Abstract
Background
Despite the fact that 4th generation Total Ankle Replacement implanted from lateral transmalleolar approach is present on the market from 2013, a small number of reports discussing its results are available in the literature.
The aim of this study is to describe the early clinical and radiological outcomes of patients who underwent ankle replacement with use of Zimmer Ankle Trabecular Metal.
Methods
Between June 2015 and November 2020 a group of 26 patients underwent lateral approach total ankle replacement with Zimmer ATM. The standard clinical assessment of the American Orthopaedic Foot and Ankle (AOFAS) score, the Visual Analogue Scale (VAS) and Foot and Ankle Ability Measure – Activities of Daily Living (FAAM-ADL) score were collected pre- and post-operatively, with minimal follow-up of 12 months. The radiological outcomes were based on standard weight-bearing antero-posterior, lateral and LAV or HAV foot and ankle radiographs taken before the surgery, 6 months postop and during the last visit.
Results
Preoperatively, the mean AOFAS and VAS score was respectively 43.4 and 6.3 and at the last follow-up control was 80.2 and 1.5. The mean preoperative FAAM-ADL score was 34.2 and at the last follow-up visit was 69.8.
Radiological assessment showed good orientation of the implants. The mean ALDTA and ADTA score were respectively 81.9°, 80.2° and had improved after the surgery to mean value “a”= 89.9°, “ß”= 85.3 and “?”= 17.7. The mean TT-ratio improved from 30.1 preoperatively to 37.6 at the las follow-up.
In 2 cases early complications occurred: 1 (3.8%) fracture of the medial malleolus healed with prolonged immobilisation in plaster cast and 1 (3.8%) loosening of the tibial component requiring revision and replacement of the component. In 1 (3.8%) case there was a late deep infection (20 months postop). The TAR was removed and in the second stage arthrodesis with autologous graft was performed.
14 patients (53%) had to undergo additional procedures such calcaneal osteotomy, subtalar arthrodesis, tibial osteotomy, Achilles tendon elongation, Cotton osteotomy or ATFL reconstruction because of complete lack of ligament remnant. All procedures were performed without tourniquet; only 1 patient needed the blood transfusion.
Conclusions
The early results of the lateral approach total ankle replacement show high level of patient satisfaction and the possibility of anatomical restoration of ankle joint alignment. However, it is necessary to extend the observation period.
Keywords: Ankle arthroplasty, Ankle osteoarthritis, Pain, Total ankle replacement, Lateral ankle approach.