907 Total Ankle Arthroplasty Versus Arthroscopic Ankle Arthrodesis: A Novel Comparison of Clinical Outcomes and Cost-Utility

Abstract

Abstract Aim End-stage ankle arthritis poses numerous healthcare challenges, not least given its high prevalence but also significant limitations in treatment modality. This study compares functional outcomes following total ankle arthroplasty (TAR) versus arthroscopic ankle arthrodesis (AAA). Secondary objectives were to compare complication rates and perform a health economic analysis to estimate cost-effectiveness to the NHS. Method A prospective, single centre cohort study of TAR versus AAA in patients diagnosed with end-stage ankle osteoarthritis between 2015 and 2020 with homogenous characteristics. Primary outcomes were assessed through comparing Manchester-Oxford Foot Questionnaire (MoxFQ) scores taken pre-operatively and at specific intervals post-treatment up to one year. A cost-utility analysis via decision tree modelling was performed to derive an incremental cost effectiveness ratio (ICER). Results The study involved 42 patients. TAR (22 patients) demonstrated a better functional improvement following cast removal at 3 months (Ẋ = 19.1 [TAR]/ 7.4 [AAA], p= 0.044, CI 95%) and 6 months (Ẋ= 26.1 [TAR]/ 11.5 [AA], p= 0.031, CI 95%). The average improvement of MoxFQ scores over the study was greater following TAR. Values derived from cost-utility analysis produced an ICER of £8,639.51/QALY (quality of life year) for TAR implying that the procedure is cost-effective compared to AAA with respect to the NICE treatment threshold of £20,000/QALY. Conclusions TAR provided improved patient reported outcome scores following cast removal. Although overall treatment costs are greater with TAR, reduced complications and better functional outcomes demonstrated greater economic benefit with TAR compared to AAA.