Tuberculosis (TB) remains a significant global health challenge, despite advances in prevention and treatment. It is relatively rare in many parts of the world, yet continues to be a serious infectious disease, with its highest prevalence observed in developing countries. ^,, Among these, China—the most populous developing nation—bears a considerable burden, reporting >68 cases per 100,000 individuals.

Although TB most commonly affects the lungs, extrapulmonary disease is well documented and can involve almost any organ system. Approximately 3 % of extrapulmonary cases affect the peripheral joints, underscoring the disease’s potential musculoskeletal impact. Skeletal TB typically presents as monoarticular involvement in 80–90 % of cases, with nonspecific signs such as pain, swelling, and warmth. Because of its insidious onset and vague early manifestations, musculoskeletal TB often remains undiagnosed until more advanced stages.

While TB is most widespread in developing nations, it continues to be a relevant health concern in developed countries, including the United States. In 2018, the reported incidence of TB in the U.S. was 2.8 cases per 100,000, with an estimated 3 % presenting with musculoskeletal complications. If left untreated, articular TB may progress to severe consequences such as joint destruction, sinus tract formation, and even pathologic fractures, often resulting in long-term disability and impaired quality of life. ^, Early symptoms, including joint pain and swelling, tend to worsen over time, further emphasizing the importance of prompt recognition and treatment.

Radiological imaging plays an important role in evaluation, though findings are often nonspecific. Typical radiographic features of joint TB include soft tissue swelling, joint space narrowing, and periarticular osteopenia. MRI offers more detailed assessment, frequently demonstrating effusion, periarticular osteoporosis, bone lysis with periostitis, and thickening of the perisynovial membrane. However, MRI alone cannot confirm the diagnosis. The gold standard remains biopsy and culture, which enable definitive identification of Mycobacterium tuberculosis .

Management of joint TB begins with multidrug anti-tubercular therapy, which is essential for controlling infection and limiting systemic spread. In cases of advanced articular destruction, however, surgical intervention becomes necessary to alleviate pain and restore function. Arthrodesis remains the most widely performed procedure in such settings, particularly in weight-bearing joints like the ankle, where it is considered the gold standard for stabilizing the joint and providing lasting pain relief. Nonetheless, ankle arthrodesis in the presence of active TB presents unique challenges. Internal fixation introduces the risk of bacterial spread, complicating the surgical course. ^,, Furthermore, data remain limited regarding optimal surgical approaches for managing TB of the ankle joint.

To our knowledge, the use of primary ankle arthrodesis with external fixation for the treatment of ankle joint TB has not been previously reported. In this case report, we describe a rare presentation of ankle tuberculosis successfully managed with external fixation arthrodesis. This approach highlights a potential alternative for treating advanced joint damage due to TB while minimizing risks associated with internal hardware.

A 53-year-old woman presented to the emergency department on May 2, 2020, with a one-week history of left ankle pain. Her past history was notable for a positive PPD in 2014 upon immigrating from India, for which she did not receive treatment; serial chest radiographs at that time were negative. She denied trauma but reported pain with palpation and ambulation of the left ankle.

On presentation, she was afebrile with stable vital signs. Physical examination revealed tenderness over the anterior and posteromedial malleoli and pain with passive range of motion, without significant joint effusion. Radiographs demonstrated no fracture or soft-tissue edema. She was discharged with an ankle brace and hydrocodone–acetaminophen (Norco) for analgesia.

At a clinic follow-up three weeks later, she continued to have persistent pain and was started on naproxen. On June 16, 2020, she returned to the clinic, where additional laboratory tests were obtained. Her serum uric acid was elevated at 8.2 mg/dL. Given these findings and her persistent joint pain, allopurinol and a short course of prednisone were initiated on July 10, 2020, for a presumptive diagnosis of gout.

By September 2, 2020, after one month of allopurinol therapy, she reported approximately 75 % improvement in pain. However, on September 15, 2020, she developed new right ankle pain and persistent left ankle swelling with weightbearing; inflammatory markers, including lab tests for rheumatoid arthritis, were negative. Left ankle radiographs obtained on September 23, 2020, demonstrated joint-space narrowing.

