Would it Possible to Turn Muscle into Bone?

The challenge of treating large osseous defects presents a formidable problem for orthopedic and maxillofacial surgeons. The present method of choice to replace lost tissue is autologous bone grafting, but supplies of autologous bone are limited and harvesting of the graft is associated with donor site morbidities [1]. Artificial biomaterials offer much promise, but do not, by themselves, supply the osteo-progenitor cells needed for bone formation. Moreover, there are often issues with resorption of the scaffold used in the biomaterial, coupled with inadequate vascularization. To address this shortfall, the use of a muscle flap that can act as a bio-reactor for the growth of mesenchymal stromal cells, which can then provide a composite bone mineral for maxillofacial reconstruction has been reported [2]. The role of muscle in bone regeneration has not been studied extensively, however there is proof that muscle has the propensity to induce bone formation because of its intrinsic osteogenic potential when exposed to osteogenic stimuli including bone matrix substitutes and bone morphogenic proteins [3-5]. The most accepted mechanism behind bone formation is that an inflammatory response at the surgical site, and the presence of oestrogenic stimuli amplify the signalling of exogenous BMP-7, triggers the MAPK pathway, as explained by Hassel et al. [6].