The stifle joint is one of the largest, complex hinge joints in the equine skeletal system. The role of the stifle joint ranges from locomotion, through to a fundamental role in the reciprocal apparatus in the pelvic limb.

Compared anatomically to the knee joint in human anatomy, the stifle has a locking mechanism that enables the pelvic limb to stay ridged and allow the horse to stand resting for long periods while exerting minimal energy.

First, a brief anatomical review is necessary by the farrier following the vet’s exam and diagnosis.

Anatomical Review

The stifle is considered a complex joint due to the number of bones, numerous ligaments and muscular network that surround the structure. The tibia and femur create the large hinge joint of the stifle. While the patella is not regarded as part of the femorotibial joint, the patella is responsible for the unique stay apparatus of the pelvic limb. In a 2002 paper written by Sue J. Dyson, VetMB, PhD1, she states, “Ac­curate knowledge of functional ana­tomy is crucial for understanding the role of the stifle in the reciprocal apparatus of the hind limb.”

The femur. The femur is the upper long bone of the pelvic limb and is the largest long bone in the horse’s body. Proximally, the femur forms a ball-and-socket joint with the pelvis to form the hip joint. Distally, the femur meets the tibia and patella at the stifle joint. It also serves as an attachment point for the deep and middle gluteal…