Some patients exposed to rhBMP-2 may develop heterotopic bone after spinal fusion

ORLANDO, Fla. — During a 2.5-year period, nearly 3% of patients who underwent thoracic or lumbar spinal fusion developed formations of ectopic recombinant human bone morphogenetic-2 protein bone that were not easily detectable on plain CT scans at 1 month to 3 months after the procedure, according to findings of a study presented at Spine Summit 2016: CNS/AANS Section on Disorders of the Spine & Peripheral Nerves Annual Meeting.

Kenneth M. Crandall, MD, and colleagues evaluated 258 patients who underwent thoracic and/or lumbar fusion with recombinant human bone morphogenetic-2 protein (rhBMP-2). Seven of the 258 patients (2.7%) required surgical exploration and the removal of heterotopic bone formation at variable time intervals following their initial procedure.

Kenneth M. Randall

“From this standpoint from comparing histology to radiography in our few patients that were between 2 [months] and 5 months, the area of bone that we sampled was hypodense on CT scan with lower Hounsfield units compared to later on, suggesting that there are time-dependent, radiographic and histologic changes you may not be able to see easily on CT scans,” Crandall said at the meeting.

Crandall noted more advanced MRI and invasive CT myelograms were better able to visualize the formation of immature, heterotopic rhBMP-2 bone within 18 months of implantation. – by Robert Linnehan

For more information:

Crandall KM, et al. Paper #316. Presented at: Spine Summit 2016: CNS/AANS Section on Disorders of the Spine & Peripheral Nerves Annual Meeting; March 16-19, 2016; Orlando, Fla.

Disclosure: Crandall reports no relevant financial disclosures.