SLR - November 2011 - Chanel Houston

Tuberculosis of the foot and ankle in children

Reference:  Agarwal, A., Akhtar, N., Khan, S.A., Kumar, P., Samaiya, S. Tuberculosis of the foot and ankle in children. Journal of Orthopaedic Surgery 2011;19(2):213-7

Scientific Literature Review

Reviewed by: Chanel Houston, DPM
Residency Program: Yale New Haven/DVA Healthcare System

Podiatric Relevance:
The manifestation of tuberculosis in the foot and ankle is relatively uncommon and oftentimes results in a delayed diagnosis due to non-specific clinical and radiological findings.  This article focused on the diagnosis and management of tuberculosis of the foot and ankle in the pediatric population. 

Methods:
In a retrospective study, a total of 21 pediatric patients (12 girls and 9 boys) ranging in age from 3 to 14 years were reviewed.  All patients had local swelling, tenderness, and an antalgic gait.  Sixteen patients presented with limping, 5 patients had a preceding trauma, 11 patients had an abscess, and 6 patients had a discharging sinus.  The delay in presentation of these symptoms was an average of 4.7 months.  Fine needle aspiration cytology was done on all patients presenting with an abscess.  A trocar bone biopsy was done for those patients with osseous lesions.  For patients with joint involvement, an open biopsy to collect synovial and bone specimens was conducted.  An edge biopsy of sinuses was performed on all patients presenting with discharging sinuses.  Each specimen obtained was subjected to acid-fast staining and histopathological examination.  The final diagnosis of tuberculosis was based on a smear positive for acid-fast bacilli, histopathology, or clinicoradiological findings.  Lesions were classified as either synovial or osseous.  There were 3 synovial lesions, all of which occurred in the ankle.  Osseous lesions involved the calcaneus, metatarsal, cuboid, phalanx, talus, and medial cuneiform.  Although pulmonary tuberculosis was not evident in this population, 9 patients were found to have osteoarticular tuberculosis involving other body parts.

Results:  
All lesions were generally classified as either synovial or osseous, with osseous lesions sub-categorized into 3 different stages based on disease propagation.  Stage 1 lesions presented clinically as soft tissue swelling only, with minimal radiographic changes such as osteopenia.  Stage 2 lesions were consistent with abscess formation clinically in addition to osteopenia, osteolysis, sequestrum, and cystic changes radiographically.  Stage 3 lesions were categorized clinically by soft tissue swelling, abscess, and discharging sinuses.  Radiographic interpretation of a stage 3 lesion involved osteopenia, joint destruction, and diffuse sclerosis.  Treatment was conservative in the form of splintage and multidrug chemotherapy.  All patients with ankle lesions were immobilized for 4 weeks, while patients with foot lesions were immobilized for 3 weeks.  Patients with advanced lesions (stage 3) were non-weightbearing for 10 weeks.  Isoniazid, Rifampin, Ethambutol, and Pyrazinamide were administered as chemotherapeutic agents for 2 months followed by Isoniazid and Rifampin for another 10 months. There was a 21 month follow-up period.  Painful symptoms usually subsided after 3 to 4 weeks of treatment.  Three patients with stage 1 osseous lesions healed in 6 weeks with complete recovery of function.  Four patients with stage 3 lesions healed by 6 months.  Patients with stage 3 lesions had delayed healing.  Overall, no patients had residual tenderness or deformity at follow up. 

Conclusions
Tubercular lesions in the foot and ankle can be classified into granulomatous foci, central granuloma, hematogenous synovitis, or bursal tuberculosis.  Classifications can also include cystic, rheumatoid, or subperiosteal.  Furthermore, tubercular osteomyelitis in children can be classified as cystic, infiltrative, focal erosion, or spina ventosa.  If lesions are diagnosed and treated early, conservative treatment has good results; however, it is important to understand that a delay in diagnosis may very well result in an advanced disease with poor prognostic outcomes.   Longer follow-up studies and a larger patient population are still needed to fully determine recurrence and overall results of pedal tuberculosis in the pediatric patient base.

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