A 35-year-old man with a supracondylar femur fracture undergoes ORIF. At 6 months, X-ray shows bridging callus on three cortices but persistent fracture line on one cortex. There is no pain. This is classified as:

• A Delayed union — acceptable and likely to consolidate with continued observation ✓
• B Established non-union requiring bone grafting
• C Hypertrophic non-union requiring dynamization
• D Infected non-union requiring debridement

Explanation

Delayed union means healing is slower than expected but is progressing — radiological evidence of callus on at least three cortices with an incomplete fracture line on one cortex at 6 months indicates the fracture is still healing, not stuck. Non-union is typically declared when there is no progressive radiographic change for three consecutive months (or no healing by 6–9 months for long bones). Here, bridging callus on 3 cortices confirms active osteogenesis; continued observation is appropriate. Hypertrophic non-union shows exuberant callus with a persistent fracture gap — indicating mechanical instability, treated by dynamization or revision fixation. Atrophic non-union lacks callus entirely.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

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Written and medically reviewed by the StethoPrep medical team.