Use of polyetheretherketone spacer and recombinant human bone morphogenetic protein-2 in the cervical spine: a radiographic analysis.

Abstract

BACKGROUND CONTEXT:

Results recently reported in the literature have raised some concerns regarding the use of recombinant human bone morphogenetic protein (rhBMP-2) in the cervical spine.

PURPOSE:

We undertook a radiological and clinical review of cervical fusions performed at our institution with polyetheretherketone (PEEK) interbody cage and rhBMP-2.

STUDY DESIGN:

Observational study.

PATIENT SAMPLE:

Perioperative clinical and radiologic data of all patients who underwent an anterior cervical discectomy and fusion using PEEK and rhBMP-2 for cervical spondylotic radiculopathy or myelopathy were collected.

OUTCOME MEASURES:

Images were examined for fusion, heterotopic ossification, end-plate resorption, subsidence, and segmental sagittal alignment.

METHODS:

All patients underwent detailed postoperative radiologic analysis using a computed tomography (CT) scan obtained at least 6 months postoperatively and plain X-rays obtained at regular intervals.

RESULTS:

Twenty-two patients had 38 levels fused using PEEK and varying doses of rhBMP-2. No anterior cervical swelling requiring additional procedures or longer than anticipated hospital stays occurred. Pseudoarthrosis, shown as a horizontal radiolucent fissure through the midportion of the PEEK cage on CT, occurred in four patients. Excessive bone growth into the spinal canal or foramina occurred in 26 (68%) patients but did not result in neurologic sequelae. Cystic regions in the core of the PEEK spacer were seen in most patients, with 15 levels (39%) having cysts measuring 3mm or greater. Moderate or severe osteolysis of the end plates occurred in 57% of levels, and this led to subsidence of the construct and loss of some of the segmental sagittal alignment (ie, lordosis) that had been achieved with surgery.

CONCLUSIONS:

The unlimited supply of PEEK spacers and rhBMP-2 and their ease of use make them attractive platforms to achieve fusion. This study has demonstrated that the fusion process using rhBMP-2 is a dynamic one, with osteolysis dominating the initial phase, leading to end-plate resorption and consequently loss of some of the disc space height and sagittal alignment that was achieved with surgery. There is a high incidence of bone growth beyond the core of the PEEK spacer and cystic regions within the cage. Given our experience, we currently reserve the use of PEEK and rhBMP-2 for use in those patients who are at greatest risk of pseudoarthrosis.

• Authors: Paul Klimo Jr, Michael W Peelle
• Journal: The spine journal : official journal of the North American Spine Society (Spine J) Vol. 9 Issue 12 Pg. 959-66 (Dec 2009) ISSN: 1878-1632 [Electronic] United States
• PMID: 19574105 (Publication Type: Journal Article)

Chemical References

• Benzophenones
• Bone Morphogenetic Protein 2
• Bone Morphogenetic Proteins
• Ketones
• Polymers
• Recombinant Proteins
• Transforming Growth Factor beta
• recombinant human bone morphogenetic protein-2
• polyetheretherketone
• Polyethylene Glycols

Topics

• Adult
• Aged
• Benzophenones
• Bone Cysts
• Bone Morphogenetic Protein 2
• Bone Morphogenetic Proteins (adverse effects)
• Bone Plates (adverse effects)
• Cervical Vertebrae (diagnostic imaging, surgery)
• Female
• Humans
• Ketones (adverse effects)
• Male
• Middle Aged
• Osseointegration
• Ossification, Heterotopic
• Osteolysis
• Polyethylene Glycols (adverse effects)
• Polymers
• Postoperative Complications (etiology)
• Prosthesis Failure
• Pseudarthrosis
• Radiography
• Recombinant Proteins (adverse effects)
• Spinal Fusion (adverse effects, instrumentation, methods)
• Transforming Growth Factor beta (adverse effects)