Recurrent left ankle pain on November 25, 2020, prompted an increase in her allopurinol dose. On December 28, 2020, she received a left ankle corticosteroid injection with marked short-term relief; by January 18, 2021, pain was again increasing, and she resumed bracing. In early February 2021, while visiting India, she underwent a left ankle MRI and joint cultures. Joint aspiration revealed leukocytosis and a positive culture, and MRI demonstrated ankle joint erosions and synovitis. The patient was started on rutoside trihydrate, bromelain, trypsin, and ketorolac for 1.5 months while she was in India.

After returning to the US, she was placed on standard anti-tuberculosis therapy (ATT): isoniazid, rifampin, ethambutol, and pyrazinamide for 1.5 months, followed by isoniazid, rifampin, and ethambutol. Infectious Diseases (ID) recommended continuing isoniazid 300 mg, rifampin 600 mg, and ethambutol 1200 mg until mid-June, then transitioning on April 19 to a two-drug continuation phase (isoniazid plus rifampin). Sputum cultures were negative for pulmonary TB. Repeat left ankle MRI showed a large effusion with thick synovitis and erosions (medial and lateral malleoli and lateral tibiotalar joint) with patchy chondral loss; chest CT showed calcifications in the right upper lobe consistent with prior granulomatous disease and a few nonspecific subpleural opacities. After review, ID advised 6–9 months of rifampin/isoniazid/ethambutol and repeat ankle aspiration given the persistent effusion. Surgical versus bracing options were discussed. Because of the chronic course, prolonged ATT (reducing culture yield), and severe cartilage destruction, ankle arthrodesis was considered primarily for symptom relief. The patient demonstrated initial improvement of pain on ATT and consequently declined surgery.

On April 26, 2021, further discussion with ID and the Curry Center recommended histopathologic confirmation from surgical tissue if proceeding with surgery; without surgery, a 12-month regimen (rifampin, isoniazid, ethambutol) was advised. Pyrazinamide was reintroduced for 8 weeks. Three sputum cultures remained negative. At the May 2021 follow-up, MRI findings of significant joint destruction were reviewed, and septic fusion was recommended; the patient elected to observe with semiannual radiographs.

By early October 2021, pain persisted without relief and she agreed to septic ankle fusion; ID cleared her for surgery. Two options were presented: (1) one-stage resection with external fixation (anticipated 2–3 cm limb shortening requiring a permanent shoe lift but shorter frame time) or (2) a two-stage limb-length–preserving approach (stage 1 resection plus external fixator and cement spacer, followed by spacer removal and bone grafting at approximately 5–6 weeks, with the frame maintained for arthrodesis). On October 15, 2021, these options were reviewed with the surgical team; on October 18, 2021, the patient elected the two-stage procedure. She was measured for the external fixator on November 15, 2021, and underwent surgery on November 24, 2021. Intraoperative decision was made to proceed with just a primary fusion of the ankle joint with external fixator rather than performing the two stage procedure based on the amount of viable talus and minimal necrotic tissue present. Subsequently the external fixator was removed on 3/22/2022. Postoperatively, ID recommended continuing ATT through 2022; on December 9, 2021, the plan was to continue therapy through February 19, 2022, and attempt MTB PCR on pathology specimens.

The patient’s postoperative follow up was uncomplicated. She remained non-weightbearing in the external fixator for 8 weeks postoperatively. She began minimal weightbearing in the external fixator shortly after, initially only placing 1–2 steps in the frame and slowly progressed to walking in frame early February 2022. The frame was then dynamized on 2/17 to allow for compression of the frame by unlocking the adjustable struts and placing foot plate and relocking the struts.

In late February 2022 was when initial x-ray imaging showed consolidation of the frame. The patient was placing weight in the frame without much discomfort or pain. At this time the second stage of surgery was planned for March 2022, including removal of the external fixator, debridement of the pin sites and application of a weightbearing fiberglass cast in the operating room. The patient tolerated the procedure well and began weightbearing as tolerated. A CT scan was obtained 3/17 which showed solid bony fusion of the tibiotalar joint. She began to transition out of the boot by late April 2022 into shoes and an ankle brace and subsequently returned to her baseline activity June 2022.