SHORT-TERM RESULTS OF TOTAL ANKLE ARTHROPLASTY WITH USE OF A NOVEL MOBILE-BEARING DESIGN

Abstract

Introduction: The aim of this study was to evaluate the short-term results with use of a novel mobile-bearing design for total ankle arthroplasty (TAA).

Methods: A consecutive series of 70 primary TAA in 69 patients (37 women, 32 men), replaced between 2004 and 2007 with the Ceramic Coated Implant (CCI) Evolution (Van Straten, Nieuwegein, Netherlands) prosthesis was studied prospectively. Diagnosis was: postfracture arthritis 17, instability arthritis 21 (13 combined with a varus deformity of 10°–25°), rheumatoid arthritis 25, osteoarthritis 6 and haemochromatosis 1. Mean age at surgery was 59.3 years (range 30–84). AOFAS ankle score and range of motion were assessed and survival curves calculated.

Results: At follow-up, in 2008, 2 patients had deceased. Six TAA had failed for the following reasons: deep infection 1, secondary fracture 1, and aseptic loosening of the tibial component 4 (in 2 due to an increased anterior slope of the tibial component). All four mechanical failures occurred in patients with instability arthritis. Three-year survival with revision for any reason as an endpoint was 0.90 (SE 0.04). No talar components have been revised.

AOFAS score increased from 35.6 (SD 14.4) preoperative to 82.3 at FU (p< 0.05), dorsiflexion increased from 4.9° to 8.6° (p< 0.05), plantarflexion from 27.4° to 30.9° (n.s.).

Discussion and Conclusions: Good results were obtained in patients with rheumatoid arthritis and post-fracture arthritis. Mechanical failures of the tibial component occurred in instability arthritis and were related to malposition of the tibial component. No mechanical problems related to the talar component have been encountered.