Limited Evidence for Biological Adjuvants in Hindfoot Arthrodesis: A Systematic Review and Meta- Analysis of Clinical Comparative Studies

CATEGORY: Hindfoot; Ankle; Ankle Arthritis; Basic Sciences/Biologics; Trauma INTRODUCTION/PURPOSE: The purpose of this study was to evaluate the efficacy of biological adjuvants in hindfoot arthrodesis. METHODS: A systematic review of the PubMed and Embase databases was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using specific search terms and eligibility criteria. Assessment of evidence was three-fold: level of evidence by criteria published by The Journal of Bone & Joint Surgery, quality of evidence by the Newcastle-Ottawa scale and conflicts of interest. Meta-analysis was performed by fixed-effects models for studies of low heterogeneity (I2 <25%) and random-effects models for studies of moderate to high heterogeneity (I2 >=25%). RESULTS: Hindfeet totaled 1579 patients as protocol and 1503 patients per protocol. Final reported mean follow-up ranged from 2.8 months to 43 months. Twelve of the 17 included studies were comprised of patients with comorbidities associated with reduced healing capacity. Based on the random-effects model for non-union rates for autograft versus allograft, the risk ratio was 0.82 (95% CI, 0.13 to 5.21; I2 = 56%; p = 0.83) in favour of lower non-union rates for autograft and for autograft versus rhPDGF/ß-TCP, the risk ratio was 0.90 (95% CI, 0.74 to 1.10; I2 = 59%; p = 0.30) in favour of lower non-union rates for rhPDGF/ß-TCP. CONCLUSION: There is a lack of data to support the meaningful use of biological adjuvants compared to autograft/allograft for hindfoot arthrodesis. The meta-analysis favoured the use of autograft when compared to allograft, but favoured rhPDGF/ß-TCP instead when compared to autograft in the short-term follow-up.