The large femur bone connects the hip and stifle joints. Large muscle groups attach to the femur to allow flexion and extension of the rear limb. Abnormalities associated with the femur commonly occur from trauma. Trauma to the femur most commonly results in a fracture; dislocation of the femur from the hip joint occurs infrequently. Horses with femur fractures are visibly lame and cannot bear weight on the limb. Diagnosis of a femur fracture is based on x-ray findings. Fractures in foals may be able to be corrected surgically. Unfortunately, femur fractures in adults carry a poor prognosis for return to function and euthanasia is often recommended.