Aims

The purpose of this study was to determine the functional outcome and implant survivorship of mobile-bearing total ankle arthroplasty (TAA) performed by a single surgeon.

Aims

We report the long-term clinical and radiological outcomes of a consecutive series of 200 total ankle arthroplasties (TAAs, 184 patients) at a single centre using the Scandinavian Total Ankle Replacement (STAR) implants.

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 Nevertheless, the concerns about osteolysis led to the implant being withdrawn by the manufacturer.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.

In a retrospective study we compared 32 HINTEGRA total ankle replacements (TARs) and 35 Mobility TARs performed between July 2005 and May 2010, with a minimum follow-up of two years. The mean follow-up for the HINTEGRA group was 53 months (24 to 76) and for the Mobility group was 34 months (24 to 45). All procedures were performed by a single surgeon.

There was no significant difference between the two groups with regard to the mean AOFAS score, visual analogue score for pain or range of movement of the ankle at the latest follow-up. Most radiological measurements did not differ significantly between the two groups. However, the most common grade of heterotopic ossification (HO) was grade 3 in the HINTEGRA group (10 of 13 TARs, 76.9%) and grade 2 in the Mobility group (four of seven TARs, 57.1%) (p = 0.025). Although HO was more frequent in the HINTEGRA group (40.6%) than in the Mobility group (20.0%), this was not statistically significant (p = 0.065).The difference in peri-operative complications between the two groups was not significant, but intra-operative medial malleolar fractures occurred in four (11.4%) in the Mobility group; four (12.5%) in the HINTEGRA group and one TAR (2.9%) in the Mobility group failed (p = 0.185).

Cite this article: Bone Joint J 2013;95-B:1075–82.

The aim of this study was to compare the outcome of bilateral sequential total ankle replacement (TAR) with that of unilateral TAR. We reviewed 23 patients who had undergone sequential bilateral TAR under a single anaesthetic and 46 matched patients with a unilateral TAR. There were no significant pre-operative differences between the two groups in terms of age, gender, body mass index, American Society of Anaesthesiologists classification and aetiology of the osteoarthritis of the ankle. Clinical and radiological follow-up was carried out at four months, one and two years.

After four months, patients with simultaneous bilateral TAR reported a significantly higher mean pain score than those with a unilateral TAR. The mean American Orthopaedic Foot and Ankle Society hindfoot score and short-form 36 physical component summary score were better in the unilateral group. However, this difference disappeared at the one-and two-year follow-ups.

Bilateral sequential TAR under one anaesthetic can be offered to patients with bilateral severe ankle osteoarthritis. However, they should be informed of the long recovery period.

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.