Enthesopathy and desmitis of the medial collateral ligament of the cubital joint in 4 horses

Case Description—4 horses with enthesopathy and desmitis of the medial collateral ligament of the cubital joint were examined. Clinical Findings—All 4 horses had a history of acute, severe, unilateral forelimb lameness and had signs of pain during manipulation of the affected upper forelimb; 2 also had swelling in the axillary region. There was no improvement in lameness after diagnostic local analgesia below the carpal region, and 1 of 4 horses had mild improvement after cubital joint analgesia. Radiography revealed enthesophyte formation on the radial tuberosity and linear mineralization of the medial collateral ligament in 2 horses and periosteal reaction on the humeral condyle in all 4 horses. One horse had mild osteoarthritis of the cubital joint, and 3 had osteophytosis of the cranial aspect of the radius. Although all horses were initially examined because of an acute onset of lameness, all had chronic abnormalities visible on imaging. Ultrasonography revealed an irregular boney contour and enthesopathy at the insertion of the short medial collateral ligament to the radial tuberosity and desmitis of the short medial collateral ligament. Two horses had radiographic evidence of similar but less severe lesions of the contralateral cubital joint. Treatment and Outcome—All horses received phenylbutazone and rest. All horses were free of lameness after a median of 3 months (range, 2 to 4 months) and returned to previous use after a median of 6 months (range, 3 to 8 months). Conclusions and Clinical Relevance—The results of the present report suggested that performance horses with enthesopathy and desmitis of the medial collateral ligament of the cubital joint may have a good prognosis for return to previous use following appropriate treatment.