A 42-year-old woman presents with medial foot pain and progressive flatfoot deformity. She cannot perform a single-leg heel rise on the affected side. MRI shows thickening and partial tear of a tendon with surrounding edema. Which tendon is involved?
- A Tibialis posterior tendon ✓
- B Peroneus brevis tendon
- C Flexor hallucis longus tendon
- D Spring ligament complex
Correct answer: A. Tibialis posterior tendon
Explanation
Tibialis posterior tendon dysfunction (TPTD) is the most common cause of acquired adult flatfoot deformity. The tibialis posterior supinates the subtalar joint and raises the medial arch during heel rise. Failure to perform a single-heel rise test is the hallmark clinical sign. MRI shows tendon degeneration, thickening, and partial or complete tearing. Staging (Johnson-Strom-Myerson): Stage I = tendinopathy without deformity; Stage II = flexible flatfoot; Stage III = rigid flatfoot; Stage IV = ankle valgus involvement.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.