Diagnóstico Ultrassonográfico de Ruptura do Tendão Gastrocnêmio em Cão

Background: The gastrocnemius tendon, one of the components of the common calcaneal tendon (CCT), is integral in tarsal extension and knee flexion movement. CCT ruptures are uncommon, and ultrasound findings unique to the gastrocnemius component have been scarcely documented. This report aims to describe the ultrasonographic findings of a gastrocnemius tendon rupture in a dog— a topic not extensively covered in the literature, emphasizing the importance of ultrasound in diagnosing such ruptures. Case: A four-year-old female greyhound weighing 20 kg was brought to a university veterinary hospital for a clinical evaluation due to acute lameness in the left hind limb. During the orthopedic examination, a suspected CCT rupture prompted an ultrasound examination. The left hind limb showed intact common and superficial digital flexor tendons, a heterogenous and substantially hypoechoic appearance of the gastrocnemius tendon, and an adjacent hematoma. These findings were consistent with a partial CCT rupture involving the gastrocnemius component. The suspicion was confirmed through gastrocnemius tenorrhaphy and temporary tarsal arthrodesis. The patient demonstrated limb function recovery post-surgery. Discussion: Partial ruptures of CCT only involving the gastrocnemius component have been poorly described in the veterinary literature. While radiography is the preferred method of examination to diagnose suspected orthopedic conditions, ultrasound is widely available in small animal care and highly accurate in detecting such tendon injuries. This report elucidates the ultrasonographic characteristics of a complete gastrocnemius tendon rupture, underscoring the important role of ultrasound in the diagnosis as it effectively differentiates between complete and partial tendon ruptures and acute and chronic tendinopathies. More importantly, its sensitivity in determining the lesion location and extent proves invaluable when clinical and orthopedic examinations are inconclusive. Hence, its utility as an auxiliary tool for evaluating tendon injuries is emphasized.