Aims

Implant failure has become more common as the number of primary total ankle arthroplasties (TAAs) performed has increased. Although revision arthroplasty has gained attention for functional preservation, the long-term results remain unclear. This study aimed to assess the long-term outcomes of revision TAA using a mobile-bearing prosthesis in a considerably large cohort; the risk factors for failure were also determined.

Aims

Despite the increasing numbers of ankle arthroplasties, there are limited studies on their survival and comparisons between different implants. The primary aim of this study was to determine the failure rates of primary ankle arthroplasties commonly used in the UK.

Aims. We report the medium-term outcomes of a consecutive series of 118 Zenith total ankle arthroplasties (TAAs) from a single, non-designer centre. Methods. Between December 2010 and May 2016, 118 consecutive Zenith prostheses were implanted in 114 patients. Demographic, clinical, and patient-reported outcome measures (PROMs) data were collected. The endpoint of the study was failure of the implant requiring revision of one or all of the components. Kaplan-Meier survival curves were generated with 95% confidence intervals (CIs) and the rate of failure calculated for each year. Results. Eight patients (ten ankles) died during follow-up, but none required revision. Of the surviving 106 patients (108 ankles: rheumatoid arthritis (RA), n = 15; osteoarthritis (OA), n = 93), 38 were women and 68 were men, with a mean age of 68.2 years (48 to 86) at the time of surgery. Mean follow-up was 5.1 years (2.1 to 9.0). A total of ten implants failed (8.5%), thus requiring revision. The implant survival at seven years, using revision as an endpoint, was 88.2% (95% CI 100% to 72.9%). There was a mean improvement in Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) from 85.0 to 32.8 and visual analogue scale (VAS) scores from 7.0 to 3.2, and overall satisfaction was 89%. The three commonest complications were malleolar fracture (14.4%, n = 17), wound healing (13.6%, n = 16), and superficial infection (12.7%, n = 15). The commonest reason for revision was aseptic loosening. No patients in our study were revised for deep infection. Conclusion. Our results show that Zenith survival rates are comparable with those in the literature for other implants and in the National Joint Registry (NJR). Overall patient satisfaction was high as were functional outcomes. However, the data highlight potential complications associated with this surgery. The authors believe that these figures support ankle arthroplasty as an option in the treatment of ankle arthritis. Cite this article: Bone Joint J 2021;103-B(4):696–703

We present the outcomes in 38 consecutive patients who had total ankle replacement using the Ankle Evolution System with a minimum follow-up of four years. Pain and function were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) score and regular standardised anteroposterior and lateral weight-bearing radiographs were obtained. Patient satisfaction and complications were recorded and the survival of the implants was demonstrated by the Kaplan-Meier method.

The mean follow-up was for 57.8 months (48 to 80). The cumulative survival rate at six years was 94.7% (95% confidence interval 80.3 to 98.7). The mean total AOFAS score was 88.1 (53 to 100). The mean score for pain was 35.8 (20 to 40). Ten patients presented with edge-loading of whom nine had corrective surgery. Two ankles were revised, one to an arthrodesis and the other to replace the tibial component. Nine patients showed radiological evidence of osteolysis. They had minimal non-progressive symptoms and further surgery was not undertaken. Nevertheless, the concerns about osteolysis led to the implant being withdrawn by the manufacturer.

The medium-term results of the ankle evolution system ankle replacement are satisfactory with high patient satisfaction, but the rate of osteolysis is of some concern. The long-term benefit of this procedure has yet to be determined.

Between 2002 and 2008, 130 consecutive ankles were replaced with an hydroxyapatite (HA) and titanium-HA-coated Ankle Evolutive System total ankle prosthesis. Plain radiographs were analysed by two independent observers. Osteolytic lesions were classified by their size and location, with cavities > 10 mm in diameter considered to be ‘marked’. CT scanning was undertaken in all patients with marked osteolysis seen on the plain radiographs.

Osteolytic lesions were seen on the plain films in 48 (37%) and marked lesions in 27 (21%) ankles. The risk for osteolysis was found to be 3.1 (95% confidence interval 1.6 to 5.9) times higher with implants with Ti-HA porous coating.

Care should be taken with ankle arthroplasty until more is known about the reasons for these severe osteolyses.

We carried out 123 consecutive total ankle replacements in 111 patients with a mean follow-up of four years (2 to 8). Patients with a hindfoot deformity of up to 10° (group A, 91 ankles) were compared with those with a deformity of 11° to 30° (group B, 32 ankles). There were 18 failures (14.6%), with no significant difference in survival between groups A and B. The clinical outcome as measured by the post-operative American Orthopaedic Foot and Ankle Surgeons score was significantly better in group B (p = 0.036). There was no difference between the groups regarding the post-operative range of movement and complications. Correction of the hindfoot deformity was achieved to within 5° of neutral in 27 ankles (84%) of group B patients. However, gross instability was the most common mode of failure in group B. This was not adequately corrected by reconstruction of the lateral ligament.

Total ankle replacement can safely be performed in patients with a hindfoot deformity of up to 30°. The importance of adequate correction of alignment and instability is highlighted.

We describe the results of a randomised, prospective study of 200 ankle replacements carried out between March 2000 and July 2003 at a single centre to compare the Buechel-Pappas (BP) and the Scandinavian Total Ankle Replacement (STAR) implant with a minimum follow-up of 36 months. The two prostheses were similar in design consisting of three components with a meniscal polyethylene bearing which was highly congruent on its planar tibial surface and on its curved talar surface. However, the designs were markedly different with respect to the geometry of the articular surface of the talus and its overall shape.

A total of 16 ankles (18%) was revised, of which 12 were from the BP group and four of the STAR group. The six-year survivorship of the BP design was 79% (95% confidence interval (CI) 63.4 to 88.5 and of the STAR 95% (95% CI 87.2 to 98.1). The difference did not reach statistical significance (p = 0.09). However, varus or valgus deformity before surgery did have a significant effect) (p = 0.02) on survivorship in both groups, with the likelihood of revision being directly proportional to the size of the angular deformity. Our findings support previous studies which suggested that total ankle replacement should be undertaken with extreme caution in the presence of marked varus or valgus deformity.

We describe the medium-term results of a prospective study of 200 total ankle replacements at a single-centre using the Scandinavian Total Ankle Replacement. A total of 24 ankles (12%) have been revised, 20 by fusion and four by further replacement and 27 patients (33 ankles) have died. All the surviving patients were seen at a minimum of five years after operation. The five-year survival was 93.3% (95% confidence interval (CI) 89.8 to 96.8) and the ten-year survival 80.3% (95% CI 71.0 to 89.6).

Anterior subluxation of the talus, often seen on the lateral radiograph in osteoarthritic ankles, was corrected and, in most instances, the anatomical alignment was restored by total ankle replacement. The orientation of the tibial component, as seen on the lateral radiograph, also affects the position of the talus and if not correct can hold the talus in an abnormal anterior position. Subtalar arthritis may continue to progress after total ankle replacement. Our results are similar to those published previously.