Effect of Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) with Hydroxyapatite Carrier in Induced Membrane Technique: A Retrospective Propensity Score-matched Study.

OBJECTIVES To determine the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) with hydroxyapatite (HA) carrier augmentation in managing critical-sized bone defect (CSBD) with induced membrane technique (IMT). DESIGN Retrospective comparative study. SETTING Academic level I trauma center.Patients/Participants: The study included 14 patients who underwent rhBMP-2 with HA carrier (rhBMP-2/HA) augmentation in IMT for managing CSBD (BMP group). Moreover, 14 patients who underwent IMT without rhBMP-2 augmentation were matched by propensity score analysis (non-BMP group). INTERVENTION IMT with or without rhBMP-2/HA augmentation. MAIN OUTCOME MEASUREMENT Changes in quality and quantity measurements of grafted bone to regenerated bone using serial computed tomography. RESULTS In the BMP and non-BMP groups, the changes in densities from grafted bone to regenerated bone were +379.63 Hounsfield unit (HU) and +248.55 HU (P = 0.034), changes in dense bone percentage were +37.52% and +23.31% (P = 0.027), corticalization rates under the plate were 79.70% and 39.30% (P = 0.007), changes in volume were -20.77% and -23.35% (P = 0.812), union rates were 85.71% and 78.57% (P = 0.622), numbers of patients requiring additional procedures were 4 and 3 (P = 0.663), and time to union were 316.3 and 585.45 days (P = 0.040), respectively. CONCLUSIONS RhBMP-2/HA augmentation increases the density of regenerated bone, enhances corticalization under the plate, and shortens the time to union while managing CSBD with IMT.