Impingement of the Ankle
Ankle impingement is a condition whereby the patient suffers from a restriction in their ankle movement due either to a bony or soft tissue problem. The typical causes of this condition are usually irritation of the capsule or synovial membrane of the ankle secondary to a single or a repeated series of accidents or incidents. Ankle sprains, especially if repetitive, can lead to chronic pain and impingement syndromes. This gives the patient continual pain on weightbearing and limits their mobility and sporting activities. Estimates vary but 10% of people suffering ankle sprains may develop some degree of impingement.
Acute ankle impingent is most commonly caused by the foot being moved into a pointed down and turned in position with the body weight on it, often from stepping on an uneven object or dip in the surface. Impingent can be at the front (anterior) or the back (posterior) or relate to the connecting joint between the tibia and the fibula just above the ankle joint. In anterior impingement the patient feels like the movement of the foot upward is blocked by the front of the ankle. Dorsiflexion of the ankle, especially if forced such as by lunging forward on the affected foot, is part of the diagnosis of this type of problem.
If the intervening joint between the tibia and fibula is involved then there will be tenderness and pain on palpating that area firmly and on pressing the two sides of the ankle together. Posterior impingement may be harder to diagnose, the symptoms being less clear although a forceful downward movement of the foot may cause pain. Anterior impingement can be brought on by kicking a ball in soccer and doing repetitive lunging manoeuvres such as in fencing or ballet. Repeated micro damage to the area leads to chronic injury and the formation of bony spurs at the front edge of the joint.
Investigations for ankle impingement often do not contribute much to the diagnostic process. Plain x-rays, bone scans and CT scans are typically normal, although patients who have anterior impingement may have bony spurs on the front edge of the tibia and on the talus, the ankle bone. Magnetic resonance imaging or MRI scanning is more useful as it enables the doctor to identify abnormalities in both bony and soft tissue structures.
The initial management of this syndrome is always conservative with activity modification a significant goal as reducing the stresses suffered by the ankle will be likely to relieve the symptoms to some degree. Patients may be prescribed non-steroidal anti-inflammatory drugs to help the pain and attend for physiotherapy. Physiotherapists can perform mobilising techniques on the ankle and foot joints, give ultrasound, perform deep tissue massage and work on joint ranges and muscle strengthening. They also provide ankle braces for lateral support or to limit joint movement and assess and provide in shoe foot orthotics to correct abnormal foot mechanics.
Conservative treatment methods may not settle impingement pain and then consideration turns towards surgical intervention. Modern operation is usually performed arthroscopically, any loose tissue cut away, and bony spurs or soft tissue abnormalities removed. Patients can rapidly mobilise after surgery and almost normal walking can start a few hours after operation provided minor work has been performed. Patients may need to wait 4 to 6 weeks before fully resuming their normal routines, in some cases guided by physiotherapists. Results from trials of surgery for this condition have shown that eighty percent have good to excellent outcomes.
In more serious cases patients may wear an ankle brace and use crutches to reduce the weight borne on the ankle, working up to full weight bearing over a week or two. Physiotherapy may then commence once the brace has been removed, starting with range of motion exercises to the ankle and foot joints. Physiotherapists also use ice and other treatments such as ultrasound to reduce pain and inflammation. Once the ankle has begun to settle the physio will progress the patient onto gym exercises without significant weight such as using a static bike, and then to weight bearing exercises involving power, coordination, joint position sense and balance.