The gastrocnemiofibular ligament: A new, more anatomically accurate name for the fabellofibular ligament—An original magnetic resonance imaging study and meta‐analysis

INTRODUCTION: The fabellofibular ligament (FFL) is a component of the posterolateral corner (PLC) of the knee and is an anatomically variable static stabilizer. Several investigations have reported prevalence rates for the FFL among their subjects, but no overall prevalence rate has been reported. MATERIALS AND METHODS: We conducted a meta-analysis of all relevant studies reporting prevalence rates of the FFL according to PRISMA and AQUA guidelines and pooled prevalence data using MetaXL 5.3. We also conducted a retroactive magnetic resonance imaging (MRI) study of 100 knees to assess FFL and fabella prevalence. RESULTS: Twenty-one studies (from 18 articles) and our MRI data were used in this meta-analysis (n = 1,176 knees). The pooled prevalence estimate (PPE) for FFL absence was 37.4% (95% confidence interval [CI], 24.5-51.3%). When divided by continent, PPEs of FFL absence were 31.5% (95% CI, 1.4-72.7%), 58.2% (95% CI, 44.1-71.6%), and 29.0% (95% CI, 14.7-45.7%) for North American, European, and Asian subjects, respectively. Cadaveric and MRI studies showed PPEs of FFL absence of 31.5% and 49.7%, respectively. Our MRI results showed PPEs of FFL and fabella absences of 42.0 and 80.0%, respectively. CONCLUSIONS: Understanding prevalence rates and anatomical geometry of the FFL will assist surgeons in repairing PLC injuries. Our MRI data and previous studies suggest the FFL is frequently present in knees lacking a fabella. Based on the observations of this study, we propose the ligament be renamed the gastrocnemiofibular ligament.