Abscess formation is an early and prominent feature, whether the disease is of osseous or synovial origin, and sinuses are liable to form around the joint. Outlying abscesses and sinuses are usually the result of infection of the tendon sheaths in the neighbourhood.
Diagnosis.—When teno-synovitis occurs independently of disease of the ankle, the swelling is confined to one aspect of the joint. In sarcoma of the lower end of the tibia, the swelling lacks the uniform distribution of that met with in joint disease. In Brodie's abscess of the lower end of the tibia there may be swelling of the ankle, but there is an area of special tenderness on percussion over the bone.
Treatment.—The foot is immobilised at a right angle to the leg by splints or plaster of Paris; if articular symptoms are absent or have subsided, a Thomas' knee splint should be applied to enable the patient to move about without bearing his weight on the affected foot ([Fig. 125]). To inject iodoform, the point of the needle is inserted below either malleolus, and is then pushed upwards alongside of the talus. If localised disease in one of the bones is recognised before the joint is infected, it should be eradicated by operation.
When the disease is diffuse and resists conservative treatment, excision should be performed, the articular surfaces of the constituent bones being removed, and if necessary the whole of the talus.
Amputation is only called for in adults with rapidly progressing disease and diffuse suppuration, and in cases which have relapsed after excision.
The other diseases of the ankle include pyogenic, gonorrhœal, rheumatic, gouty, and hysterical affections, arthritis deformans, and Charcot's disease. The last-named is generally associated with a rapid and painless disintegration of the bones of the ankle and tarsus, resulting in great deformity and loss of the arch of the foot—sometimes associated with perforating ulcer of the sole.
Tuberculous disease in the tarsus, metatarsus, and phalanges has been considered in the chapter on Diseases of Bone.