Prospective Clinical-Surgical Evaluation of Safety and Efficacy of Acellular Human-Dermis in the Repair of Tendons-Ligaments of the Foot/Ankle

Abstract

Category: Sports Introduction/Purpose: Injury with subsequent surgical repair to the Achilles and Posterior-Tibial tendon as well as the lateral ankle are common procedures for the foot and ankle surgeon. Surgical repair provides the best chance for restoration of strength, power, and function of the muscle-tendon-ligament and bone complex. Healing time is variable, and a means of reducing immobilization time, pain and improving function would be beneficial. Various biomaterials have been used to supplement these repairs with acellular human-dermis showing great promise in many retrospective analysis performed in the orthopedic literature. The purpose of this study is to examine safety and efficacy, in a prospective model, of acellular human-dermis to supplement soft tissue repair in the foot and ankle. Methods: This is a prospective, single-center WIRB-approved trial evaluating a sterile acellular human-dermis (AHD) to supplement the repair of the Achilles tendon, Posterior-Tibial tendon and lateral-ankle ligaments. AHD was placed directly over the repaired soft-tissue structure during the surgical procedure and sewed into place with 2-0 fiber-reinforced suture in lateral trap fashion by a single surgeon. The primary objective is to establish that AHD is efficacious in the repair of soft tissue structures of the foot and ankle. The secondary objectives are to show the safety and lack of soft-tissue reaction. VAS pain-scales, AOFAS- hindfoot score and Sf-36 were evaluated at intervals up to 12 months. An ultrasound was performed of the soft tissue repaired at the final visit to establish integrity and lack of fluid or inflammation around the soft tissue repair patch. A modified intent-to-treat analysis was performed and general linear-modeling with repeated measures was used to analyze the data. Results: 24 consecutive-patients were screened with 23 patients meeting inclusion/exclusion criteria(11-Achilles repairs, 7-lateral- ankle stabilizations and 5-Posterior-Tibial tendon repairs). In all groups there was a very large change between pre-operative evaluation of pain(VAS), AOFAS hindfoot-scale-score, and SF-36 scores over-time(Figures 1a-c). When all groups were combined the change in VAS was statistically significant with a partial-η2 of 0.8, a power of 100%(p=1.2 x 10-14), AOFAS hindfoot- scale- score was statistically significant with a partial-η2 of 0.88, a power of 100%(p=1.9 x 10-26) and the overall change in SF-36 physical component score was statistically significant with a partial- η2 of 0.87, a power of 100(p=1.3 x 10-30), indicating very-significant changes in all three scores over-time. Ultrasound at one-year showed a lack of fluid signal, with all tendons and ligaments intact. Conclusion: Use of an acellular human dermal matrix to supplement soft tissue repair in the foot and ankle is a viable option for the foot and ankle surgeon, showing clear statistically significant improvement in VAS, AOFAS hindfoot scale score and SF-36 physical component score over time. The lack fluid around the repair site and confluent tendons and ligaments confirm prior studies that show the safety and lack of inflammatory response of acellular human dermis. Larger prospective analysis should be considered to further confirm these findings