Tuberculosis of the Skeleton: Pathophysiology and Disease Mechanism

Introduction

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis. While pulmonary TB is well known, extrapulmonary manifestations such as skeletal tuberculosis account for 1-3% of all TB cases. This form of TB primarily affects the spine, joints, and long bones.

Pathophysiology

The mechanism begins with hematogenous or lymphatic spread of Mycobacterium tuberculosis from a primary site, usually the lungs. The bacteria lodge in cancellous bone, triggering an inflammatory response.

Stages of Bone Tuberculosis

• Stage 1: Initial infection via hematogenous spread.
• Stage 2: Granuloma formation, causing localized bone destruction.
• Stage 3: Caseous necrosis and abscess formation.
• Stage 4: Progressive bone and joint destruction.

Clinical Manifestations

Symptoms of skeletal tuberculosis include chronic pain, swelling, restricted mobility, and constitutional symptoms such as fever and weight loss.

Diagnosis

Diagnosis involves imaging modalities such as X-ray and MRI along with microbiological tests such as PCR and culture studies.

Treatment

Management includes the standard anti-tuberculosis treatment (ATT) regimen with surgical intervention in severe cases.

Conclusion

Early detection and timely treatment of skeletal tuberculosis are crucial for preventing long-term disability.