Transforaminal lumbar interbody fusion with rhBMP-2 in spinal deformity, spondylolisthesis, and degenerative disease--part 2: BMP dosage-related complications and long-term outcomes in 509 patients.
METHODS
Retrospective review of prospectively collected data.


OBJECTIVE
Without industry funding, the study evaluated short- and long-term complications related to off-label bone morphogenetic protein (BMP) used with transforaminal lumbar interbody fusion (TLIF) from a large consecutive series. Complications and results were analyzed by BMP dose, fusion length, and primary versus revision surgery. Based on the results, surgical technique and BMP dose recommendations were proposed.


BACKGROUND
Off-label use of BMP in TLIF, although common, has only been studied in small series and case reports using various techniques, cage types, and doses of BMP. Several of these studies have reported minimal complications. Others report problems related to BMP, which has led to questions regarding current widespread use of TLIF with BMP.


METHODS
TLIF with rhBMP-2 was performed at 872 discs in 509 consecutive adults who underwent open posterior instrumented fusion and had minimum 2-year follow-up; diagnoses included degenerative disease (179), spondylolisthesis (207), deformity (123). Patient age averaged 61 years: 12% were smokers and 41% had revision surgery. TLIF was performed at 1.7 levels: single level: 229, 2 levels: 201, 3 levels: 74, 4 levels: 5. Local autograft was used for backfill around and behind each rectangular cage. Varying doses of interbody BMP were used at an average 7.3 mg per disc (range: 2-12 mg per disc).


RESULTS
At 5 years average follow-up, 8 patients developed pseudoarthrosis at levels of TLIF (8 of 872 discs, 0.92%). Seroma (0.4%) and ectopic bone growth (0.6%) were too infrequent to be associated with a particular BMP dose. Deep infection was 2.6% overall (1.7% of the degenerative group). Symptomatic osteolysis or cage subsidence did not occur. Significant long-term improvement was noted in clinical and functional outcomes compared with preoperation.


CONCLUSIONS
Five-year follow-up after TLIF with BMP, independent of industry, confirms effective arthrodesis in short and long fusions, both primary and revision. Most complications occurred in deformity patients. BMP-related complications (seroma, ectopic bone) were rare.


METHODS
3.
Sonoran Spine Center, Phoenix, AZ, USA. dgc@sonoranspine.com
Dennis G
DG
Crandall
Jan
J
Revella
Jason
J
Patterson
Eric
E
Huish
Michael
M
Chang
Ryan
R
McLemore
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055396:Bone Morphogenetic Protein 2 / Q000009:adverse effects / Q000627:therapeutic use*; D001863:Bone Screws; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000628:therapy; D016015:Logistic Models; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology / Q000503:physiopathology; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000175:diagnosis / Q000628:therapy*; D013123:Spinal Fusion / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D013168:Spondylolisthesis / Q000175:diagnosis / Q000628:therapy; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult
D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2