Bone morphogenetic protein-2 (BMP-2) in the treatment of pyogenic vertebral osteomyelitis.
METHODS
Retrospective case series.


OBJECTIVE
To present results of recombinant human bone morphogenetic protein-2 (rhBMP-2) use in medically nonresponsive pyogenic vertebral osteomyelitis (PVO), treated by anterior/posterior debridement and instrumented fusion in the cervical, thoracic, and lumbosacral spine.


BACKGROUND
Surgical options for PVO vary, as do their outcomes, and can be complicated by recurrence, pseudarthrosis, and death. Although rhBMP-2 use in spinal fusion is increasing, its utility in PVO is unknown. Additionally, use in areas of infection is listed as a contraindication, although this is not supported by laboratory (animal) studies or clinical studies in long bones.


METHODS
Between 2003 and 2005, 14 patients who underwent circumferential fusion for PVO were included in this study. Average patient age was 54 years (range, 27-77 years). Eight (57%) patients had 3 or more vertebral bodies involved. Diagnostic studies included radiographs, CT, MRI, and markers of infection [(C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood count (WBC)]. All patients underwent anterior fusion with rhBMP-2 inserted in structural allograft (11 patients) or titanium cylindrical cages (3 patients), followed by posterior instrumented fusion with autogenous iliac crest graft (8 occurring on the same day). Follow-up averaged 22 months (range, 11-30 months). All were studied with plain radiographs, including flexion-extension lateral films and fine cut CT scans with reconstruction. Pain ratings were recorded by visual analog scores (VAS).


RESULTS
Clinical resolution of infections, normalization of lab values, and bony fusion, based on dynamic radiographs and CT scans, were seen in all patients at latest follow-up. Staphylococcus aureus was the most frequently identified organism (8 patients). Four (29%) patients had positive blood cultures (all MRSA). Predisposing comorbidities were present in 12 patients. Six patients had epidural abscesses. Eight (57%) patients presented with neurologic deficits, ranging from paraparesis to quadriplegia. Complete recovery was seen in 7 (quadriplegia unchanged). At 1 year, mean VAS pain scores improved significantly (P < 0.05) from 7.9 (range, 3-10) to 2.8 (range, 0-6). Perioperative complications (non-BMP related) occurred in 2 patients. There were no surgically-related deaths.


CONCLUSIONS
rhBMP-2 use, in combination with antibiotics and circumferential instrumented fusion, provides a safe and successful surgical treatment of medically nonresponsive PVO, with solid fusions obtained, good clinical results, and no adverse side effects from the BMP.
Allen
R Todd
RT
Department of Orthopaedic Surgery, University of California-San Diego, San Diego, CA 92103-8894, USA.
Lee
Yu-Po
YP
Stimson
Elizabeth
E
Garfin
Steven R
SR
D000328:Adult; D000368:Aged; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000382:microbiology / Q000601:surgery; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000382:microbiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000382:microbiology / Q000601:surgery; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*; D016896:Treatment Outcome
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta