Computed tomographic anatomy of the equine stifle joint

Objective-To provide a detailed computed tomography (CT) reference of the anatomically normal equine stifle joint. Sample-16 hind limbs from 8 equine cadavers; no horses had evidence of orthopedic disease of the stifle joints. Procedures-CT of the stifle joint was performed on 8 hind limbs. In all limbs, CT was also performed after intra-articular injection of 60 mL of contrast material (150 mg of iodine/mL) in the lateral and medial compartments of the femorotibial joint and 80 mL of contrast material in the femoropatellar joint (CT arthrography). Reformatted CT images in the transverse, parasagittal, and dorsal plane were matched with corresponding anatomic slices of the 8 remaining limbs. Results-The femur, tibia, and patella were clearly visible. The patellar ligaments, common origin of the tendinous portions of the long digital extensor muscle and peroneus tertius muscle, collateral ligaments, tendinous portion of the popliteus muscle, and cranial and caudal cruciate ligaments could also be consistently evaluated. The cruciate ligaments and the meniscotibial ligaments could be completely assessed in the arthrogram sequences. Margins of the meniscofemoral ligament and the lateral and medial femoropatellar ligaments were difficult to visualize on the precontrast and postcontrast images. Conclusions and Clinical Relevance-CT and CT arthrography were used to accurately identify and characterize osseous and soft tissue structures of the equine stifle joint. This technique may be of value when results from other diagnostic imaging techniques are inconclusive. The images provided will serve as a CT reference for the equine stifle joint. (Am J Vet Res 2011;72:512-)