Fractures of the ankle are serious because they involve an important weight-bearing joint. They are intensely painful, heal slowly, and present a significant risk for later complications, such as traumatic arthritis and chronic pain.
Ankle bones can fracture in various ways. A stress fracture is a crack in the outer shell of the bone, necessitating limited weight bearing and possibly a cast. Continued activity can cause even a small stress fracture to worsen until a complete, larger fracture occurs.
A simple fracture is more serious than a stress fracture and involves a complete break of the bone into two pieces. In a comminuted fracture, the bone is shattered into several fragments.
Fractures may be displaced, in which the broken bones are moved out of their normal position, or nondisplaced, in which the bones are minimally misaligned. Fractures also may be open, in which a portion of the broken bone protrudes through the skin, or closed, involving no skin breakage.
The goal of the attending physician is to restore the damaged ankle joint to as close to its original position as possible. This is important because any displacement of the bones can cause problems in the future.
The most common complication is traumatic arthritis, which occurs as a result of damage to the cartilage. Normally, the cartilage in the ankle allows the bones to articulate without friction. When cartilage breaks down and wears away, the bones grind against each other. Pieces of cartilage may break away and migrate into the ankle joint. This causes painful inflammation and fluid buildup in the joint lining (synovial tissue), resulting in swelling and stiffness.
As more layers of cartilage wear away from the ankle joint, the space within the joint becomes narrower. This produces imbalances in other joints in the body and can lead to problems in the knees, hips, back, and neck. It also brings the exposed, cartilage-depleted ends of the anklebones into painful, grinding contact. Over time, leg and foot deformities can develop, causing severe, disabling pain.
In many cases, an ankle fracture must be set. To set a broken ankle, the physician requests a series of x-rays to determine the nature and position of the fracture and what corrective actions to take. Uncomplicated simple fractures may require little more than carefully refitting the broken bone's ends together. If the wound is displaced, or open, antibiotics are prescribed to prevent infection.
After the ankle is immobilized with a rigid cast, the patient is given a pair of crutches to keep weight off the injured foot. The broken bone gradually heals, and in most cases, the patient can begin light walking and rehabilitative therapy in 8 to 12 weeks.
Simple fractures may require surgery to reset the bone. Surgery can be extensive if the fracture is comminuted. Repositioning the shattered fragments can be like fitting together pieces of a jigsaw puzzle. Screws, metal plates, pins, or staples may be used to stabilize the pieces in position so healing can progress. The object is to restore the joint as closely as possible to its original configuration.
Patients who develop arthritis as a result of an ankle injury generally receive anti-inflammatory drugs to relieve swelling and pain. However, the degenerative nature of the condition sometimes results in the need for surgery.
Surgery may involve trimming away damaged synovial tissue, smoothing out rough-worn cartilage, and removing fragments of cartilage or bone from the joint. Whenever possible, the procedure is performed arthroscopically, using a narrow, flexible, fiber-optic viewing tube called an arthroscope that enables the surgeon to see inside ankle and work with precision.
In severe arthritic conditions resulting from multiple fractures, bone fusion may be performed. Affected joints are fastened together with surgical screws or rods so they eventually grow together and become one larger bone. This procedure eliminates the joint and the motion that causes the pain. However, the patient is left with a noticeably stiff-legged gait. Trading limited mobility for pain reduction is usually a last resort.