Ectopic Laryngeal Ossification after Bone Morphogenetic Protein-2

Area of Science:

• Otolaryngology
• Orthopedic Surgery
• Biomaterials Science

Background:

• Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a potent osteoinductive agent used in various surgical applications.
• Previous studies have documented ectopic bone formation and adverse events, such as swelling and dysphagia, following rhBMP-2 use, particularly in cervical spine surgery.

Purpose of the Study:

• To report two distinct cases of ectopic bone formation in the head and neck region after rhBMP-2 treatment.
• To highlight the potential risks associated with rhBMP-2, emphasizing the need for careful dosing and increased clinical awareness.

Main Methods:

• Case report methodology involving detailed review of surgical pathology.
• Utilized laryngoscopy and CT imaging for diagnostic assessment.
• Compiled comprehensive patient medical histories.

Main Results:

• Case 1: A 67-year-old male developed osseous metaplasia in the vocal fold post-mandibular dental implants with rhBMP-2.
• Case 2: A 73-year-old male experienced severe laryngeal bony overgrowth and anterior cervical spine (ACS) fusion after multiple anterior cervical discectomies and fusions with rhBMP-2.
• Both cases presented unusual patterns of abnormal bone growth in soft tissue areas of the head and neck.

Conclusions:

• The presented cases strongly suggest a link between rhBMP-2 application and ectopic bone formation in the head and neck.
• Clinicians should be aware of these potential adverse effects, especially concerning the use of rhBMP-2 in cervical spine and dental procedures.
• Caution in rhBMP-2 dosing is strongly recommended to mitigate risks of abnormal bone growth.