The Bologna-Oxford ankle replacement: a case series of clinical and radiological outcomes

Abstract

Purpose: The Bologna-Oxford (BOX®) total ankle arthroplasty (TAA) is a three-component mobile-bearing implant gaining popularity in Europe. We aimed to analyse the outcomes of this TAA.

Methods: We retrospectively analysed data on 34 consecutive BOX® TAAs performed at a single centre with a mean follow-up of 58 months. Radiographic outcomes, such as periprosthetic lucency and alignment, were measured and recorded. Prospectively captured clinical scores and range of movement (ROM) were also recorded.

Results: There were significant improvements in patient-reported outcome scores recorded in the Manchester-Oxford Foot Questionnaire (MOxFQ) for pain (43.8 ± 20.2, p < 0.001), standing and walking (55.6 ± 19.8, p < 0.001), social activities (45.0 ± 26.9, p < 0.02) and visual analogue score (VAS) (3.1 ± 2.5, p < 0.001). Mean improvement in ROM postoperatively was 18.7° (p < 0.001), with post-operative dorsiflexion 8.8° (10°-25°) and plantar flexion 32.6° (20°-40°). There was evidence of asymptomatic lucency on five radiographs (15%), which was present in 10% at three years. Nine patients had complications (26%): six (18%) requiring secondary surgery and one requiring revision (3%) for infection.

Conclusions: We have demonstrated 97% survivorship at a mean of 58 months. There are maintained improvements in clinical and radiological outcomes and reoperation that are consistent with the literature.

Keywords: Alignment; Loosening; Mobile bearing; Range of movement.