Tubercular involvement of the lateral malleolus and adjacent calcaneus: presentation of a rare case and review of the literature

Foot and ankle tuberculosis: A case report and review of the literature

Key clinical message

It is important to consider foot and ankle tuberculosis (TB) as a potential cause of cystic lesion around the ankle, especially in patients with a history of TB. Early diagnosis and treatment with a rifampin-based regimen for a duration of 12 months can lead to good functional and clinical outcomes.

Abstract

Skeletal TB is an uncommon accounting for 10% of extra-pulmonary TB may present slowly over an extended period of time, making a diagnosis difficult and time-consuming (Microbiology Spectr. 2017;5:5). For the best possible outcome and to reduce the risk of deformity diagnosis must be early (Foot (Edinb). 2018;37:105). For the treatment of drug-susceptible musculoskeletal illness, a rifampin-based regimen lasting 12 months is advised (Clin Infect Dis. 2016;63:e147; J Bone Joint Surg Br. 1993;75:240; Tubercle. 1986;67:243). A 33-year-old female who are working as nurse with diffuse, persistent and low in intensity ankle pain not aggravated relieved by analgesia and swelling over a period of 2 months, static not related to activity. With past medical history of partially treated pulmonary TB 1 year ago. She reported night sweats and low-grade fever during this period, and she denied any history of trauma. The right ankle was globally swollen and tender anteriorly and on the lateral malleolus. The skin over the ankle showed dark discoloration with cautery marks with no discharging sinuses. The range of motion of the right ankle was decreased. The plain x-ray of the right ankle showed three cystic lesion at the distal tibia, one cyst at the lateral malleolus and another one at the calcaneum. Surgical biopsy and expert gene test confirmed the diagnosis of tuberculous osteomyelitis. The patient was planned for surgical curettage of the lesion. After the confirmation of the diagnosis of TB with the biopsy and gene expert test, with consultation of senior chest physician the patient fitted to anti-tuberculous regimen. The patient had good functional and clinical outcome. This case report highlights the importance of considering skeletal TB as a potential cause of musculoskeletal symptoms, especially in patients with a history of TB. Early diagnosis and treatment with a rifampin-based regimen for a duration of 12 months can lead to good functional and clinical outcomes. Further research on the management and prevention of musculoskeletal TB is warranted to improve patient outcomes. The lesson behind this case is that the diagnosis TB osteomyelitis should be on the top of differential diagnosis of multiple cystic lesions around the foot and ankle especially in area where TB is endemic. Early diagnosis and early start of anti-tuberculous therapy can lead to full cure of the patient and in bad situation can minimize the complications.

Tuberculosis presenting as arthritis of the ankle: A case report

Tuberculosis presenting as monoarticular involvement in immunocompetent patients is rare. Here, we report a Sri Lankan patient presenting with ankle swelling due to tuberculosis with no other extrapulmonary or pulmonary involvement. Magnetic resonance imaging showed destruction of articular cartilage of the ankle joint with chronic inflammation of the subtalar joint. The diagnosis was confirmed by synovial tissue culture which was positive for Mycobacterium tuberculosis. The patient recovered uneventfully with anti-tuberculosis treatment. Therefore, a high degree of suspicion is necessary to diagnose extrapulmonary tuberculosis when patients are presenting with atypical monoarthritis.