As if falling off a bike isn’t painful enough, imagine bones growing on your injured muscles.

For hundreds of thousands of people, this complication is actually quite common, but researchers from Northwestern University Feinberg School of Medicine and the Perelman School of Medicine at the University of Pennsylvania, have learned what causes this abnormal bone growth, which currently has no treatment.

As their studies showed, a neuropeptide in the brain known as Substance P appears to trigger the formation of the extraskeletal bone, but through its elimination, this abnormal growth, also known as heterotopic ossification, can be prevented.

With this discovery, scientists are hopeful that new drugs can be developed to treat and prevent this complication, which typically happens after a minor accident.

“Patients who have it become very uncomfortable, and there is no way to make it go away,” said Dr. Jack Kessler, chair of neurology at Northwestern’s Feinberg School and the senior author of the paper, which was published in the Journal of Cellular Biochemistry. “This explains why it happens and gives us a way to develop a therapy to potentially treat it.”

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