STUDY DESIGN: A retrospective study. OBJECTIVE: To evaluate whether recombinant human bone morphogenetic protein (rhBMP-2) can improve fusion rates and time to fusion in high-risk patients when compared with autograft in lumbar posterolateral fusion. SUMMARY OF BACKGROUND DATA: The use of rhBMP-2 in the general population for posterolateral fusion has resulted in relatively good reported outcomes; however, it is currently considered "off-label" use. Few studies, however, have determined the outcomes of rhBMP-2 when used in patients with numerous risk factors for a pseudarthrosis. METHODS: One hundred ninety-five patients were divided into 4 groups depending on fusion material and the presence/absence of fusion-related risk factors for nonunions; group A was defined as rhBMP-2 used in the presence of high-risk factors (FRRF), group B was defined as rhBMP-2 used in the absence of FRRF, group C was defined as autograft used in the presence of FRRF, and group D was defined as autograft used in the absence of FRRF. The time to fusion, fusion rate were compared between each group. RESULTS: The time to fusion was significantly faster in group B than in group D in patients with no history of smoking (P<0.05), hypertension (P<0.01), or other significant comorbidity (P<0.05). The time to complete fusion was also significantly faster in group B than in group D in patients under the age of 65 (P<0.05), patients undergoing primary surgery (P<0.05), single-level surgery (P<0.01), no smoking history (P<0.05), no diabetes mellitus (P<0.01), no hypertension (P=0.001), no osteoporosis (P<0.01), and no significant comorbidity (P<0.01). Although the fusion rate was higher in group B than in group D, with the exception of sex and single-level surgery, there were no significant differences between groups B and D. Although initial fusion mass and time to solid fusion was faster in group A than in group C, there were no significant differences between groups A and C. In addition, fusion rates were higher in group C than in group A, looking at all factors except revision surgery, but the differences were not statistically significant. CONCLUSIONS: With relative low dosage of rhBMP-2 compared with the dose used in Food and Drug Administration trial, in patients without fusion-related risk factors, rhBMP-2 may lead to acceptable fusion rates and faster fusion time when compared with autograft. Therefore, rhBMP-2 may serve as an acceptable alternative to autogenous bone graft in patients without fusion-related risk factors undergoing instrumented posterolateral lumbar fusions. When compared with patients with fusion-related risk factors, the use of rhBMP-2 was comparable with autograft but was not sufficient to overcome all aspects of the weakened osteoinductive capacity encountered in patients with these risk factors.
STUDY DESIGN: A retrospective study. OBJECTIVE: To evaluate whether recombinant humanbone morphogenetic protein (rhBMP-2) can improve fusion rates and time to fusion in high-risk patients when compared with autograft in lumbar posterolateral fusion. SUMMARY OF BACKGROUND DATA: The use of rhBMP-2 in the general population for posterolateral fusion has resulted in relatively good reported outcomes; however, it is currently considered "off-label" use. Few studies, however, have determined the outcomes of rhBMP-2 when used in patients with numerous risk factors for a pseudarthrosis. METHODS: One hundred ninety-five patients were divided into 4 groups depending on fusion material and the presence/absence of fusion-related risk factors for nonunions; group A was defined as rhBMP-2 used in the presence of high-risk factors (FRRF), group B was defined as rhBMP-2 used in the absence of FRRF, group C was defined as autograft used in the presence of FRRF, and group D was defined as autograft used in the absence of FRRF. The time to fusion, fusion rate were compared between each group. RESULTS: The time to fusion was significantly faster in group B than in group D in patients with no history of smoking (P<0.05), hypertension (P<0.01), or other significant comorbidity (P<0.05). The time to complete fusion was also significantly faster in group B than in group D in patients under the age of 65 (P<0.05), patients undergoing primary surgery (P<0.05), single-level surgery (P<0.01), no smoking history (P<0.05), no diabetes mellitus (P<0.01), no hypertension (P=0.001), no osteoporosis (P<0.01), and no significant comorbidity (P<0.01). Although the fusion rate was higher in group B than in group D, with the exception of sex and single-level surgery, there were no significant differences between groups B and D. Although initial fusion mass and time to solid fusion was faster in group A than in group C, there were no significant differences between groups A and C. In addition, fusion rates were higher in group C than in group A, looking at all factors except revision surgery, but the differences were not statistically significant. CONCLUSIONS: With relative low dosage of rhBMP-2 compared with the dose used in Food and Drug Administration trial, in patients without fusion-related risk factors, rhBMP-2 may lead to acceptable fusion rates and faster fusion time when compared with autograft. Therefore, rhBMP-2 may serve as an acceptable alternative to autogenous bone graft in patients without fusion-related risk factors undergoing instrumented posterolateral lumbar fusions. When compared with patients with fusion-related risk factors, the use of rhBMP-2 was comparable with autograft but was not sufficient to overcome all aspects of the weakened osteoinductive capacity encountered in patients with these risk factors.
Authors: Aaron W James; Gregory LaChaud; Jia Shen; Greg Asatrian; Vi Nguyen; Xinli Zhang; Kang Ting; Chia Soo Journal: Tissue Eng Part B Rev Date: 2016-04-19 Impact factor: 6.389