Ankle Joint Tuberculosis

With little surrounding soft tissue, ankle abscesses easily rupture through skin forming sinuses with chronic mixed infection, mostly anterior/lateral. Late signs include foot drop and varus deformity. Since the ankle communicates with the subtalar joint, subtalar TB often coexists. Ankle TB is 3.4% of bone TB, lowest among the three major lower limb joints. Synovial TB is more common and more likely to progress to total joint TB than osseous TB, especially talar and distal tibial TB.

Common Symptoms

Sprain; osteoporosis; bony destruction; pain and swelling below medial malleolus

Causes and Pathogenesis

(1) Etiology: Mycobacterium tuberculosis does not directly invade joints, so nearly all osteoarticular TB is secondary. (2) Pathogenesis: 1. Osseous TB: Cancellous bone TB is central (infiltration/necrosis, sequestra, cavities) or marginal (small defects). Compact bone TB starts in the medullary cavity, with pus elevating periosteum and producing onion-skin new bone. Metaphyseal long-bone TB has features of both. 2. Synovial TB: Infected synovium swells, congests, and thickens. 3. Total joint TB: Starts as simple osseous or synovial TB; granulation undermines articular cartilage margins, detaching it from bone. Early total joint TB has limited cartilage destruction that may recover with exercise; late total joint TB destroys most cartilage leading to fibrous or bony ankylosis.

Treatment

Surgical treatment, drug therapy, supportive therapy, rehabilitation

Preventive Measures

1. Control the source: Early chemotherapy for sputum-positive TB rapidly reduces and eliminates bacilli (~100% cure); early detection and treatment is the core of modern TB control. 2. Cut transmission: TB is mainly airborne.

Department to Visit

It is recommended to visit the Orthopedic Surgery department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.