Cost-effectiveness and diagnostic accuracy of focused cardiac ultrasound in the pre-participation screening of athletes: the SPORT-FoCUS study.

AIMS: The role of pre-participation screening (PPS) modalities in preventing sudden cardiac death (SCD) in athletes is debated due to a high false-positive rate. Focused cardiac ultrasound (FoCUS) has shown higher sensitivity and specificity, but its cost-effectiveness remains uncertain. This study aimed to determine the diagnostic performance and cost-effectiveness of FoCUS use in PPS. METHODS AND RESULTS: A total of 2111 athletes (77.4% male, mean age 24.9 ± 15.2years) underwent standardized family and medical history collection, physical examination, resting electrocardiography (ECG), FoCUS (10 min/5 views protocol), comprehensive echocardiography and exercise stress test. We prospectively evaluated three PPS incremental models: Model A, standardized medical history and physical examination Model B, Model A plus resting and stress ECG and Model C, Model B plus FoCUS (10 min/5 views protocol). We determined their incremental diagnostic accuracy and cost-effectiveness ratio. A total of 30 athletes were diagnosed with a cardiac condition associated with SCD: 3 were identified by Model A, 14 by Model B, and 13 athletes by Model C. The introduction of FoCUS markedly increased the sensitivity of PPS, compared with Model A and Model B (sensitivity 94% vs. 19% vs. 58% specificity 93% vs. 93% vs. 92%). The total screening costs were as follows: Model A 35.64 euros, Model B 87.68 euros, and Model C 120.89 euros. Considering the sole conditions at risk of SCD, the incremental cost-effectiveness ratio was 135.62 euros for Model B and 114.31 for Model C. CONCLUSIONS: The implementation of FoCUS into the PPS allows to identify a significantly greater number of athletes at risk of SCD and markedly lowers the false negative rate. Furthermore, the incorporation of FoCUS into the screening process has shown to be cost-effective.

A significant electrocardiography false-positive rate makes pre-participation screening (PPS) for sudden cardiac death (SCD) in athletes controversial. Focused cardiac ultrasound (FoCUS) may increase sensitivity and specificity however, its cost-effectiveness is unknown. This study evaluates the diagnostic performance and cost-effectiveness of FoCUS in PPS. Incorporating a simplified echocardiographic exam called FoCUS into PPS resulted in higher diagnostic reliability, with a lower rate of false negatives and a higher number of athletes at risk for SCD identified.The integration of FoCUS into the screening process resulted to be cost-effective in our athletes' cohort.

COVID-19: Relative Risk of Non-Vaccinated to Vaccinated Individuals.

Following the outbreak of the COVID-19 pandemic, Italy has implemented an extensive vaccination campaign involving individuals above the age of 12, both sexes. The public opinion and the medical community alike questioned the usefulness and efficacy of the vaccines against SARS-CoV-2. The widespread opinion was that the vaccines protected individuals especially against serious conditions which could require intensive care and may lead to the death of the patient rather than against the possibility of infection. In order to quantify the effect of the vaccination campaign, we calculated the relative risks of non-vaccinated and vaccinated individuals for all possible outcomes of the disease: infection, hospitalization, admission to intensive care and death. Relative risk was assessed by means of likelihood ratios, the ratios of the probability of an outcome in non-vaccinated individuals to the probability of the same outcome in vaccinated individuals. Results support the hypothesis that vaccination has an extensive protective effect against both critical conditions and death. Nonetheless, the relative magnitude of the protection in vaccinated individuals compared to those non-vaccinated appears to be higher against the former outcome than the latter, for reasons which need to be investigated further.

Reconstructing Group Wavelet Transform From Feature Maps With a Reproducing Kernel Iteration.

In this article, we consider the problem of reconstructing an image that is downsampled in the space of its SE(2) wavelet transform, which is motivated by classical models of simple cell receptive fields and feature preference maps in the primary visual cortex. We prove that, whenever the problem is solvable, the reconstruction can be obtained by an elementary project and replace iterative scheme based on the reproducing kernel arising from the group structure, and show numerical results on real images.

