In Paget's disease of bone affecting the tibia, the characteristic X-ray finding at the advancing edge of the lytic front is best described as:
- A Pencil-pointing of the cortex
- B Geographic lysis with moth-eaten pattern
- C Blade of grass (V-shaped) lytic lesion advancing from the epiphysis ✓
- D Codman's triangle at the edge
Correct answer: C. Blade of grass (V-shaped) lytic lesion advancing from the epiphysis
Explanation
The advancing lytic front of Paget's disease in long bones has a characteristic V-shaped or 'blade of grass' (also called 'flame-shaped') appearance on X-ray, progressing from the epiphysis toward the diaphysis at a rate of ~1 cm/year. This represents osteolytic phase (osteoporosis circumscripta in the skull, blade of grass in long bones). The mixed/sclerotic phases follow. Geographic lysis with moth-eaten pattern is an aggressive malignancy pattern. Pencil-pointing and Codman's triangle are not Paget's features.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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