Radioulnar Interosseous Ligament Diseases in Dogs: A Case Series

Abstract The aim of this study was to describe the signalment of dogs with radioulnar interosseous ligament disease and their radiographic and clinical features, and to distinguish two entities: radioulnar ischemic necrosis (RUIN) and radioulnar ligament desmopathy (RULD). This multicenter retrospective case series included data from dogs from referral centers and the Veterinary Information Network (VIN) database. Cases were included based on compatible clinical signs and radiographic findings. RUIN lesions were characterized by focal cortical lysis of the caudal aspect of the radius and the cranial aspect of the ulna. RULD lesions were characterized by smooth bone proliferation on the lateral aspect of the antebrachial bones. Among the 233 dogs included (9 referral cases, 224 from VIN), 115 had RUIN, and 118 had RULD. RUIN primarily affected small, chondrodystrophic breeds, while RULD was more common in large, nonchondrodystrophic breeds. Elbow dysplasia was a frequent comorbidity in RUIN and RULD cases. In the referral cases, these lesions were thought to be occasionally associated with mild to moderate forelimb lameness, typically responsive to conservative therapy. RUIN and RULD are underrecognized orthopedic entities with differing breed predispositions. The proposed entities aim to support clinicians in improving future identification of those entities and guiding future research for pathogenesis and case management.