Propranolol enhances bone healing and implant osseointegration in rats tibiae

Background: Propranolol, a non-selective beta-blocker widely used to treat cardiovascular conditions, favours bone accrual. Accordingly, we hypothesized that propranolol could be useful for improving bone healing and osseointegration. This in vivo study was designed to investigate the effect of propranolol on bone healing and osseointegration in rats' tibiae. Methods: On 24 Sprague-Dawley rats, a unicortical defect was created in the right tibial metaphysis of each rat and a custom-made titanium implant was placed in the left tibia. Animals were then assigned into two groups (n = 12, each group) and treated daily with either propranolol (5 mg/kg: subcutaneous) or saline, for 2 weeks. Then, after killing, the volume of the cortical defects (mm(3)) and the percentages of newly formed bone in the defects, were assessed with microcomputed tomography; bone-implant contact percentage and peri-implant bone volume/tissue volume were assessed by histomorphometry. Result: Propranolol-treated rats presented smaller cortical defects (1.56 +/- 0.28 mm(3) versus 2.04 +/- 0.29 mm(3), p < 0.001) with more bone volume/tissue volume (60.6 +/- 7.9% versus 41.1 +/- 10.2%, p < 0.001) compared to saline-treated rats. Propranolol also enhanced osseointegration as propranolol-treated rats presented higher bone-implant-contact (65.0 +/- 13.1% versus 42.5 +/- 8.8%, p < 0.001) and peri-implant bone volume/Tissue volume (73.8 +/- 10.1% versus 56.9 +/- 5.7%, p = 0.007) than saline-treated rats. Conclusion: Propranolol enhanced bone healing and implant osseointegration.