‘If it ain’t broke, don’t fix it’ is the approach sometimes taken with gunshot wounds — that is, if removing the bullet would do more harm than good.

But a recent report in the New England Journal of Medicine demonstrates why bullets in the body’s joints should never be left alone, after a man started showing signs of lead poisoning 14 years later.

The 56-year-old presented to a Chicago ED with chronic worsening left knee pain, where he had been shot over a decade earlier.

Radiographs revealed that — in addition to arthritis — the bullet, which was previously embedded in the lateral femoral condyle, had fragmented into tiny metallic particles, and spread throughout his joint and synovium.