External Versus Internal Fixation Techniques for Ankle Arthrodesis: A Systematic Review and Meta-analysis

Abstract

Ankle arthrodesis is an effective surgical intervention for end-stage arthritis or severe ankle joint deformity. Both internal (IF) and external fixation (EF) techniques are valid options, but there is controversy regarding the most effective technique. This study compares the safety and efficacy of EF and IF fixation techniques for ankle arthrodesis. A systematic review and meta-analysis were conducted according to the Preferred reporting items for systematic reviews and meta-analyses (PRISMA) Guidelines. A literature search of electronic databases, including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL), was performed to identify all studies directly comparing the two techniques. Both fixed and random effects models of analysis were used depending on heterogeneity. Odds of union in the EF and IF groups were comparable (OR = 0.60, CI 0.36-1.02, p = .06) however, EF was associated with greater odds of deep hardware infections (OR = 3.67, 1.97-6.83, p < .05) and amputations (OR = 3.17, CI 1.06-9.54, p = .04). Odds of revision surgery and superficial wound complications were similar between groups. EF techniques had significantly longer operation times (MD = 31.23, CI-25.11-37.34, p < .05) and intraoperative blood loss (MD = 46.31, CI-24.93-67.69, p < .05). No significant difference was noted in pain and functionality scores. IF and EF techniques have reasonable union rates with similar postoperative outcomes. However, IF patients are more likely to achieve primary union and less likely to have deep infections, being mindful that EF techniques were usually indicated for more complex cases.