Comparison of the healing of open tibial fractures covered with either muscle or fasciocutaneous tissue in a murine model

Abstract

The objective of this study was to compare the effects of soft tissue coverage by either muscle or fasciocutaneous tissue on the healing of open tibial fractures in a murine model. An open tibial fracture, stripped of periosteum with intramedullary fixation, was created in mice. Experimental groups were devised to allow exclusive comparison of either muscle alone or skin plus fascia in direct contact with healing bone. To exclusively assess the relative efficacy of muscle and fasciocutaneous tissue to promote healing of a fracture stripped of periosteum, a piece of sterile inert material (polytetrafluoroethylene) was positioned anteriorly, excluding skin and fascia (muscle group) or posteriorly, excluding muscle (fasciocutaneous group). Skeletal repair was assessed histologically and quantified by histomorphometry; quantitative peripheral computed tomography (pQCT) and mechanical testing using a four-point bending technique. This standardized, reproducible model allowed characterization of the morphology of open fracture healing. At 28 days postfracture, there was faster healing in the experimental muscle coverage group compared to skin and fascia alone. Furthermore, there was almost 50% more cortical bone content and a threefold stronger union beneath muscle compared to fasciocutaneous tissue (p < 0.05 by one-way ANOVA). Exclusive comparison of muscle and fasciocutaneous tissue in our novel murine model demonstrates that muscle is superior for the coverage of open tibial fractures for both the rate and quality of fracture healing. ß

TNF-α promotes fracture repair by augmenting the recruitment and differentiation of muscle-derived stromal cells

“…All work was undertaken with ethical approval and patient consent. Our murine model has been published previously (20).…”

“…A 50% increase in cortical bone content and threefold stronger union at 28 d was observed when fractured tibiae were in direct contact with muscle exclusively, as opposed to fasciocutaneous tissue. This result occurred despite a greater vascularity in the fasciocutaneous tissue at all time points (20,21), suggesting that tissue factors influence the healing process.…”

“…The influence of fractured bone on adjacent muscle was investigated using our murine model of a periosteally stripped (high-energy) open tibial fracture (20). At day 3, cells isolated from muscle adjacent to the fracture were harvested, cultured for 7 d, and then fixed and stained for alkaline phosphatase (ALP), a surrogate marker of early osteogenic differentiation.…”

“…Thus, contributions from adjacent skeletal muscle (9,13,14), fat (15), and skin (16) may be vital (17)(18)(19). We have previously compared the effect of muscle with fasciocutaneous tissue in exclusive contact with fractured, periosteally stripped, and endosteally reamed bone in a murine model of open fracture (20). A 50% increase in cortical bone content and threefold stronger union at 28 d was observed when fractured tibiae were in direct contact with muscle exclusively, as opposed to fasciocutaneous tissue.…”

Tumor necrosis factor-α triggers a cytokine cascade yielding postoperative cognitive decline

“…We performed an open tibial fracture as previously described (51). Briefly, we anesthetized mice with 2.1% isoflurane and analgesia with buprenorphine (Buprenex, 0.1 mg/kg s.c).…”