Bone consolidation is enhanced by rhBMP‐2 in a rabbit model of distraction osteogenesis

Abstract

Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) is a differentiation factor which has been shown to induce bone formation and heal bony defects in a variety of animal models. A possible application of rhBMP‐2 is to accelerate bone regeneration during distraction osteogenesis, which clinically is a long procedure, often involving significant complications. In this study we tested the ability of rhBMP‐2 to accelerate the consolidation phase of distraction osteogenesis in a rabbit model of leg lengthening. Tibiae were lengthened 2 cm over a period of ten days. rhBMP‐2 was administered at the end of the lengthening phase. Two modes of rhBMP‐2 application were tested: surgical implantation of rhBMP‐2/ACS (absorbable collagen sponge) into the regenerate (50 μl of 1.5 mg/ml rhBMP‐2, total dose = 75 μg rhBMP‐2), and percutaneous injection of rhBMP‐2/buffer (0.1 ml of 0.75 mg/ml rhBMP‐2, total dose = 75 μg rhBMP‐2) into three sites within the regenerate. Also, there were three groups of control animals: (1) no surgical intervention, (2) surgical implantation of buffer/ACS and (3) percutaneous injection of buffer. Rabbits were sacrificed at 5, 14 and 28 days after the interventions. Radiographic evaluation indicated a significant increase in bony union of the distraction regenerate in the rhBMP‐2 treated groups compared with the untreated groups at 5 and 14 days. At 28 days, formation of a cortex and reestablishment of the medullary canal was evident only in the rhBMP‐2 treated groups. The bone mineral content (BMC) of the regenerate was significantly higher in the rhBMP‐2 treated groups at 5 and 14 days. However, at 28 days, BMC of the regenerate was similar in all groups. The average volumetric density of the regenerate was significantly higher in the rhBMP‐2 injection group at day 14. In summary, both injection of rhBMP‐2/buffer and implantation of rhBMP‐2/ACS enhanced the consolidation stage of distraction osteogenesis in this rabbit model. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.

Delayed administration of adenoviral BMP-2 vector improves the formation of bone in osseous defects

“…The total BMC was measured within a region of interest that included only the defect zone. 23 By assessing the total mineral content rather than the area bone mineral density, errors associated with positioning were minimized.…”

Reindeer BMP extract in the healing of critical-size bone defects in the radius of the rabbit

“…The bone-inducing capacity of reindeer BMP extracts was compared to untreated controls and collagen-treated controls, while rhBMP-2 (InductOs) was studied as a reference because its bone-healing capacity is well documented (Hollinger et al1998, Sciadini and Johnson 2000, Yudell and Block 2000, Govender et al 2002, Li et al 2002.…”

Effect of intermittent administration of adiponectin on bone regeneration following mandibular osteodistraction in rabbits

“…13 Quick distraction protocol was usually used to simulate a poor 14, 15 The short latency period (3 days) and rapid distraction rate (2 mm/day) applied in the current study was proven to induce immature bone regeneration, which was in accordance to the previous studies. 14,15 Further study attributed the poor result to the decrease of necessary growth factors that retarded or completely inhibited bone regeneration and subsequent healing. 16,17 Therefore, osteoinductive or angiogenic growth hormones or proteins were usually adopted to promote bone regeneration and shorten healing time.…”