A Surgical Procedure for Resecting the Mouse Rib: A Model for Large-Scale Long Bone Repair

Abstract

This protocol introduces researchers to a new model for large-scale bone repair utilizing the mouse rib. The procedure details the following: preparation of the animal for surgery, opening the thoracic body wall, exposing the desired rib from the surrounding intercostal muscles, excising the desired section of rib without inducing a pneumothorax, and closing the incisions. Compared to the bones of the appendicular skeleton, the ribs are highly accessible. In addition, no internal or external fixator is necessary since the adjacent ribs provide a natural fixation. The surgery uses commercially available supplies, is straightforward to learn, and well-tolerated by the animal. The procedure can be carried out with or without removing the surrounding periosteum, and therefore the contribution of the periosteum to repair can be assessed. Results indicate that if the periosteum is retained, robust repair occurs in 1 -2 months. We expect that use of this protocol will stimulate research into rib repair and that the findings will facilitate the development of new ways to stimulate bone repair in other locations around the body. Video LinkThe video component of this article can be found at

Sox9+ messenger cells orchestrate large-scale skeletal regeneration in the mammalian rib

“…Like appendicular long bones, the bony portion of the rib develops via an endochondral process including growth plates at either end and a central hollow bone marrow cavity. Both human and murine rib bones display remarkable regenerative potential (Srour et al, 2015; Tripuraneni et al, 2015), however the cellular basis for such large-scale repair remains unknown. To better understand the cellular sequence of events during regeneration, we analyzed 3 mm rib bone defects at sequential time points up to 10 weeks post-resection (wpr) (Figure 1A).…”

“…We next examined the source of the skeletal cells that mediate repair. These cells are likely derived from the periosteum, since removal of the periosteum along with the bone, results in a failure of cartilage callus formation (Figure 2—figure supplement 1) and subsequent bone repair (Tripuraneni et al, 2015). Sox9 is a master regulatory gene of chondrogenesis, and a previous study indicated that Sox9+ cells in the femur periosteum can contribute to callus formation after fracture (He et al, 2017).…”

“…Rib resections were performed as previously described (Tripuraneni et al, 2015) with the modification that a bone segment of 3 mm was removed and that post-operative pain was managed with buprenorphine SR (ZooPharm) at a dose of 0.5 uL/gram. Rib repair was assessed after set healing time points: 0 dpr – 10 wpr.…”

“…Craniofacial surgeons often extract large segments of rib cartilage and bone for autologous repair of skeletal defects in other parts of the body, and in post-operative visits have noted extensive regeneration at the donor rib site (Kawanabe and Nagata, 2006; Munro and Guyuron, 1981; Srour et al, 2015). To better understand the unique regenerative potential of the rib, we have recently developed analogous large-scale rib cartilage and bone regeneration models in the mouse (Srour et al, 2015; Tripuraneni et al, 2015).…”

“…During skeletal repair, studies have shown that cells from the periosteum, a heterogeneous connective tissue sheath covering the bone, are major contributors to the callus (Colnot, 2009; Duchamp de Lageneste et al, 2018; Murao et al, 2013). Accordingly, we have found that the periosteum is essential for regeneration of the rib bone (Tripuraneni et al, 2015).…”