Review of Use of Amniotic Membrane Allograft in Total Ankle Replacements

Abstract

Category: Ankle Arthritis Introduction/Purpose: Wound complications after total ankle replacement (TAR) lead to increased postoperative morbidity with lasting consequences. Previous studies demonstrate delayed wound healing in 6.6% to 28% of all TARs. Soft tissue breakdown along the anterior incision can cause exposure of anterior tendons and the implants. In addition, adhesions of the extensor tendons can develop causing significant morbidity. Recent publications advocate for the use of dehydrated human amnion/chorion membrane allograft (dHACM) during closure of anterior ankle incisions during TAR. dHACM is shown to promote increased epithelial cell proliferation, recruitment, and differentiation and reduce the likelihood of tendon adhesions. The goal of this study was to review the use of dHACMs in TARs and to investigate the number and type of postoperative wound complications including extensor tendon adhesions. Methods: We retrospectively reviewed 92 TARs performed between April, 2016 through August, 2018 by two board certified, fellowship trained foot and ankle orthopaedic surgeons. A standard anterior approach was done in all cases. All TARs had dHACM graft placed deep to the tibialis anterior and extensor longus tendon and along the extensor retinaculum prior to final closure of the wound. Upon data review, we identified the subset of patients who had anterior wound dehiscence postoperatively requiring an additional procedure(s) for wound coverage. We compared the demographics, medical comorbidities, and operative characteristics of those with and without perioperative wound complications. Results: 12 patients who underwent TARs sustained wound dehiscence below the subcutaneous tissue and required operative intervention (13%). Of these 12 cases, 5 required bipedical or rotational fasciocutaneous flap coverage (5.4%), 6 required less extensive soft tissue surgery (6.5%) and one case involved a deep periprosthetic infection that resulted in explant and antibiotic spacer placement (1.1%). 6 of the 12 cases required a split thickness skin graft application (6.5%) and 2 cases required tenolysis of extensor tendon adhesions (2.2%). Normal excursion of extensor tendons was seen in 90 patients (97.8%). Except for the one infected ankle, there were no cases with wound dehiscence that communicated with the joint. There were no statistically significant differences in medical comorbidities/operative characteristics between patients with wound complications and those without. Conclusion: Wound complications after total ankle replacements often lead to poor long-term outcomes for patients. Our data suggests that the application of the amniotic membrane allograft and its inherent healing potential decreases postoperative tendon adhesions and significant wound dehiscence. This may lead to less deep wound infections that communicate with the joint and may be protective against total ankle replacement failures due to these complications.