How Artificial Intelligence and New Technologies Can Help the Management of the COVID-19 Pandemic.

The COVID-19 pandemic has worked as a catalyst, pushing governments, private companies, and healthcare facilities to design, develop, and adopt innovative solutions to control it, as is often the case when people are driven by necessity. After 18 months since the first case, it is time to think about the pros and cons of such technologies, including artificial intelligence-which is probably the most complex and misunderstood by non-specialists-in order to get the most out of them, and to suggest future improvements and proper adoption. The aim of this narrative review was to select the relevant papers that directly address the adoption of artificial intelligence and new technologies in the management of pandemics and communicable diseases such as SARS-CoV-2: environmental measures; acquisition and sharing of knowledge in the general population and among clinicians; development and management of drugs and vaccines; remote psychological support of patients; remote monitoring, diagnosis, and follow-up; and maximization and rationalization of human and material resources in the hospital environment.

Physical Activity during COVID-19 Lockdown in Italy: A Systematic Review.

The recent COVID-19 pandemic has imposed a general lockdown in Italy, one of the most affected countries at the beginning of the outbreak, between 9 March and 3 May 2020. As a consequence, Italian citizens were confined at home for almost two months, an unprecedented situation, which could have negative effects on both psychological and physical health. The aim of this study was to review the published papers concerning the effects of the lockdown on physical activity and the consequences on general health. As expected, most studies highlighted a significant reduction in the amount of performed physical activity compared to before lockdown, in both the general population and in individuals with chronic conditions. This fact had negative consequences on both general health, in terms of increased body mass, and on specific chronic conditions, especially obesity and neurological diseases.

Coupling between macrophage phenotype, angiogenesis and bone formation by calcium phosphates.

The ability of calcium phosphate (CaP) materials to induce bone formation varies with their physicochemical properties, with surface topography as one of the most crucial triggers. In view of the natural wound healing processes (e.g., inflammation, angiogenesis, tissue formation and remodeling) initiated after surgical implantation, we here comparatively investigated the biological cascades occurring upon ectopic implantation of a tricalcium phosphate with submicron surface topography (TCP-S, osteoinductive) and a tricalcium phosphate with micron-scale topography (TCP-B, non-osteoinductive). In vitro, TCP-S facilitated M2 polarization of macrophages derived from a human leukemic cell line (THP-1) as shown by the enhanced secretion of TGF-ß and CCL18. Interestingly, the conditioned media of polarized M2 macrophages on TCP-S enhanced tube formation by human umbilical vein endothelial cells (HUVECs), while had no influence on the osteogenic differentiation of human bone marrow stromal cells (HBMSCs). Following an intramuscular implantation in canines, TCP-S locally increased typical M2 macrophage markers (e.g., IL-10) at week 1 to 3 and enhanced blood vessel formation after week 3 as compared to TCP-B. Bone formation was observed histologically in TCP-S 6 weeks after implantation, and bone formation was inhibited when an angiogenesis inhibitor (KRN633) was loaded onto TCP-S. No bone formation was observed for TCP-B. The data presented herein suggest strong links between macrophage polarization, angiogenesis and CaP-induced bone formation. STATEMENT OF SIGNIFICANCE: The ability of calcium phosphate (CaP) materials to induce bone formation varies with their physicochemical properties, and the key physicochemical properties relevant to CaP-induced bone formation have been outlined in the last two decades. However, the biological mechanism underlying this material-driven osteoinduction remains largely unknown. This manuscript presented demonstrates strong links between surface topography, macrophage polarization, angiogenesis and bone formation in CaP materials implanted in non-osseous sites. The finding may provide new clues for further exploring the possible mechanism underlying osteoinduction by CaP materials.

Predicting Cardiovascular Risk in Athletes: Resampling Improves Classification Performance.

