Use of the Hybrid Operating Room for Pelvic and Acetabular Fracture Surgery.

The hybrid operating room (HOR) utilizes advanced imaging technology to improve intra-operative visualization and facilitate efficient care in procedures that are relatively image dependent. The robotic C-arm provides improved 2D image quality and is capable of large volume three-dimensional fluoroscopy (3DF) that can rapidly create multiplanar CT like images. Here we discuss on the technique, utility, potential benefits, pitfalls, and complications of using the hybrid suite with and without intra-arterial balloon occlusion for pelvic and acetabular fracture surgery. We also present a case series of patient who underwent pelvic fixation using the HOR. While not advocated for routine use in all pelvic and acetabular fractures; the hybrid suite can be an effective tool in the treatment of complex cases and may facilitate efficient care of the hemodynamically unstable patient. It should be considered when resuscitative stabilization, angioembolization, intra-arterial balloon occlusion, or life-threatening bleeding is anticipated. Additionally, use of the hybrid room allows access to 3D fluoroscopy, and the associated benefits, if a mobile 3D unit is otherwise unavailable. These benefits must be weighed against the cumbersome table, the potential pitfalls with patient size and positioning, and the increased cost to the hospital.

Bone Morphogenetic Protein-2 Promotes Human Mesenchymal Stem Cell Survival and Resultant Bone Formation When Entrapped in Photocrosslinked Alginate Hydrogels.

There is a substantial need to prolong cell persistence and enhance functionality in situ to enhance cell-based tissue repair. Bone morphogenetic protein-2 (BMP-2) is often used at high concentrations for osteogenic differentiation of mesenchymal stem cells (MSCs) but can induce apoptosis. Biomaterials facilitate the delivery of lower doses of BMP-2, reducing side effects and localizing materials at target sites. Photocrosslinked alginate hydrogels (PAHs) can deliver osteogenic materials to irregular-sized bone defects, providing improved control over material degradation compared to ionically cross-linked hydrogels. It is hypothesized that the delivery of MSCs and BMP-2 from a PAH increases cell persistence by reducing apoptosis, while promoting osteogenic differentiation and enhancing bone formation compared to MSCs in PAHs without BMP-2. BMP-2 significantly decreases apoptosis and enhances survival of photoencapsulated MSCs, while simultaneously promoting osteogenic differentiation in vitro. Bioluminescence imaging reveals increased MSC survival when implanted in BMP-2 PAHs. Bone defects treated with MSCs in BMP-2 PAHs demonstrate 100% union as early as 8 weeks and significantly higher bone volumes at 12 weeks, while defects with MSC-entrapped PAHs alone do not fully bridge. This study demonstrates that transplantation of MSCs with BMP-2 in PAHs achieves robust bone healing, providing a promising platform for bone repair.