Paint horse, gelding, 3 years and 6 months of age. Presented with a superficial wound in the area of the right stifle. At the clinical examination, a lameness on the hind right limb, moderate at walk and severe at trot was diagnosed. The clinician localised the lameness on the stifle joint. Radiographic examination of the right stifle were performed. Two orthogonal view of the right stifle were taken: Caudocranial (leL) and lateromedial (right) Radiographic changes
- There is a moderate to severe periarticular soL tissue swelling, with complete loss of definition of the infrapatellar fat pad.
- There is an app. 1.5 cm in DM half-‐moon shaped separated mineral opacity from the caudal tibial plateau, mildly displaced.
- There is an additional, smaller (ca 7mm in size), almost triangular separated mineral opacity on the medial margin of the intercondylar fossa from the lateral trochlear ridge.
Radiographic diagnosis Acute avulsion fractures in the area of the aTachmentes of the cruciate ligaments (proximal aTachment of the cranial cruciate and distal of the caudal) on the right stifle with moderate periarticular soL tissue swelling. The close up and the arrow show the separate bone fragment from the lateral intercondylar fossa Comment
- The cranial cruciate ligament originates from the lateral wall of the intercondylar fossa and inserts with the cranial ligaments of the menisci lateral to the medial intercondylar eminence.
- The caudal cruciate ligament originates from the medial surface of the intercondylar fossa of the femur and inserts on the popliteal notch of the tibia.
- Sprain of the cruciate ligament with or without partial detatchment of the distal insertion of the cranial cruciate ligament occurs more frequently. In chronic cases, there may be bony proliferative changes in the area of the insertion (not visible in this case, which was considered an acute injury).
- The lateral joint space appears narrower compared to the medial side. Anyway, the judgement of the articular space in the stifle joint may be unreliable and influenced by the position of the limb.
- On the US examination, the lateral meniscus had a heterogeneus echogenicity and irregular delineation suggestive of meniscal lesions.
- Differential diagnosis for the periarticular soL tissue swelling are: increased filling of the stifle joint considering the history very likely hemarthrosis or synovitis (reactive versus septic) or swelling of the periarticular soL tissues (like edema, hemorrhage, cellulitis).
- Considering the poor prognosis, the horse was euthanized.
