SAEVA Proceedings 2016 | Page 63

  DIAGNOSIS AND TREATMENT OF STIFLE LAMENESS IN THE SPORT HORSE Michael Schramme VetAgro Sup, Campus Vétérinaire de Lyon, Marcy L’Etoile, Rhône-Alpes, France Introduction The stifle is not an unusual site of lameness in the Sporthorse. While it is a common site of developmental conditions such as osteochondritis dissecans and subchondral cyst-like lesions in the young animal, soft tissue injuries are a common cause of lameness arising from the stifle in adult Sportshorses. Clinical examination of stifle lameness Traumatic injuries to the stifle are commonly seen in association with external trauma from a kick or a collision with a fixed or moving heavy object. Typically this occurs in event horses that hit cross-country fences with the stifle region of one or both hindlimbs. However, stifle injuries have also been observed in horses turned out at pasture without any history of trauma. In comparison with other diarthrodial joints, the stifle is characterised by the poor congruity between the spherical femoral condyles and the flat plateau at the proximal end of the tibia, and by an intricate support system of extra- and intra-articular ligaments and two fibrocartilagenous discs (menisci). These structures are at risk of injury when the loaded stifle is subject to craniocaudal, lateromedial or twisting forces outside of the normal physiological range. Careful clinical examination by inspection and palpation of an injured stifle can be rewarding. The landmarks for palpation are the patella, the tibial crest, the patellar ligaments, the combined tendon of the peroneus tertius and the long digital extensor, the collateral ligaments, the proximal medial articular margin of the tibia, and the medial border of the medial meniscus immediately proximal to it. The presence of stifle effusion is always significant. Diffuse swelling over the cranial aspect of the stifle causes loss of the characteristic cranial silhouette of the stifle region and is commonly associated with periarticular bruising following acute trauma. Effusion of the femoropatellar joint is most prominent just distal to the distal border of the patella, proximally between the patellar ligaments. It causes a characteristic bulge in the cranial silhouette of the stifle just distal to the patella. Effusion of the medial femorotibial joint is best appreciated as a medial bulge of the joint capsule through a window bordered by the medial collateral ligament caudally, the proximal medial articular margin of the tibia with the medial border of the medial meniscus distally, the medial patellar ligament cranially and the medial femoral metaphysis proximally. Distension of this joint is a serious clinical sign, most commonly associated with traumatic arthritis of the medial femorotibial joint. Effusion of the lateral femorotibial joint is less easily identified because of the presence of the broad common tendon of the long digital extensor and the peroneus tertius in the extensor fossa overlying the craniolateral aspect of this joint. 15-­‐18  February  2016      East  London  Convention  Centre,  East  London,  South  Africa     62