Cardiovascular diseases are the main cause of death worldwide. The aim of the present study is to verify the performances of a data mining methodology in the evaluation of cardiovascular risk in athletes, and whether the results may be used to support clinical decision making. Anthropometric (height and weight), demographic (age and sex) and biomedical (blood pressure and pulse rate) data of 26,002 athletes were collected in 2012 during routine sport medical examinations, which included electrocardiography at rest. Subjects were involved in competitive sport practice, for which medical clearance was needed. Outcomes were negative for the largest majority, as expected in an active population. Resampling was applied to balance positive/negative class ratio. A decision tree and logistic regression were used to classify individuals as either at risk or not. The receiver operating characteristic curve was used to assess classification performances. Data mining and resampling improved cardiovascular risk assessment in terms of increased area under the curve. The proposed methodology can be effectively applied to biomedical data in order to optimize clinical decision making, and-at the same time-minimize the amount of unnecessary examinations.

The role of calcium phosphate surface structure in osteogenesis and the mechanisms involved.

Calcium phosphate (CaP) ceramics have been widely used for bone regeneration because of their ability to induce osteogenesis. Surface properties, including chemical composition and surface structure, are known to play a crucial role in osteoconduction and osteoinduction. This review systematically analyzes the effects of surface properties, in particular the surface structure, of CaP scaffolds on cell behavior and new bone formation. We also summarize the possible signaling pathways involved in the osteogenic differentiation of bone-related cells when cultured on surfaces with various structures in vitro. The significant immune response initiated by surface structure involved in osteogenic differentiation of cells is also discussed in this review. Taken together, the new biological principle for advanced biomaterials is not only to directly stimulate osteogenic differentiation of bone-related cells but also to modulate the immune response in vivo. Although the reaction mechanism responsible for bone formation induced by CaP surface structure is not clear yet, the insights on surface structure-mediated osteogenic differentiation and osteoimmunomodulation could aid the optimization of CaP-based biomaterials for bone regeneration. STATEMENT OF SIGNIFICANCE: CaP ceramics have similar inorganic composition with natural bone, which have been widely used for bone tissue scaffolds. CaP themselves are not osteoinductive; however, osteoinductive properties could be introduced to CaP materials by surface engineering. This paper systematically summarizes the effects of surface properties, especially surface structure, of CaP scaffolds on bone formation. Additionally, increasing evidence has proved that the bone healing process is not only affected by the osteogenic differentiation of bone-related cells, but also relevant to the the cooperation of immune system. Thus, we further review the possible signaling pathways involved in the osteogenic differentiation and immune response of cells cultured on scaffold surface. These insights into surface structure-mediated osteogenic differentiation and osteoimmunomodulated-based strategy could aid the optimization of CaP-based biomaterials.

Performance prediction models based on anthropometric, genetic and psychological traits of Croatian sprinters.

Elite athletes differ from each other in their characteristics according to their discipline. This study aimed to identify performance predictors in elite Croatian sprinters taking into consideration their anthropometric, psychological and genetic characteristics. One hundred and four elite Croatian sprinters (68 males and 36 females) participated in this study. Of them, 38 are currently competing in the 100-metre dash. The others are former sprinters. The participants underwent direct anthropometric assessment. Participants were also tested by means of the Competitive State Anxiety Inventory-2 and for ACE and ACTN3 polymorphisms. Multiple linear regression analysis was applied to identify the best model for performance prediction. Different models were developed for males and females. Anthropometric traits accounted for 44% of the variance in performance for males, 62% for females. Once other traits (psychological for females) were entered into the model, no additional contribution to the variance was observed. The most significant predictors of higher running velocity were bicristal diameter and foot dimensions in males, and leg length and clean one-repetition maximum in females. The findings suggest that performance in sprinters is associated with anthropometric characteristics, with biomechanical implications that may be used to provide a more complete evaluation of sprinters' performance.

Efficacy of a synthetic calcium phosphate with submicron surface topography as autograft extender in lapine posterolateral spinal fusion.

