Abstract

Purpose: Artificial bone grafts have been widely used in lumbar decompression and fusion surgery, but intraspinal heterotopic ossification (HO) as a complication is rarely reported. This study presents a rare case of intraspinal HO associated with bioactive glass-based artificial bone powder, leading to restenosis of the spinal canal after lumbar fusion.
Method: A 61-year-old male underwent L4/5 minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar spinal stenosis. During surgery, the intervertebral space was filled with autologous facet joint bone, bioactive glass artificial bone powder, and an interbody cage. Five months postoperatively, the patient developed bilateral lower limb numbness, pain, and walking difficulty. CT scans revealed heterotopic ossification and recurrent spinal canal stenosis. Revision surgery was performed to remove the heterotopic bone mass.
Results: Intraoperative findings showed dense adhesion between the intraspinal HO and the dura mater, nerve roots. The ectopic ossified bone was removed and sent for pathological examination to confirm the bone tissue. Postoperatively, the patient’s symptoms significantly improved, the visual analog scale (VAS) score for pain decreased from 7 to 2, motor function gradually recovered, and independent walking ability was restored.
Conclusion: This case suggests that bioactive glass artificial bone powder may contribute to intraspinal HO following lumbar fusion. Precise surgical techniques to prevent bone powder extravasation into the spinal canal are critical for avoiding such complications. Enhanced postoperative monitoring and surgeon awareness are essential for early detection and timely intervention, thereby reducing the risk of severe neurological deficits.

Keywords

Artificial bone, intraspinal heterotopic ossification (HO), minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), lumbar spinal fusion surgery