abs: Bone Lesions and Edema on Equine Stifle MRI
_{The Joint Disease Challenge – Emphasis on the Stifle}

Bone edema (BE) is a rarely described MRI-based diagnosis.Thus, we report on incidence/location of BE and delineate therapeutic consequences after stifle-MRI.We hypothesized, that BE are (1) less frequently observed,(2) mainly detected in acute/subacute injuries and (3) associated with concurrent pathology.Therefore, MRI will assist in management of BE-associated lameness.Medical records of 164 confirmed stifle lameness, that underwent MRI were reviewed for breed/age/gender/clinical findings, degree/duration of lameness,MRI-anesthesia time/-findings and treatment/management.MRI was performed in dorsal recumbency and different sequences/several planes were acquired.Horses with accessible, concurrent pathology underwent subsequent arthroscopic exploration.MR-examinations were completed in average time of 67min without problems.BE were less frequently observed as compared to soft tissue lesions.Proximal tibiae and patella were affected in 14% of horses predominantly after acute/subacute injuries.Although BE were mostly recorded as sole pathology, concurrent joint effusion and cruciate desmopathy was frequently noted.Degree/duration of lameness and time to presentation varied. Logically, BE remained undetected arthroscopically, but all concurrent/accessible/superficial soft tissue lesions were revised successfully.In contrast, intralesional soft tissue degenerations were unreliably detected in arthroscopy as compared to MRI.Although meniscal and cruciate ligament flexibility appeared reduced while probing, consistent prognostic staging was impossible arthroscopically.BE are less frequently observed as compared to other stifle lesions, are mainly observed in acute/subacute injuries and can occur with concurrent pathology.Retrospective nature of this study is a limitation.Combination of MRI with subsequent arthroscopy is a save/promising approach for global understanding of stifle pathology/management/treatment/prognosis.