Tuberculous osteomyelitis of the midfoot in the absence of a pulmonary lesion: a case report

Isolated C-C joint tuberculosis - A diagnostic dilemma

Painful lytic lesions of the foot raise a diagnostic dilemma for the foot surgeon. The localization of the lytic lesion in the mid foot is rare and isolated involvement of the calcaneo-cuboid (C-C) joint is even rarer. Early diagnosis is imperative in the mid foot to avoid rapid disease spread due to multiple venous interconnections. The diagnostic possibilities include infection, tumor (primary and metastasis), inflammatory arthritis, foreign body prick among others. The clues to rule out other differential diagnoses of lytic lesions can be history and examination, both clinical and radiographic but the gold standard for final diagnosis remains biopsy and histo-pathological examination. We describe two cases of lytic lesion around the calcaneo-cuboid joint and discuss the diagnostic dilemma. The lesions were diagnosed as tubercular in nature after histo-pathological examination of open biopsy. Both cases had complete resolution of lytic lesions and had fair functional outcome after completing the course of anti-tubercular therapy. Tuberculosis (TB) is making a worldwide resurgence due to the epidemic of HIV. In order to control this global epidemic of TB, it is important to know about all the possible presentations of the disease, including rare ones. Tuberculosis if diagnosed early in the disease course, when the pathology is localized, can result in good to fair results in the foot if adequately managed by anti-tubercular therapy.

LEVEL OF EVIDENCE

V.

Isolated tuberculous osteomyelitis of the talonavicular joint without pulmonary involvement-a rare case report

Tuberculosis is one of the leading causes of death worldwide amongst curable diseases. It is estimated that one-third of the world's population has been diagnosed with tuberculosis infection [1]. The prevalence is on the rise with an estimated 9.4 million new cases per year worldwide [1]. Tuberculosis most commonly presents with pulmonary involvement. However, approximately 23-30% of patients found to be infected with tuberculosis have extrapulmonary symptoms [2]. Of those, only 1-3% have been found to have osseous disease. Skeletal involvement with a primary focus of tuberculosis usually affects major weight-bearing joints such as the hip and knee. Tuberculosis infections of the foot and ankle are very rare, accounting for 1% of all tuberculosis infections [2-4]. Difficulties arise in the timing of diagnosis, patient compliance of therapy and awareness of the less obvious presenting symptoms. Musculoskeletal tuberculosis, although rare, can be a problem. Its uncommon site, non-specific presenting symptoms and its ability to mimic numerous disorders make it more difficult to formulate a definitive diagnosis and, in turn, leads to therapeutic delays [5-7]. It is for this reason that we report this case in an effort to promote awareness.

Tuberculosis infection of the talonavicular joint

Isolated tuberculosis osteomyelitis affecting the foot is extremely rare. Symptoms are nonspecific and haematological investigations are often unhelpful making diagnosis difficult. We report the case of a 41-year-old female who presented with a 7-month history of a painful hindfoot following a minor ankle sprain. Inflammatory markers were mildly raised and initial radiographs showed only some mild narrowing of the talonavicular joint. MRI scanning suggested osteomyelitis centred over the talonavicular joint. Open biopsy confirmed areas of caseous necrosis but no acid-fast bacilli were seen. The final diagnosis was confirmed with culture of mycobacterium tuberculosis. A good recovery was seen following debridement and commencement of anti-tuberculosis chemotherapy. Unless an awareness of this condition exists, the diagnosis and therefore the appropriate treatment can often be delayed which may lead to significant consequences for the patient.