delayed union
Slower than expected bone healing process that may still progress to complete union given time.
Full Definition
Delayed union refers to a fracture healing process that progresses more slowly than the expected timeframe for that particular bone and fracture type, but continues to show signs of healing progression. Unlike nonunion, delayed union implies that healing is occurring but at a reduced rate. Common causes include infection, poor blood supply, inadequate immobilization, smoking, nutritional deficiencies, and certain medications. The diagnosis is typically made when expected healing milestones are not met within the anticipated timeframe, but radiographic evidence of ongoing healing is present.
Usage
Usage note: Distinguish carefully from 'nonunion' (complete failure to heal) and 'malunion' (healing in poor position). Time frames vary by bone location.
In Context
- "At 16 weeks post-injury, imaging revealed delayed union with minimal callus formation." — Follow-up assessment
- "The patient's smoking history likely contributed to the delayed union of the tibial fracture." — Clinical note