A 40-year-old smoker with a tibial shaft fracture asks which habit or drug might impair his fracture healing. Which of the following is a recognised cause of impaired fracture union through inhibition of prostaglandin-mediated inflammatory signalling?

• A Regular use of non-steroidal anti-inflammatory drugs ✓
• B Daily vitamin D supplementation
• C Intermittent paracetamol use
• D Physiological-dose thyroxine replacement

Explanation

NSAIDs inhibit cyclooxygenase enzymes, lowering prostaglandin E2, which is needed for the inflammatory phase of healing, endochondral ossification and callus formation. Animal studies and human cohort data link prolonged high-dose NSAID use to delayed and non-union. Smoking also impairs union, but through nicotine-induced vasoconstriction and reduced oxygen delivery rather than prostaglandin inhibition. Paracetamol and vitamin D do not impair healing.

Reference: Rockwood and Green's Fractures in Adults, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.