Ankylosis is a condition of, or term used, for the sign/symptom of abnormal stiffness, immobility, or abnormal bending of a joint.

Ankylosis may be caused by diseases of the bone or joint (e.g., arthritis); trauma (e.g., fractures); surgery; or from contractures due to prolonged immobility. Ankle ankylosis may also be a congenital condition, or it may be hereditary.

Manifestations may include: restricted range of motion, immobilization, and stiffness. (Normal ROM for ankle plantar flexion is approximately 0 to 45°, and for ankle dorsiflexion 0 to 20°). Other signs and symptoms may include: pain or tenderness; swelling; deformity; or crepitus that may arise from joint disease such as arthritis.

Laboratory tests will be based on the underlying disease or condition. Physical examination; range of motion tests (plantar flexion and dorsiflexion); as well as tests of the ligaments at the ankle and foot may be performed. X-rays, computed tomography (CT) scan, and magnetic resonance imaging (MRI) are used for diagnosis. A goniometer is used to measure range of motion.

General treatment for ankylosis may include physical therapy, and maintenance of the joint in a functional position with range of motion exercises to affected joints (e.g., daily mobilization of the joint). If the ankylosis was surgically created, the joint is kept immobilized in correct body alignment for 6 to 12 weeks until the bone is healed. Medications and other therapies such as traction may be instituted to treat other conditions. Arthroscopy may relieve pain and increase mobility.

Deterioration at the site of the joint may occur due to decreased activity. The possibility of long-term physical therapy exists.

• The rating schedule for musculoskeletal was updated on February 7, 2021. Protection still does apply and should be considered with existing evaluations (38 CFR 3.951(a)).

• None.