotopic ossification located around the tendon fixation site, which was the result of a superficial infection treated with antibiotics 2 weeks post-operatively. This patient later healed with improvement in supination/pronation range-of-motion and no further complications.

Conclusions: Injection of BoNT-A is safe and effective to protect distal biceps tendon repair during the early phases of bone-tendon healing.

Clinical relevance: BoNT-A may is safe and effective to protect distal biceps tendon repair. The utility of BoNT-A as an adjunct to surgical repair may be applicable to acute or chronic tears as well as repairs in the non-compliant patient without decreases in functional scores after return of function of the biceps muscle.

Level of evidence: Level 4.