Total Ankle Arthroplasty With Anatomic Lateral Ankle Stabilization (ATLAS)?

A retrospective case series in the Journal of Foot & Ankle Surgery, “Total Ankle Arthroplasty With Anatomic Lateral Ankle Stabilization (ATLAS) in Moderate and Severe Pre-operative Varus Alignment,” offers an anatomic reconstruction technique of the anterior talofibular and calcaneofibular ligaments, using a synthetic biomaterial fabricated from wet-spun fibers of polycaprolactone-based polyurethane urea.

The material

The synthetic biomaterial Artelon, manufactured by International Life Sciences, is unique in that it features a high strength, load sharing, permeable material affording a non-permanent support matrix; which gradually dissolves over 5 to 6 years as it is replaced by host tissue. The graft is purported to have advantages over traditional allograft.

The technique

In a nutshell, ATLAS involves anatomically reconstructing the lateral ankle ligaments using graft, followed by an imbrication/advancement of the native host tissues, including the inferior extensor retinaculum, to the anterior surface of the fibula. One could think of it as a “Better Brostrom-Gould.”

The summary

The series details the early radiographic and clinical outcomes of seven ankles that underwent TAA with INBONE-2 and ATLAS using synthetic graft for instability in moderate and severe pre-operative varus alignment. A minimum of one year postoperative follow-up was required (mean 13.3 months, range 12-15).

Overall, survivorship for INBONE-2 with ATLAS was 100%, and recurrent instability was not observed. Coronal alignment improved significantly from 17.7 ± 9.3 (range, 10.1-33.6) to 2.3 ± 1.2 (range, 0.9-4.4) degrees (p<0.006), and all ankles achieved neutral alignment in a single stage. No revisions or re-operations were performed.

The takeaway

ATLAS using synthetic graft may have merit. However, we need comparative studies between ATLAS and other instability repair techniques – namely, the Broström-Gould.