The femur, tibia, fibula and patella comprise the knee bones. According to the University of Texas Medical Branch website, the knee provides flexible mobility during which it bears considerable weight. A number of injuries may occur to the knee, both from trauma and aging. Some conditions of the knee may present at birth. Some of these congenital defects and traumas may cause deformities of the bones of the knee.
Amyoplasia
Amyoplasia, a rare birth defect, presents with multiple joint contractures in the upper and lower extremities, including the knee joint. According to the website of the American Academy of Orthopaedic Surgeons, this deformity, while not progressive, may get worse as the sufferer ages. The affect on the muscles and skeleton is severe. No known cause of amyoplasia exists. Treatment for this birth defect occurring in the knee usually begins directly after birth and includes splinting of the joint and physical therapy. Surgical correction also factors in eventually.
Ehlers-Danlos syndrome
Ehlers-Danlos syndrome, a deformity of the connective tissue that provides support to the skin, muscles and ligaments, causes unstable joints, including the bones of the knee joint. According to the Arthritis Foundation, this disease causes hypermobility of the joints, or loose joints, that may result in easily dislocated knees and sprained knees. Treatment options for Ehlers-Danlos syndrome include exercise to improve joint stability, avoiding activities that can injure the joints and surgery to repair fractures and dislocations.
Arthritis
Arthritis creates a deformity in the knee bones by allowing unprotected bone ends to rub together. According to the American Academy of Orthopaedic Surgeons website, arthritis gradually wears away or destroys cartilage in the knee joint. Symptoms may include swelling, pain and weakness in the knee, as well as decreased mobility. Physicians may suggest lifestyle modification, exercise, supportive devices, drug therapy and surgery to treat pain and inflammation or correct damage to the knee joint.
