Background: This study aimed to determine the difference between computer-assisted virtual surgical technology and 3-dimensional (3D) printing technology in preoperative planning for proximal humeral fractures. Methods: Between February 2009 and October 2015, 131 patients with 3 and 4-part proximal humeral fractures were divided into 3 groups on the basis of the preoperative planning method: conventional (n = 53), virtual surgical (n = 46), and 3D printing (n = 32). Fracture characteristics and intraoperative realization of preoperative planning (reduction shape and implant choices) were evaluated. Postoperative functional outcomes were assessed using the American Shoulder and Elbow Surgeons, Constant-Murley, and Short Form-36 (SF-36) scoring systems and shoulder range of motion; postoperative radiographic outcomes were assessed with respect to the loss of the neck-shaft angle (NSA) and loss of humeral head height (HHH). Results: Excellent sensitivity, specificity, and accuracy for fracture characteristics were seen in all 3 groups. The correlations for NSA (p = 0.033) and HHH (p = 0.035) were higher in the virtual surgical group than in the 3D printing group. The lengths of the medial support screws in the actual choices were shorter than those in the preoperative plan for the 3D printing group, but a similar pattern was not seen in the virtual surgical group. Compared with the conventional method, the virtual surgical and 3D printing methods of preoperative planning resulted in shorter operative time, less blood loss, and fewer fluoroscopic images. The functional outcomes in both the 3D printing and virtual surgical groups were better than those in the conventional group. The virtual surgical method was faster than the 3D printing method, as suggested by a shorter time to surgery (2.5 compared with 4.6 days; p < 0.001), a shorter time for preoperative planning (30.4 compared with 262.4 minutes; p < 0.001), and a decreased duration of hospital stay (10.9 compared with 14.6 days; p < 0.001). Conclusions: The clinical outcomes in both the virtual surgical and 3D printing groups were better than those in the conventional group. However, computer-assisted virtual surgical technology is more convenient and efficient, considering the shorter time for preoperative planning. In addition, it has improved correlation with preoperative planning. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Bone cements such as polymethyl methacrylate and calcium phosphates have been widely used for the reconstruction of bone. Despite their remarkable clinical success, the low degradation rate of these materials hampers a broader clinical use. Matching the degradation rate of the materials with neo bone formation remains a challenge for bone-repairing materials. Moreover, questions such as the mechanism of degradation and how the composition of the materials contribute to the degradation property remain unanswered. Therefore, the review provides an overview of currently used biodegradable bone cements such as calcium phosphates (CaP), calcium sulfates and organic-inorganic composites. The possible degradation mechanism and clinical performance of the biodegradable cements are summarized. This paper reviews up-to-date research and applications of biodegradable cements, hoping to provide researchers in the field with inspirations and references.

The design principle of osteogenic bone grafts has shifted from immunological inertness to limiting foreign body response to combined osteoimmunomodulatory activity to promote high-quality endogenous bone regeneration. Recently developed immunomodulatory mucin hydrogels have been shown to elicit very low complement activation and suppress macrophage release and activation after implantation in vivo. However, their immunoregulatory activity has not yet been studied in the context of tissue repair. Herein, we synthesized mucin-monetite composite materials and investigated their early osteoimmunomodulation using a critical-size rat bone defect model. We demonstrated that the composites can polarize macrophages towards the M2 phenotype at weeks 1 and 2. The early osteoimmunomodulation enhanced early osteogenesis and angiogenesis and ultimately promoted fracture healing and engraftment (revascularization of the host vasculature) at weeks 6 and 12. Overall, we demonstrated the applicability of mucin-based immunomodulatory biomaterials to enhance tissue repair in tissue engineering and regenerative medicine.

Calcium phosphate cement with enhanced washout resistance and mechanical properties has been developed by the in situ crosslinking of glycidyl methacrylate modified γ-polyglutamic acid within the cement matrix, forming an interpenetrating network.