Efficacy of total ankle replacement with meniscal-bearing devices: a systematic review and meta-analysis

Introduction

The reputation of total ankle arthroplasty for treating end-stage ankle arthritis of different origin is dubious. Newer generation meniscal-bearing prostheses may have overcome the known problems with earlier implants. There is, however, no systematic approach to the available scientific evidence allowing for a critical appraisal of their benefits and risks.

Materials and methods

We conducted a systematic review meta-analysis of studies exploring the efficacy of three-component total ankle prostheses. We demanded a minimum sample size of 20 subjects, at least 1 year of follow-up, and a clinically relevant study endpoint (for example, results of ankle scoring, ranges of motion [ROM], complications, and survival rates). We identified citations by electronic medical databases and a manual search. We made no restrictions for language. We used an eight-point quality scale to appraise methodological standards, and modeled outcomes by random-effects meta-regression analysis.

Results

Eighteen of 1830 citations including 1086 patients fulfilled our eligibility criteria. Studies met a median of four quality items (interquartile range 2–5). Outcome estimates did not depend on methodological quality. There was no evidence of strong heterogeneity or publication bias. With standardized 100-point ankle and hindfoot scores, formal data pooling was possible for 10 trials ( n =497), showing a mean improvement of 45.2 points (95% confidence interval [CI] 39.3–51.1). Overall ROM improved slightly (6.3°, 95%CI 2.2–10.5°). Weighted complication rates ranged from 1.6% (deep infections) to 14.7% (impingement). Secondary surgery had to be performed in 12.5%, whereas secondary arthrodesis was necessary in 6.3%. The weighted 5-year prosthesis survival rate averaged 90.6%.

Conclusions

Ankle arthroplasty improves pain and joint mobility in end-stage ankle arthritis. Its performance in comparison to the current reference standard (that is, ankle fusion) remains to be defined in a properly designed randomized trial.