Posterolateral spinal fusion (PLF) is a common procedure in orthopedic surgery that is performed to fuse adjacent vertebrae to reduce symptoms related to spinal conditions. In the current study, a novel synthetic calcium phosphate with submicron surface topography was evaluated as an autograft extender in a validated rabbit model of PLF. Fifty-nine skeletally mature New Zealand white rabbits were divided into three groups and underwent single-level intertransverse process PLF at L4-5 using (1) autologous bone graft (ABG) alone or in a 1:1 combination with (2) calcium phosphate granules (ABG/BCPgranules ), or (3) granules embedded in a fast-resorbing polymeric carrier (ABG/BCPputty ). After 6, 9, and 12 weeks, animals were sacrificed and spinal fusion was assessed by manual palpation, Radiographs, micro-CT, mechanical testing (12 weeks only), histology, and histomorphometry. Based on all endpoints, all groups showed a gradual progression in bone formation and maturation during time, leading to solid fusion masses between the transverse processes after 12 weeks. Fusion assessments by manual palpation, radiography and histology were consistent and demonstrated equivalent fusion rates between groups, with high bilateral fusion rates after 12 weeks. Mechanical tests after 12 weeks indicated substantially lower range of motion for all groups, compared to non-operated controls. By histology and histomorphometry, the gradual formation and maturation of bone in the fusion mass was confirmed for each graft type. With these results, we describe the equivalent performance between autograft and a novel calcium phosphate material as an autograft extender in a rabbit model of PLF using an extensive range of evaluation techniques. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2080-2090, 2019.

Modulating Bone Regeneration in Rabbit Condyle Defects with Three Surface-Structured Tricalcium Phosphate Ceramics.

Tricalcium phosphate (TCP) ceramics are used as bone void fillers because of their bioactivity and resorbability, while their performance in bone regeneration and material resorption vary with their physical properties (e.g., the dimension of the crystal grain). Herein, three TCP ceramic bone substitutes (TCP-S, TCP-M, and TCP-L) with gradient crystal grain size (0.77 ± 0.21 µm for TCP-S, 1.21 ± 0.35 µm for TCP-M and 4.87 ± 1.90 µm for TCP-L), were evaluated in a well-established rabbit lateral condylar defect model (validated with sham) with respect to bone formation and material resorption up to 26 weeks. Surface structure-dependent bone regeneration was clearly shown after 4 weeks implantation with TCP-S having most mineralized bone (20.2 ± 3.4%), followed by TCP-M (14.0 ± 3.5%), sham (8.1 ± 4.2%), and TCP-L (6.6 ± 2.6%). Afterward, the amount of mineralized bone was similar in all the three groups, but bone marrow and material resorption varied. After 26 weeks, TCP-S induced most bone tissue formation (mineralized bone + bone marrow) (61.6 ± 7.8%) and underwent most material resorption (80.1 ± 9.0%), followed by TCP-M (42.9 ± 5.2% and 61.4 ± 8.0% respectively), TCP-L (28.3 ± 5.5% and 45.6 ± 9.7% respectively), and sham (25.7 ± 4.2%). Given the fact that the three ceramics are chemically identical, the results indicate that the surface structure (especially, the crystal grain size) of TCP ceramics can greatly tune their bone regeneration potential and the material resorption in rabbit condyle defect model, with the submicron surface structured TCP ceramic performing the best.

Meeting Report: Growth and Social Environment. Proceedings of the 25th Aschauer Soiree, held at Krobielowice, Poland, November 18th 2017.

Twenty-two scientists met at Krobielowice, Poland, to discuss the impact of the social environment, spatial proximity, migration, poverty, but also psychological factors such as body perception and satisfaction, and social stressors such as elite sports, and teenage pregnancies, on child and adolescent growth. The data analysis included linear mixed effects models with different random effects, Monte Carlo analyses, and network simulations. The work stressed the importance of the peer group, but also included historic material, some considerations about body proportions, and growth in chronic liver, and congenital heart disease.

Biphasic calcium phosphate with submicron surface topography in an Ovine model of instrumented posterolateral spinal fusion.

