Partial avulsion of the ulnaris lateralis and enthesiopathy of the lateral epicondyle of the humerus in a thoroughbred race horse

Abstract

BackgroundThere is relatively little literature on elbow disease in the horse. The only published reports on soft tissue conditions describe collateral ligament and biceps brachii injuries.Case presentationA three-year old Thoroughbred gelding presented with a history of acute onset right forelimb lameness of less than one week duration, one month after commencing training in a National Hunt racing yard. Physical examination and peri-neural anaesthesia failed to localise the lesion. Lameness was localised to the distal humerus by nuclear scintigraphy and intra-articular anaesthesia. A partial avulsion of the tendinous origin of the ulnaris lateralis and enthesiopathy of the lateral humeral epicondyle was diagnosed on ultrasonography. Ultrasonographic findings were loss of longitudinal fibre pattern, a discrete hypo-echoic region within the ulnaris lateralis tendon of origin, and remodelling of the lateral epicondyle of the right humerus at the site of the origin of the ulnaris lateralis. No abnormalities were identified on radiography. The lameness did not resolve with rest, but was successfully treated with extra corporal shockwave therapy (ECSWT) and intra-lesional corticosteroid injections.ConclusionThis is the first report of partial avulsion of the ulnaris lateralis and enthesiopathy of the lateral humeral epicondyle in the horse. In contrast to other reported soft tissue conditions of the elbow, this horse had a successful return to work. This case highlights the value of ultrasonography in assessing peri-articular soft tissues, and the importance of pain relief as treatment in some soft tissue injuries.

CT is a feasible imaging technique for detecting lesions in horses with elbow lameness: A study of 139 elbows in 99 horses

“…A variety of conditions of the elbow joint has been described, most commonly osseous cyst‐like lesions in the proximomedial aspect of the radius 1–6 . Other conditions such as fractures, wounds, degenerative joint disease, 4 biceps brachii enthesopathy, 4,7 collateral ligament enthesopathy, 4,8,9 luxation, 10 septic arthritis and osteomyelitis, 11 avulsion of the ulnaris lateralis muscle, 12 and osteochondrosis 13,14 have also been reported. Osseous cyst‐like lesions are more commonly seen in younger horses, whereas degenerative joint disease is more common in older horses 4 .…”