OBJECTIVE: The purpose of this study was to determine the prevalence of and relevant findings associated with the accessory anterolateral talar facet, which may have a role in talocalcaneal impingement and sinus tarsi syndrome, on ankle MR images of persons with and those without symptoms. SUBJECTS AND METHODS: In this case-control study, three observers independently reviewed 1.5-T or 3-T MR images of 110 ankles with symptoms in 100 consecutively registered patients (age range, 16-79 years; mean, 41.5 years) and limited 1.5-T MR images of 104 age-, sex-, and side-matched ankles in 104 volunteers without symptoms for the presence of an accessory anterolateral talar facet, calcaneal cortical thickness, subjacent talar or calcaneal cystic and bone marrow edema-like changes at the angle of Gissane, and sinus tarsi fat obliteration. RESULTS: An accessory anterolateral talar facet was present in 36 (32.7%) ankles with symptoms versus 27 (26.0%) symptom-free ankles (p = 0.297). Interobserver agreement was almost perfect (κ = 0.851; 95% CI, 0.772-0.929) for the detection of accessory anterolateral talar facet and substantial for the detection of sinus tarsi fat obliteration (κ = 0.671; 95% CI, 0.427-0.915). The angle of Gissane was significantly smaller in persons with an accessory anterolateral talar facet, either with or without symptoms (p < 0.0001). Subjacent talar (p = 0.003) and calcaneal (p = 0.033) bone marrow edema-like change and sinus tarsi fat obliteration (p = 0.034) were significantly more frequent in persons with accessory anterolateral talar facet, but chronic reactive osseous changes at the angle of Gissane were not (p > 0.05). CONCLUSION: The higher prevalence of the MRI finding of an accessory anterolateral talar facet in ankles with symptoms is not statistically significant. This facet may be associated with subjacent talar bone marrow edema-like change on MR images of individuals with and those without symptoms and with sinus tarsi fat obliteration in individuals with symptoms.
OBJECTIVE: The purpose of this study was to determine the prevalence of and relevant findings associated with the accessory anterolateral talar facet, which may have a role in talocalcaneal impingement and sinus tarsi syndrome, on ankle MR images of persons with and those without symptoms. SUBJECTS AND METHODS: In this case-control study, three observers independently reviewed 1.5-T or 3-T MR images of 110 ankles with symptoms in 100 consecutively registered patients (age range, 16-79 years; mean, 41.5 years) and limited 1.5-T MR images of 104 age-, sex-, and side-matched ankles in 104 volunteers without symptoms for the presence of an accessory anterolateral talar facet, calcaneal cortical thickness, subjacent talar or calcaneal cystic and bone marrow edema-like changes at the angle of Gissane, and sinus tarsi fat obliteration. RESULTS: An accessory anterolateral talar facet was present in 36 (32.7%) ankles with symptoms versus 27 (26.0%) symptom-free ankles (p = 0.297). Interobserver agreement was almost perfect (κ = 0.851; 95% CI, 0.772-0.929) for the detection of accessory anterolateral talar facet and substantial for the detection of sinus tarsi fat obliteration (κ = 0.671; 95% CI, 0.427-0.915). The angle of Gissane was significantly smaller in persons with an accessory anterolateral talar facet, either with or without symptoms (p < 0.0001). Subjacent talar (p = 0.003) and calcaneal (p = 0.033) bone marrow edema-like change and sinus tarsi fat obliteration (p = 0.034) were significantly more frequent in persons with accessory anterolateral talar facet, but chronic reactive osseous changes at the angle of Gissane were not (p > 0.05). CONCLUSION: The higher prevalence of the MRI finding of an accessory anterolateral talar facet in ankles with symptoms is not statistically significant. This facet may be associated with subjacent talar bone marrow edema-like change on MR images of individuals with and those without symptoms and with sinus tarsi fat obliteration in individuals with symptoms.