As spinal fusions require large volumes of bone graft, different bone graft substitutes are being investigated as alternatives. A subclass of calcium phosphate materials with submicron surface topography has been shown to be a highly effective bone graft substitute. In this work, a commercially available biphasic calcium phosphate (BCP) with submicron surface topography (MagnetOs; Kuros Biosciences BV) was evaluated in an Ovine model of instrumented posterolateral fusion. The material was implanted stand-alone, either as granules (BCPgranules) or as granules embedded within a fast-resorbing polymeric carrier (BCPputty) and compared to autograft bone (AG). Twenty-five adult, female Merino sheep underwent posterolateral fusion at L2-3 and L4-5 levels with instrumentation. After 6, 12, and 26 weeks, outcomes were evaluated by manual palpation, range of motion (ROM) testing, micro-computed tomography, histology and histomorphometry. Fusion assessment by manual palpation 12 weeks after implantation revealed 100% fusion rates in all treatment groups. The three treatment groups showed a significant decrease in lateral bending at the fusion levels at 12 weeks (P < 0.05) and 26 weeks (P < 0.001) compared to the 6 week time-point. Flexion-extension and axial rotation were also reduced over time, but statistical significance was only reached in flexion-extension for AG and BCPputty between the 6 and 26 week time-points (P < 0.05). No significant differences in ROM were observed between the treatment groups at any of the time-points investigated. Histological assessment at 12 weeks showed fusion rates of 75%, 92%, and 83% for AG, BCPgranules and BCPputty, respectively. The fusion rates were further increased 26 weeks postimplantation. Similar trends of bone growth were observed by histomorphometry. The fusion mass consisted of at least 55% bone for all treatment groups 26 weeks after implantation. These results suggest that this BCP with submicron surface topography, in granules or putty form, is a promising alternative to autograft for spinal fusion.

Variation of the bone forming ability with the physicochemical properties of calcium phosphate bone substitutes.

Because of their bioactive properties and chemical similarity to the inorganic component of bone, calcium phosphate (CaP) materials are widely used for bone regeneration. Six commercially available CaP bone substitutes (Bio-Oss, Actifuse, Bi-Ostetic, MBCP, Vitoss and chronOs) as well as two tricalcium phosphate (TCP) ceramics with either a micron-scale (TCP-B) or submicron-scale (TCP-S) surface structure are characterized and their bone forming potential is evaluated in a canine ectopic implantation model. After 12 weeks of implantation in the paraspinal muscle of four beagles, sporadic bone (0.1 ± 0.1%) is observed in two Actifuse implants (2/4), limited bone (2.1 ± 1.4%) in four MBCP implants (4/4) and abundant bone (21.6 ± 4.5%) is formed in all TCP-S implants (4/4). Bone is not observed in any of the Bio-Oss, Bi-Ostetic, Vitoss, chronOs and TCP-B implants (0/4). When correlating the bone forming potential with the physicochemical properties of each material, we observe that the physical characteristics (e.g. grain size and micropore size at the submicron scale) might be the dominant trigger of material directed bone formation via specific mechanotransduction, instead of protein adsorption, surface mineralization and calcium ion release.

Topography of calcium phosphate ceramics regulates primary cilia length and TGF receptor recruitment associated with osteogenesis.

