SLR - January 2010 - Katherine E. Chou
Reference:
De Aguiar, G., Chait, L.A., Schultz, D., Bleloch, S., Theron, A., Snijman, C.N., Ching, V. (2009). Chemoprotection of Flexor Tendon Repairs Using Botulinum Toxin. Plastic and Reconstructive Surgery, 124(1), 201-209.
Scientific Literature Reviews
Reviewed by: Katherine E. Chou, DPM
Residency Program: Kaiser North Bay Consortium, Vallejo
Podiatric Relevance:
Podiatric surgeons commonly repair ruptured tendons and electively transfer tendons in the lower extremity. One major postoperative drawback is the necessary immobilization used to protect the repair or transfer. Prolonged immobilization can cause joint stiffness and tendon adhesion that can be difficult to overcome, even with physical therapy. The selective use of botulinum toxin could potentially reduce or eliminate these sequelae and improve the functional outcome of tendon repairs and transfers.
Methods:
A three year prospective study of acute flexor tendon injuries in the hand was compared retrospectively to a matched cohort. The matched cohort of 53 patients (104 injuries), Group B, had the same surgeon, surgical technique, rehabilitation protocols, and therapists. The prospective group of 18 patients (34 injuries), Group A, all had modified Kessler tendon repair with stainless steel wire markers placed intra-tendinously on either side of the coaptation site which were measured for later comparison during mobilization and follow-up studies. They all had intramuscular botulinum injections under electromyographic control into the corresponding proximal flexor muscle belly within 48 hours after surgery. A standardized, closely controlled rehabilitation period was followed for all patients, based on the physiology of the botulinum toxin and the known pattern of healing. Range of motion was assessed for the prospective group at 2,4,6 and 12 weeks and at 6, 12 and 18 months. Both groups were assessed at 18 months post operatively according to the criteria of the Committee on Tendon Injuries as either excellent, good, fair or poor.
Results:
The use of botulinum toxin to allow early range of motion resulted in statistically significant improved outcomes in regards to range of motion for all results: excellent, good, fair and poor. There was a statistically significant association at the 5% level between groups A and B in the excellent-good and fair-poor range of motion categories. When stratified into separate groups, 94% compared to 84% of patients had excellent results and were statistically significant at the 5% confidence level. 6% of patients had good results in both groups and were statistically significant at the 10% confidence level. Zero compared to 8% of patients had fair results and were statistically significant at the 1% confidence level. Zero compared to 6% of patients had poor results and were statistically significant at the 1% confidence level.
Conclusions:
Botulinum toxin results in a temporary dose-dependent paralysis of skeletal muscle by acting on the neuromuscular junction. These effects can last for 12-16 weeks, but the motor end plates recover completely and normal neurotransmission resumes. The use of botulinum chemoprotection of primary flexor tendons in the hand offers the advantages of protected early active mobilization with reduced risk of gap formation or rupture. Although this technique may have more limited use in foot and ankle surgery compared to hand surgery, the use of botulinum chemoprotection may improve overall outcomes in foot and ankle surgery.