Interbody fusion with allograft and rhBMP-2 leads to consistent fusion but early subsidence.
We carried out a prospective study to determine whether the addition of a recombinant human bone morphogenetic protein (rhBMP-2) to a machined allograft spacer would improve the rate of intervertebral body fusion in the spine. We studied 77 patients who were to undergo an interbody fusion with allograft and instrumentation. The first 36 patients received allograft with adjuvant rhBMP-2 (allograft/rhBMP-2 group), and the next 41, allograft and demineralised bone matrix (allograft/demineralised bone matrix group). Each patient was assessed clinically and radiologically both pre-operatively and at each follow-up visit using standard methods. Follow-up continued for two years. Every patient in the allograft/rhBMP-2 group had fused by six months. However, early graft lucency and significant (> 10%) subsidence were seen radiologically in 27 of 55 levels in this group. The mean graft height subsidence was 27% (13% to 42%) for anterior lumbar interbody fusion, 24% (13% to 40%) for transforaminal lumbar interbody fusion, and 53% (40% to 58%) for anterior cervical discectomy and fusion. Those who had undergone fusion using allograft and demineralised bone matrix lost only a mean of 4.6% (0% to 15%) of their graft height. Although a high rate of fusion (100%) was achieved with rhBMP-2, significant subsidence occurred in more than half of the levels (23 of 37) in the lumbar spine and 33% (6 of 18) in the cervical spine. A 98% fusion rate (62 of 63 levels) was achieved without rhBMP-2 and without the associated graft subsidence. Consequently, we no longer use rhBMP-2 with allograft in our practice if the allograft has to provide significant structural support.
Vaidya
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Department of Orthopaedic Surgery, Detroit Receiving Hospital and University Health Center, 4201 St. Antoire Boulevard. 6A, Detroit, Michigan 48201, USA. jean-david.albert@chu-rennes.fr
Weir
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R
Sethi
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A
Meisterling
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Hakeos
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Wybo
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D000293:Adolescent; D000328:Adult; D000368:Aged; D001857:Bone Matrix / Q000503:physiopathology; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011183:Postoperative Complications; D011446:Prospective Studies; D011859:Radiography; D011994:Recombinant Proteins / Q000627:therapeutic use; D012086:Reoperation; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D013118:Spinal Cord Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D013123:Spinal Fusion / Q000379:methods*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D016896:Treatment Outcome
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta