第1跖趾关节损伤类型及MRI表现OA

Objective To explore the injury patterns resulting from different injury mechanisms of the first metatarsophalangeal joint(MTPJ)and to characterize their magnetic resonance imaging(MRI)features,thereby providing accurate imaging evidence for early diagnosis and treatment.Methods This retrospective study included 84 patients(84 feet)with first MTPJ injuries confirmed by surgery or clinical follow-up,with a mean age of 39.8±9.5 years.All patients underwent MR examinations.Injury patterns were analyzed according to the underlying injury mechanisms,and corresponding MRI features were evaluated.Interobserver agreement between two musculoskeletal radiologists for the diagnosis of first MTPJ injuries was assessed using Kappa statistics.Results Based on the injury mechanism,68 patients sustained plantar plate injuries caused by isolated hyperextension,6 patients had medial collateral ligament injuries resulting from isolated valgus stress,7 patients had lateral collateral ligament injuries caused by isolated varus stress,and 3 patients sustained combined valgus and hyperextension injuries.On MRI,injuries involving the central portion of the plantar plate,intersesamoid ligament,metatarsosesamoid ligament,main collateral ligament,accessory sesamoid ligament,and partial-thickness tears of the sesamophalangeal ligament were characterized by irregular morphology and focal hyperintensity on proton density-weighted fat-suppressed images.Full-thickness tears of the sesamophalangeal ligament were manifested as complete disruption of ligament continuity,with the tear extending through the entire ligament.Interobserver agreement for the diagnosis of first MTPJ injuries was good to excellent(all kappa>0.7).Conclusion MRI allows clear visualization of injury patterns and characteristic imaging findings of first MTPJ injuries and enables accurate classification of injury types.It plays an important role in the early diagnosis and precise management of first MTPJ injuries.