In vivo osseointegration of a randomized trabecular titanium structure obtained by an additive manufacturing technique.

The additive manufacturing techniques (AM) are able to realize three-dimensional trabecular structures that mimic the trabecular structure of the bone. An in vivo study in sheep was carried out with the aim of assessing the bone response and the trend of osteointegration of a randomized trabecular titanium structure produced by the AM technique. In 6 sheep were implanted 84 specimens with a trabecular titanium structure (4 implants in the femur distal epiphysis; 4 implants in the tibial plate; 6 implants in the tibial shaft). Sheep were sacrificed at 3 postoperative time-points: 6 weeks, 10 weeks, 14 weeks. Histomorphometric analysis was performed for the evaluation of Bone Implant Contact, and Bone Ingrowth. A standard push-out test was used to analyze the mechanical characteristics of the bone-implant interface. The histomorphometric data and biomechanical tests showed a fast osseointegration of the specimens both in the cancellous and in the cortical bone. The quantitative analysis of osseointegration data in cancellous bone showed the percentage of the surface of the implant in direct contact with the regenerated bone matrix significantly improved from 28% at 6 weeks to 54% at 14 weeks. An early osseointegration occurred in cortical bone showing that 75% of surface of implant was in direct contact with regenerated bone after 6 weeks; this value increased to 85% after 14 weeks. Mechanical tests revealed an early improvement of mean peak load of implants at 10 weeks (4486 N ± 528 N) compared to values at 6 weeks (2516 N ± 910 N) confirming the high rate of progression of osseointegration in the cortical bone. The non-mineralized matrix followed an increasing process of mineralization almost completely after 14 weeks. The results of this study have showed a rapid osseointegration and excellent biocompatibility for a randomized trabecular titanium structure that should be confirmed by clinical investigations.

Balanced propofol sedation administered by nonanesthesiologists: The first Italian experience.

AIM: To assess the efficacy and safety of a balanced approach using midazolam in combination with propofol, administered by non-anesthesiologists, in a large series of diagnostic colonoscopies. METHODS: Consecutive patients undergoing diagnostic colonoscopy were sedated with a single dose of midazolam (0.05 mg/kg) and low-dose propofol (starter bolus of 0.5 mg/kg and repeated boluses of 10 to 20 mg). Induction time and deepest level of sedation, adverse and serious adverse events, as well as recovery times, were prospectively assessed. Cecal intubation and adenoma detection rates were also collected. RESULTS: Overall, 1593 eligible patients were included. The median dose of propofol administered was 70 mg (range: 40-120 mg), and the median dose of midazolam was 2.3 mg (range: 2-4 mg). Median induction time of sedation was 3 min (range: 1-4 min), and median recovery time was 23 min (range: 10-40 min). A moderate level of sedation was achieved in 1561 (98%) patients, whilst a deep sedation occurred in 32 (2%) cases. Transient oxygen desaturation requiring further oxygen supplementation occurred in 8 (0.46%; 95% CI: 0.2%-0.8%) patients. No serious adverse event was observed. Cecal intubation and adenoma detection rates were 93.5% and 23.4% (27.8% for male and 18.5% for female, subjects), respectively. CONCLUSION: A balanced sedation protocol provided a minimalization of the dose of propofol needed to target a moderate sedation for colonoscopy, resulting in a high safety profile for non-anesthesiologist propofol sedation.

The neuroanatomical plates of Guido da Vigevano.

Guido da Vigevano was an Italian physician and engineer who lived in the 13th and 14th centuries. He was the first scientist who used pictures to illustrate his anatomical descriptions, developing for the first time a close relationship between anatomical studies and artistic drawings. This was further developed in the Renaissance. In his textbook Anathomia are displayed six plates showing for the first time neuroanatomical structures and techniques: dissection of the head by means of trephination, and depictions of the meninges, cerebrum, and spinal cord. On the surface of the brain painting it is possible to recognize a vague patterning of cortical convolutions. Ventricles are also described and shown. This book constituted the first attempt in the history of neuroscience to illustrate an anatomical description with schematic pictures to achieve a better understanding of such complex structures.