The surface topography of synthetic biomaterials is known to play a role in material-driven osteogenesis. Recent studies show that TGFß signalling also initiates osteogenic differentiation. TGFß signalling requires the recruitment of TGFß receptors (TGFßR) to the primary cilia. In this study, we hypothesize that the surface topography of calcium phosphate ceramics regulates stem cell morphology, primary cilia structure and TGFßR recruitment to the cilium associated with osteogenic differentiation. We developed a 2D system using two types of tricalcium phosphate (TCP) ceramic discs with identical chemistry. One sample had a surface topography at micron-scale (TCP-B, with a bigger surface structure dimension) whilst the other had a surface topography at submicron scale (TCP-S, with a smaller surface structure dimension). In the absence of osteogenic differentiation factors, human bone marrow stromal cells (hBMSCs) were more spread on TCP-S than on TCP-B with alterations in actin organization and increased primary cilia prevalence and length. The cilia elongation on TCP-S was similar to that observed on glass in the presence of osteogenic media and was followed by recruitment of transforming growth factor-ß RII (p-TGFß RII) to the cilia axoneme. This was associated with enhanced osteogenic differentiation of hBMSCs on TCP-S, as shown by alkaline phosphatase activity and gene expression for key osteogenic markers in the absence of additional osteogenic growth factors. Similarly, in vivo after a 12-week intramuscular implantation in dogs, TCP-S induced bone formation while TCP-B did not. It is most likely that the surface topography of calcium phosphate ceramics regulates primary cilia length and ciliary recruitment of p-TGFß RII associated with osteogenesis and bone formation. This bioengineering control of osteogenesis via primary cilia modulation may represent a new type of biomaterial-based ciliotherapy for orthopedic, dental and maxillofacial surgery applications. STATEMENT OF SIGNIFICANCE: The surface topography of synthetic biomaterials plays important roles in material-driven osteogenesis. The data presented herein have shown that the surface topography of calcium phosphate ceramics regulates mesenchymal stromal cells (e.g., human bone marrow mesenchymal stromal cells, hBMSCs) with respect to morphology, primary cilia structure and TGFßR recruitment to the cilium associated with osteogenic differentiation in vitro. Together with bone formation in vivo, our results suggested a new type of biomaterial-based ciliotherapy for orthopedic, dental and maxillofacial surgery by the bioengineering control of osteogenesis via primary cilia modulation.

Cells responding to surface structure of calcium phosphate ceramics for bone regeneration.

Surface structure largely affects the inductive bone-forming potential of calcium phosphate (CaP) ceramics in ectopic sites and bone regeneration in critical-sized bone defects. Surface-dependent osteogenic differentiation of bone marrow stromal cells (BMSCs) partially explained the improved bone-forming ability of submicron surface structured CaP ceramics. In this study, we investigated the possible influence of surface structure on different bone-related cells, which may potentially participate in the process of improved bone formation in CaP ceramics. Besides BMSCs, the response of human brain vascular pericytes (HBVP), C2C12 (osteogenic inducible cells), MC3T3-E1 (osteogenic precursors), SV-HFO (pre-osteoblasts), MG63 (osteoblasts) and SAOS-2 (mature osteoblasts) to the surface structure was evaluated in terms of cell proliferation, osteogenic differentiation and gene expression. The cells were cultured on tricalcium phosphate (TCP) ceramics with either micron-scaled surface structure (TCP-B) or submicron-scaled surface structure (TCP-S) for up to 14 days, followed by DNA, alkaline phosphatase (ALP) and quantitative polymerase chain reaction gene assays. HBVP were not sensitive to surface structure with respect to cell proliferation and osteogenic differentiation, but had downregulated angiogenesis-related gene expression (i.e. vascular endothelial growth factor) on TCP-S. Without additional osteogenic inducing factors, submicron-scaled surface structure enhanced ALP activity and osteocalcin gene expression of human (h)BMSCs and C2C12 cells, favoured the proliferation of MC3T3-E1, MG63 and SAOS-2, and increased ALP activity of MC3T3-E1 and SV-HFO. The results herein indicate that cells with osteogenic potency (either osteogenic inducible cells or osteogenic cells) could be sensitive to surface structure and responded to osteoinductive submicron-structured CaP ceramics in cell proliferation, ALP production or osteogenic gene expression, which favour bone regeneration. Copyright © 2017 John Wiley & Sons, Ltd.

Body composition and size in sprint athletes.

