Revision of failed primary total ankle replacements to the Inbone 2 Total Ankle Replacement system: the Nottingham Experience

H. Salem, M. Raglan, S. Dhar

Introduction: Number of primary total ankle replacement (TAR) rises, the need for revision TAR's has also increased. Salvage procedures for failed TAR to date have ranged from ankle and TTC fusions, cement arthroplasty, attempts at further ankle replacement and below knee amputations. Clearly revision to another TAR is ideal and thus attempts continue to develop a satisfactory revision implant system. We present our experience of the Inbone 2 TAR system for revision of failed TAR from a high volume total ankle arthroplasty centre in the UK. We believe this to be the largest series of the Inbone 2 implant as a revision system worldwide, presented to-date.

Methods: We carried out a retrospective review of prospectively collected data at our institution and identified 26 patients (17M, 9F) that required revision to the Inbone 2 TAR with a mean age 66 years (51-81) between June 2016 and July 2019, the mean time to revision was 60 months (15-150) All implants were revised because of aseptic loosening. All patients were required to fill in PROMS (MOXFQ, EQ5D) and all had weight bearing X-rays at their follow up appointments at 6 weeks, 3, 6 and 12 months and then annually.

Results: A substantial improvement was noted in the clinical presentation of these revision cases as borne out by the significant improvement of their PROM scores, radiological alignment and range of movement. No lysis, cyst formation or ectopic bone was noted on x-rays at this early stage. All patients were fully mobile without walking aids. Full data will be presented at the meeting if the paper is selected.

Discussion: This very short-term review has got us excited because of the improvements noted clinically and radiologically. Whilst the procedure is complex, it does offer an opportunity to retain movement. Clearly these difficult cases will need continued follow-up.