(Kiosk 2) Atypical Septic Hip Arthritis: A Case Report

Case Diagnosis: Southeast Asian male in mid 50s with tuberculosis septic arthritis of the hip.

Case Description or Program Description: Non-verbal patient was admitted to hospital for two-month history of right thigh pain and fever (102˚F). MRI demonstrated extensive increased T2 signal at the right hip joint consistent with septic joint or osteomyelitis. On day 3, the patient underwent a total hip arthroplasty and antibiotic spacer insertion. The procedure note reported, "the joint was full of thick fluid with a ricotta cheese-type appearance. Remaining bone stock was solid." Patient presented to acute inpatient rehab on postoperative day 5. The cultures remained negative, and a 6-week course of empiric IV antibiotics were started due to suspected bacterial osteomyelitis. The patient made strong progress meeting rehabilitation goals. The patient was planned for discharge on postoperative day 14 when the laboratory reported a positive culture for mycobacterium tuberculosis (TB).

Setting: Acute Inpatient Rehabilitation Hospital

Assessment/Results: Patient was treated with antitubercular antibiotics and assessed for active pulmonary TB. Chest X-ray and CT showed chronic appearing left upper lobe complex and sputum sample was negative. Per the health department, patient was cleared for discharge. He was discharged home in good and stable condition.

Discussion (relevance): Tuberculosis septic arthritis of the hip often presents insidiously as subacute to chronic joint pain and swelling. The diagnosis is frequently delayed due to decreased awareness and lack of constitutional or pulmonary involvement. Here key presentation findings to raise clinical suspicion included chronic thigh/hip joint pain, caseous necrosis description in the operation report, travel/ birth history, and prolonged negative cultures.

Conclusions: Septic arthritis of the hip represents a relatively rare form of extrapulmonary TB. Awareness is key to overcoming the often delayed diagnosis. Interprofessional collaboration among medicine, surgery, and rehabilitation are important to maintain good joint function.