Ordinary anti-inflammatories showed no link to a break failing to knit
Across 339,864 fracture episodes, non-selective drugs sat at odds of 1.07 and COX-2 inhibitors at 1.84. Opioids sat at 1.69, with no bone-healing mechanism to explain it.
What the study found
After a fracture the class splits: COX-2 drugs 1.84, the rest 1.07
Across 339,864 fracture episodes, non-selective non-steroidal anti-inflammatory drugs, or NSAIDs, showed no association with a break failing to knit, at odds of 1.07. COX-2 inhibitors, the newer type sparing the COX-1 enzyme, went with 1.84 times the odds of needing corrective surgery.
The caveat · Opioids showed a similar link
Opioids showed a similar association, at 1.69, with no proposed bone-healing mechanism at all, which points at more painful or more severe fractures attracting stronger prescriptions rather than at the drugs themselves. Prescriptions filled stand in for drugs actually swallowed, and anything bought over the counter is invisible, which weakens the non-selective comparison specifically. Nonunion was rare, following 0.9% of episodes, so these odds sit on small absolute numbers.