Occipitocervical fusion using recombinant human bone morphogenetic protein-2: adverse effects due to tissue swelling and seroma.

STUDY
DESIGN: Case presentation and literature review.
OBJECTIVE: To review the safety of using INFUSE bone graft (recombinant human bone morphogenetic protein-2 applied to an absorbable collagen sponge) in occipitocervical (OC) fusion. SUMMARY OF BACKGROUND DATA: Although INFUSE bone graft is currently approved for use in certain tibial fractures, oral maxillary procedures, and anterior lumbar interbody fusion, it has been extensively used "off-label" in posterolateral lumbar and anterior cervical fusions. INFUSE is highly effective in promoting cervical spine fusion via an anterior approach, but its potential role in promoting bony fusion in posterior cervical or OC fixation has not been studied.
METHODS: A 53-year-old woman with basilar invagination underwent OC fixation using INFUSE bone graft. Three days after surgery she experienced neurologic decline associated with significant tissue swelling and a large postoperative seroma under significant pressure. She made excellent recovery after reoperation and drainage. An extensive review of the literature was performed to propose a modified approach to the use of INFUSE in OC fixation.
RESULTS: Proper dosing and delivery of INFUSE for posterior cervical/OC fixation is not currently known. Previously published experience with anterior cervical fusion suggests that INFUSE can have potent inflammatory effects on paraspinal soft tissue.
CONCLUSION: INFUSE should only be used for OC fixation in patients at elevated risk of nonunion. To prevent complications due to soft tissue swelling, consideration should be given to preventing direct exposure of INFUSE to paraspinal musculature, prolonged soft tissue drainage, and prophylactic treatment with perioperative steroid therapy.