Total ankle replacement: is pre-operative varus deformity a predictor of poor survival rate and clinical and radiological outcomes?

PURPOSE: The objective of this study was to compare survival rate and clinical and radiological outcomes of a cementless mobile-bearing total ankle replacement (TAR) between two groups of patients, affected by end-stage ankle arthritis, with or without a pre-operative varus deformity.

METHODS: A total of 81 patients (81 ankles) were included in the study and divided in two groups. Group A, "varus" group, includes 11 patients with pre-operative varus deformity of more than 10 ° and group B, "neutral" group, includes 70 patients, with a varus/valgus deformity of less than 10 °. American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), and Short Form (SF)-12 score were used to compare clinical outcomes. Radiological parameters, complications, and survival rate at last follow-up were also recorded.

RESULTS: In both groups, all clinical and radiological parameters improved after surgery (p < 0.05) without statistically significant difference. Complications were similar between two groups. Overall in three cases, an implant revision was necessary: 1 in group A (9%) at 3.1 years follow-up and 2 (3%) in group B at 3.8 years, without statistically significant difference (p > 0.001).

CONCLUSIONS: Severe varus malalignment should not be considered a contraindication for a mobile-bearing TAR. Nevertheless, TAR in severe deformity should be performed only by experienced surgeons.