Unusual presentations of osteoarticular tuberculosis: experience from a tertiary center in Liguria

Abstract Background Osteoarticular tuberculosis (TB) is a rare but serious manifestation of extrapulmonary TB. Despite improvements in imaging and microbiological diagnostics, bone TB remains challenging to identify because its clinical presentation is often nonspecific. While the spine and knee are the most frequently affected sites, involvement of less typical skeletal locations can occur, further complicating timely diagnosis. Methods We retrospectively reviewed all cases of bone TB diagnosed at the ‘Malattie Infettive e Ortopedia Settica’ Department—ATS Liguria, Savona area, from 2022 to 2025. Diagnostic confirmation relied on imaging, histopathology, culture, and polymerase chain reaction (PCR) testing for Mycobacterium tuberculosis. Results Eight patients (6 males, 2 females; mean age 50 years) were identified. Three were Italian, and five were foreign-born. Two patients had vertebral TB: an 80-year-old Ukrainian woman and a 25-year-old Gambian man. Both developed paraparesis requiring surgical stabilization; intraoperative cultures confirmed the diagnosis. Two patients (aged 19 and 23) presented with chronic knee arthritis. Initial arthrocentesis cultures and PCR were negative. Diagnosis was achieved through surgical biopsy; in one case, culture remained negative, but histopathology revealed necrotizing granulomas with Langhans giant cells, and PCR on the histological piece identified M. tuberculosis. A 75-year-old Italian woman with diabetes developed a tuberculous prosthetic joint infection, confirmed by synovial fluid culture. An 86-year-old Italian man with squamous cell carcinoma had mandibular TB diagnosed by bone biopsy, along with concurrent pulmonary TB. A 74-year-old Italian man presented with wrist pain and a draining fistula; bone culture was positive for M. tuberculosis. A 14-year-old boy had ankle inflammation and cervical lymphadenopathy; bone biopsy confirmed TB. All patients tested positive on the QuantiFERON-TB Gold assay. Only one had pulmonary involvement, and one had lymph node disease. All isolates were susceptible to first-line drugs. Treatment typically lasted 12 months, although one patient discontinued therapy after eight months due to hepatotoxicity. Conclusions Bone TB should be considered in cases of chronic osteoarticular infection, even in non-endemic settings and when atypical anatomical sites are involved. Diagnostic accuracy improves when culture, histopathology, and molecular testing are combined. Early recognition and multidisciplinary management are essential to optimize outcomes.