1. Imaging Findings

Based on the provided X-ray and MRI images, the main findings are as follows:

• X-ray (Left Hand): In the proximal phalanx of the left little finger, an obvious fusiform expansion is noted, with thinning of the cortical bone and cystic-like destruction, resembling a “blown-out” appearance. Adjacent soft tissue swelling is present, but no clear fracture line is visible. The joint space is still preserved, and there are no obvious loose bone fragments or major bony fragmentation observed at this time.
• Chest X-ray: No obvious large infiltrative lesions or cavity formations are seen. If evaluating for potential pulmonary tuberculosis lesions, further clinical correlation and additional tests (e.g., TST/IGRA and chest CT) are recommended.
• MRI (Left Little Finger): T1/T2-weighted images show abnormal signal within the bone marrow of the proximal phalanx, with diffusely increased signal intensity. A certain degree of soft tissue swelling is present in the surrounding tissues. No extensive abscess formation is detected, though localized soft tissue involvement with signal enhancement is observed, consistent with chronic infection or granulomatous inflammation.

2. Potential Diagnoses

Considering the patient’s history (over one year of progressive, painless swelling of the left little finger starting in childhood) and the short tubular bone expansion shown on the imaging, the main differential diagnoses include the following:

• Tuberculous Dactylitis (Tuberculous Osteomyelitis / “Spina Ventosa”): Typically presents as a fusiform expansion of short tubular bones with thinning of the cortex, often involving adjacent soft tissues. It commonly occurs in early childhood and is the primary consideration here.
• Chronic Suppurative Osteomyelitis: Usually involves pain or recurrent acute exacerbations. Imaging often shows significant destructive changes with sequestra or cavities. In this case, the lack of pronounced pain and the absence of sequestral changes on X-ray make this diagnosis less likely.
• Fungal Infection: Relatively rare; certain fungi can cause chronic bone destruction, but they are often associated with systemic symptoms or an immunocompromised background.
• Benign Bone Tumors or Tumor-like Lesions (e.g., enchondroma, fibrous dysplasia): These conditions may show localized expansion or characteristic calcifications, but their growth patterns and imaging features differ from the “cystic expansion” seen in this case.

3. Final Diagnosis

Taking into account the patient’s age (11 years), clinical presentation (painless, persistent swelling of the finger), the “cyst-like” expansion noted in imaging, and the higher incidence of Mycobacterium tuberculosis infection in developing countries (e.g., India), the most likely diagnosis is tuberculous dactylitis (tuberculous osteomyelitis, commonly referred to as “Spina Ventosa”). However, definitive confirmation necessitates obtaining pathological samples from the lesion or demonstrating Mycobacterium tuberculosis through culture or PCR testing.

4. Treatment and Rehabilitation Plan

Treatment Plan:

• Anti-tuberculosis Therapy: If confirmed by biopsy or microbiological testing, standard anti-tuberculosis regimens (commonly including isoniazid, rifampin, pyrazinamide, and ethambutol) for 6–9 months or longer should be administered. The specific duration and regimen are determined by a specialist based on drug resistance patterns and clinical response.
• Local Immobilization and Splinting: In the acute phase of inflammation or in cases of significant bone destruction, small splints or protective devices may be used to reduce stress and prevent deformity.
• Surgical Intervention: If marked bone collapse, joint destruction, or large abscess formation occurs along with significant functional impairment, surgical debridement and bone graft reconstruction might be considered. However, in many cases, early anti-tuberculosis medication can minimize or avoid the need for surgery.

Rehabilitation and Exercise Prescription:

Once infection control reaches a stable phase or during the later stages of treatment, gradual functional training should be introduced. The following FITT-VP principles may be applied:

• Frequency: Perform hand rehabilitation exercises 3–5 times per week, adjusting according to clinical progress.
• Intensity: Begin with exercises that do not cause pain, such as low-resistance grip ball exercises or trunk-to-upper-limb coordination drills. Avoid excessive stress or overloading on the affected finger.
• Time: Each exercise session can start at 10–15 minutes and be gradually prolonged as tolerated.
• Type: Focus on active range-of-motion and joint flexibility exercises first. In the intermediate to late stages, gently introduce resistance exercises (e.g., resistance bands or grip trainers). At the same time, maintain overall physical fitness to enhance immunity.
• Progression: As local pain, swelling, and inflammation subside, carefully increase the difficulty and load of the exercises, gradually transitioning toward higher-intensity joint mobility and muscle-strengthening activities.

During rehabilitation, closely monitor the affected finger for worsening pain, redness, or range-of-motion limitations, and seek prompt evaluation to rule out flare-ups or progression of the disease.

Disclaimer: This report is a reference analysis based on the current imaging and clinical information and is not intended as a definitive basis for diagnosis or treatment. Actual diagnosis and therapy should be determined by a professional physician through in-person evaluation and further investigations.