Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography.

Vordemvenne T, Wähnert D, Koettnitz J, et al. Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography. Cells. 2020;9(3): 654.Scaffold materials for bone regeneration are crucial for supporting endogenous healing after accidents, infections, or tumor resection. Although beneficial impacts of microtopological or nanotopological cues in scaffold topography are commonly acknowledged, less consideration is given to the interplay between the microscale and nanoscale. Here, micropores with a 60.66 ± 24.48 m diameter ordered by closely packed collagen fibers are identified in pre-wetted Spongostan, a clinically-approved collagen sponge. On a nanoscale level, a corrugated surface of the collagen sponge is observable, leading to the presence of 32.97 ± 1.41 nm pores. This distinct micro- and nanotopography is shown to be solely sufficient for guiding osteogenic differentiation of human stem cells in vitro. Transplantation of Spongostan into a critical-size calvarial rat bone defect further leads to fast regeneration of the lesion. However, masking the micro- and nanotopographical cues using SiO2 nanoparticles prevents bone regeneration in vivo. Therefore, we demonstrate that the identified micropores allow migration of stem cells, which are further driven towards osteogenic differentiation by scaffold nanotopography. The present findings emphasize the necessity of considering both micro- and nanotopographical cues to guide intramembranous ossification, and might provide an optimal cell- and growth-factor-free scaffold for bone regeneration in clinical settings

Same-gender differences in perioperative complications and transfusion management for lower limb arthroplasty

Abstract Introduction Total hip (THA) and knee arthroplasty (TKA) are surgical interventions for patients with primary and posttraumatic osteoarthritis. The present clinical investigation compared gender differences in THA and TKA. Methods Data from 419 patients following primary THA and TKA were collected. The occurrence of systemic and surgery-related complications, the units of blood transfused, and the change in Hb were investigated. Hb was collected preoperatively and at 1, 2, 4 and 7 days postoperatively. Statistical analysis was performed using the software IBM SPSS 28. Results There was no significant difference in surgery-related and general complications in men between THA and TKA. A significant difference between THA and TKA in systemic complications in women was observed. No significant difference between THA and TKA in related to surgery-related complications was evidenced. In men, no difference in Hb progression was observed. In women, a significant Hb drop was evidenced (p = 0.03). The rate of blood transfusion units in women was significantly greater in TKA than in THA (p = 0.001). No statistically significant difference was observed in men in the rate of transfusion between THA and TKA. Conclusion Perioperative care should be organized differently for women and men. Furthermore, a differentiation between the procedures for each sex could prevent the occurrence of perioperative complicated courses

Pharmacological agents for bone fracture healing: talking points from recent clinical trials

IntroductionPharmacological strategies might influence bone healing in terms of time to union or quality of mature bone. This expert opinion discussed the current level I evidence on the experimental pharmacological agents used to favor bone fracture healing.Areas coveredThis study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the 2020 PRISMA statement. In April 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, Embase. All the randomized clinical trials investigating pharmacological agents for bone fracture healing were accessed. No time constraint was set for the search. The search was restricted to RCTs. No additional filters were used in the database search. Data from 19 RCTs (4067 patients) were collected. 78% (3160 of 4067) were women. The mean length of the follow-up was 9.3 months (range, 1–26 months). The mean age of the patients was 64.4 years (range, 8–84 years).Expert opinionCalcitonin could favor bone fracture healing. Bisphosphonates (alendronate, zoledronate, clodronate), monoclonal antibodies (denosumab, romosozumab), statins, vitamin D and calcium supplementation, strontium ranelate, and ibuprofen did not influence bony healing. Concerning the effect of parathormone, current level I evidence is controversial, and additional studies are required.Level of evidenceLevel I, systematic review of RCTs

Spongostan™ Leads to Increased Regeneration of a Rat Calvarial Critical Size Defect Compared to NanoBone® and Actifuse

Wähnert D, Koettnitz J, Merten M, et al. Spongostan™ Leads to Increased Regeneration of a Rat Calvarial Critical Size Defect Compared to NanoBone® and Actifuse. Materials. 2021;14(8): 1961.Bone substitute materials are becoming increasingly important in oral and maxillofacial surgery. Reconstruction of critical size bone defects is still challenging for surgeons. Here, we compared the clinically applied organic bone substitute materials NanoBone® (nanocrystalline hydroxyapatite and nanostructured silica gel; n = 5) and Actifuse (calcium phosphate with silicate substitution; n = 5) with natural collagen-based Spongostan™ (hardened pork gelatin containing formalin and lauryl alcohol; n = 5) in bilateral rat critical-size defects (5 mm diameter). On topological level, NanoBone is known to harbour nanopores of about 20 nm diameter, while Actifuse comprises micropores of 200–500 µm. Spongostan™, which is clinically applied as a haemostatic agent, combines in its wet form both nano- and microporous topological features by comprising 60.66 ± 24.48 μm micropores accompanied by nanopores of 32.97 ± 1.41 nm diameter. Micro-computed tomography (µCT) used for evaluation 30 days after surgery revealed a significant increase in bone volume by all three bone substitute materials in comparison to the untreated controls. Clearly visual was the closure of trepanation in all treated groups, but granular appearance of NanoBone® and Actifuse with less closure at the margins of the burr holes. In contrast, transplantion of Spongostan™ lead to complete filling of the burr hole with the highest bone volume of 7.98 ccm and the highest bone mineral density compared to all other groups. In summary, transplantation of Spongostan™ resulted in increased regeneration of a rat calvarial critical size defect compared to NanoBone and Actifuse, suggesting the distinct nano- and microtopography of wet Spongostan™ to account for this superior regenerative capacity. Since Spongostan™ is a clinically approved product used primarily for haemostasis, it may represent an interesting alternative in the reconstruction of defects in the maxillary region

Same-gender differences in perioperative complications and transfusion management for lower limb arthroplasty

$\bf Introduction$ Total hip (THA) and knee arthroplasty (TKA) are surgical interventions for patients with primary and posttraumatic osteoarthritis. The present clinical investigation compared gender differences in THA and TKA. $\bf Methods$ Data from 419 patients following primary THA and TKA were collected. The occurrence of systemic and surgery-related complications, the units of blood transfused, and the change in Hb were investigated. Hb was collected preoperatively and at 1, 2, 4 and 7 days postoperatively. Statistical analysis was performed using the software IBM SPSS 28. $\bf Results$ There was no significant difference in surgery-related and general complications in men between THA and TKA. A significant difference between THA and TKA in systemic complications in women was observed. No significant difference between THA and TKA in related to surgery-related complications was evidenced. In men, no difference in Hb progression was observed. In women, a significant Hb drop was evidenced ($\it p$ = 0.03). The rate of blood transfusion units in women was significantly greater in TKA than in THA ($\it p$ = 0.001). No statistically significant difference was observed in men in the rate of transfusion between THA and TKA. $\bf Conclusion$ Perioperative care should be organized differently for women and men. Furthermore, a differentiation between the procedures for each sex could prevent the occurrence of perioperative complicated courses