Effect of Tendon Gap Distance on Clinical Outcomes Following Nonsurgical Management of Acute Achilles Tendon Rupture: A Systematic Review and Meta-Analysis.

BACKGROUND: The prognostic value of initial tendon gap distance following acute Achilles tendon rupture (ATR) remains unclear. The present systematic review and meta-analysis aimed to investigate the effect of tendon gap distance on clinical outcomes following nonsurgical management of acute ATR. METHODS: Our review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and used PubMed, EMBASE, and Cochrane Library databases for studies investigating the influence of tendon gap distance on functional outcomes following nonsurgical management of acute ATR. Data investigated included patient demographics, functional scores, including the Achilles Tendon Rupture Score (ATRS), gap size, and rupture location. The association between tendon gap distance and functional outcomes was investigated. Additional analyses examined secondary associations among age, sex, and rupture location and functional outcomes. RESULTS: A total of eight studies comprising 288 patients with acute ATRs were included in our review. Of these, four studies met criteria for quantitative synthesis and were included in the meta-analysis. With a cutoff of 10-mm gap distance, the pooled analysis demonstrated a markedly lower ATRS in patients with a larger gap size (>10 mm versus ≤10 mm; Cohen d = -0.39; 95% CI = -0.76 to -0.02; P = 0.04). Secondary analyses revealed lower ATRS in patients older than 50 years (d = -0.70; P < 0.001) and female patients (d = -0.58; P = 0.01), whereas rupture location had no notable effect (P = 0.85). CONCLUSION: Our review demonstrated that a larger initial tendon gap is associated with lower functional outcomes following nonsurgical management of acute ATR, particularly with a cutoff of 10 mm. Furthermore, factors such as age and sex may also influence clinical outcomes. However, the result should be interpreted with caution due to heterogeneity across studies. LEVEL OF EVIDENCE: Level 3, systematic review and meta-analysis.