Hip Joint Tuberculosis

Hip TB accounts for ~7.20% of systemic osteoarticular TB, second only to spinal TB. It is most common in children and young adults, more in males; 7-10% also have sacroiliac or lower lumbar TB, especially preschool children. Onset is insidious; the earliest symptom is altered gait (heavy weight on the sound limb, light on the affected) with slight limp. Patients then complain of thigh pain radiating to the knee and medial anterior thigh. Limp and pain are initially intermittent and relieved by rest, then become persistent.

Common Symptoms

Fatigue; weakness; flattened drooping gluteal fold; child refusing to lie supine; anorexia; persistent pain; low fever; weight loss; nutritional disturbance

Causes and Pathogenesis

Caused by tubercle bacilli, with pathological patterns: (1) Simple synovial TB: congestion, edema, exudation, fibrous hyperplasia confined to synovium. (2) Simple osseous TB: confined to bone, in the femoral head epiphysis or proximal metaphyseal margin. (3) Total joint TB: destruction of articular cartilage; early if only partial cartilage necrosis, late if full-thickness necrosis with severe bony destruction and dislocation. Trauma does not cause local TB, but chronic strain contributes. (1) Transmission: 80-90% of TB sputum (especially cavitary) is laden with bacilli; do not spit. Coughing/sneezing contaminates air. Gastrointestinal infection is rare; pasteurization (65-72°C) prevents it. Bacilli cannot cross intact skin; direct osteoarticular infection and congenital TB are extremely rare. (2) Formation of foci: Primary tuberculous foci form in childhood; inhaled/ingested bacilli multiply under favorable conditions causing exudative inflammation; some enter lymphatics then blood, forming emboli distributed systemically; most are killed, a few multiply into tiny foci that are mostly walled off by fibrous tissue. With age, declining immunity, or other stress, latent foci reactivate months to decades later, forming symptomatic lesions. Hip TB starts from a juxta-articular osseous focus in cancellous bone or periosteum; primary osseous TB accounts for >90% of hip TB. Pathogenesis: Simple synovial and osseous TB are uncommon; most patients present with total joint TB. The acetabulum is most often affected, then femoral neck, then head. Simple synovial TB rarely forms abscesses; osseous TB more often does. Acetabular pus penetrates cartilage into the hip, tracks posteriorly to the buttock or medially into the pelvis. Femoral neck pus tracks along the medullary canal to the greater trochanter or lateral thigh. Femoral head pus early penetrates cartilage; late abscesses appear anteromedially where the capsule is thin and communicates with the iliopsoas bursa, draining as sinuses (~20% at presentation); chronic mixed infection causes sclerosing osteomyelitis. In late disease, the ligamentum teres is destroyed; severe acetabular/femoral head destruction causes posterior dislocation; muscle spasm produces flexion-adduction deformity. Severe static destruction leads to fibrous or bony ankylosis in flexion, adduction, and external rotation; occasionally a pseudarthrosis forms. Pediatric hip TB affects growth: synovial/acetabular healing may accelerate growth causing femoral head enlargement, neck lengthening, coxa valga, and limb lengthening 0.5-2.5 cm; femoral head/neck lesions near the physis may inhibit growth causing coxa vara and shortening 1-3 cm; late total joint destruction can shorten the limb by >10 cm.

Treatment

Surgical treatment, drug therapy, supportive therapy, rehabilitation

Preventive Measures

1. Disinfect and isolate open TB patients to reduce pulmonary/intestinal and thus osteoarticular TB. 2. Improve medical techniques for early diagnosis and treatment. 3. Promote public health campaigns on not spitting, disinfection, health exams, early treatment, and BCG. 4. Since hip TB is secondary to primary sources like pulmonary TB, preventing and thoroughly treating active foci is key.

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.