Cranial cruciate ligaments in dogs: why do they rupture and how

The cranial cruciate ligament (CrCL) runs from the caudomedial part of the lateral condyle of the femur diagonally across the intercondylar fossa to the cranial intercondyloid area of the tibia. The caudal cruciate ligament (CaCL) runs from the lateral surface of the medial femoral condyle caudodistally to the lateral edge of the popliteal notch of the tibia. The cruciate ligaments consist of two anatomically and functionally different parts. The CrCL has a stronger caudolateral and somewhat smaller craniomedial part. In extension of the stifle joint, both parts are taut. In flexion, the caudolateral band is loose whereas the craniomedial band is taut. The cruciate ligaments receive their blood supply from vessels of the synovial tissue ensheating them.