BACKGROUND: The aims of the present study were to assess competitive sprinters' body size and composition and to determine their impact on performance. METHODS: Ninety-eight competitive male sprinters (100 m) participated in this cross-sectional study. A series of measurements was directly taken and data on muscular strength and power tests were self-reported. Body composition was assessed by skinfold method and somatotype was calculated by the Heath-Carter anthropometric method. Sprinters were classified into three groups depending on their personal best time and comparisons were performed between the athletes in the top and in the bottom tertiles. Relationships between anthropometric traits and performance were assessed by Pearson's correlation coefficients. RESULTS: Top sprinters had significantly greater body mass index, relaxed and contracted upper arm girths, thigh and calf girths, fat free mass and fat free mass index, and lower ectomorphy than the lowest tertile. Strength and power were significantly higher. Personal best time was significantly correlated with several anthropometric traits and indices of lean body mass. CONCLUSIONS: Body size, composition and somatotype differ between performance levels in speed running. Being less ectomorphic, with a greater fat free mass and strength, can explain significant differences in sprinting performances. The results presented in this study provide a point of reference about sprinter characteristics, which can help coaches and sport scientists to improve sprinter performance.

* Comparison of Two Moldable Calcium Phosphate-Based Bone Graft Materials in a Noninstrumented Canine Interspinous Implantation Model.

There is a continuing search for novel synthetic materials as an alternative to autologous bone grafting. Different technologies are explored to promote bone formation, which include the addition of BioGlass™ particles in calcium phosphate (CaP)-based materials and the use of surface modification in the form of submicron surface topographies. In this work, we aimed at comparing the bone formation in a noninstrumented canine interspinous model of moldable formulations of a submicron-surface structured tricalcium phosphate/alkylene oxide copolymer (CaP/AOC) or a tricalcium phosphate/BioGlass/collagen (CaP/BG/C) bone graft material. Intramuscular implantation was carried out as well to evaluate soft tissue responses. Eight mature male mongrel dogs underwent single-level, noninstrumented interspinous implantation, where the bone graft materials were implanted at either side of the spinous processes (L3-L4), with separation by the interspinous ligament ensuring comparison of both materials in each animal (n = 8 per material). The materials were also implanted in paraspinal muscle pouches. Animals were euthanized 12 weeks after surgery and the lumbar spines excised and intramuscular implants retrieved. Undecalcified sections were prepared for histological evaluation and histomorphometry was performed to quantify bone formation and material resorption. After 12 weeks, all submicron structured CaP/AOC implants showed abundant bone formation in the (L3-L4) interspinous space (20.8% ± 6.8%), whereas bone was not found in the CaP/BG/C implants (0% ± 0%). Intramuscularly, the CaP/AOC material triggered significant bone formation (12.0% ± 7.8%), whereas CaP/BG/C did not form any bone. In both the spinal and muscular sites, resorption of the CaP/AOC material was evident by a decrease in Feret diameter of the CaP granules as well as in their histological surface compared with the starting material, whereas CaP/BG/C material had a milder resorption. This study shows that a submicron-surface structured CaP/AOC bone graft material has superior bone-forming properties in both an interspinous implantation model and intramuscularly, as compared with a CaP/BG/C bone graft material.

Submicron-surface structured tricalcium phosphate ceramic enhances the bone regeneration in canine spine environment.

Calcium phosphate ceramics with submicron-scaled surface structure can trigger bone formation in non-osseous sites and are expected to enhance bone formation in spine environment. In this study, two tricalcium phosphate ceramics having either a submicron-scaled surface structure (TCP-S) or a micron-scaled one (TCP-B) were prepared and characterized regarding their physicochemical properties. Granules (size 1-2 mm) of both materials were implanted on either left or right side of spinous process, between the two lumbar vertebrae (L3-L4), and in paraspinal muscle of eight beagles. After 12 weeks of implantation, ectopic bone was observed in muscle in TCP-S explants (7.7 ± 3.7%), confirming their ability to inductively form bone in non-osseous sites. In contrast, TCP-B implants did not lead to bone formation in muscle. Abundant bone (34.1 ± 6.6%) was formed within TCP-S implants beside the two spinous processes, while limited bone (5.1 ± 4.5%) was seen in TCP-B. Furthermore, the material resorption of TCP-S was more pronounced than that of TCP-B in both the muscle and spine environments. The results herein indicate that the submicron-scaled surface structured tricalcium phosphate ceramic could enhance bone regeneration as compared to the micron-scaled one in spine environment. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1865-1873, 2016.