Horse unable to walk on front leg - what is antebrachial compartment

Abstract

CASE DESCRIPTION: An 18-year-old Paint stallion (horse 1) and a 17-year-old Morgan gelding (horse 2) were evaluated because of an acute onset of severe unilateral forelimb lameness. CLINICAL FINDINGS: Both horses were unable to bear weight on the affected forelimb and had a dropped elbow appearance. Radial nerve paralysis, triceps myopathy, and fractures of the humerus and ulna were ruled out. The caudal aspect of the affected antebrachium of each horse was very firm to palpation and became firmer when weight was shifted onto the limb. Ultrasonographic examination revealed swelling and suspected intramuscular hemorrhage of the caudal antebrachial muscles. On the basis of clinical examination and diagnostic imaging findings, both horses had antebrachial compartment syndrome diagnosed. Lameness did not substantially improve with medical treatment in either horse. TREATMENT AND OUTCOME: Caudal antebrachial fasciotomy was performed in each horse. Following sedation and local anesthetic administration, a bistoury knife was inserted through small incisions to perform fasciotomy. Horses remained standing throughout the procedure and were immediately able to bear weight on the affected limb without signs of discomfort. Horse 1 developed colitis and horse 2 developed a mild incisional infection, but both fully recovered and returned to their previous activities. CLINICAL RELEVANCE: Antebrachial compartment syndrome is a rare cause of severe unilateral forelimb lameness and should be considered as a differential diagnosis in horses with a dropped elbow appearance. Both horses of this report had a successful outcome following antebrachial fasciotomy.