This is the only cadaveric study of bridging vein rupture focused on short pulse durations, which are usually associated with falls. The data suggest a tolerance level of approximately 10,000 rad/second2 for pulse durations shorter than 10 msec, which seems to decrease for longer pulse durations.

Initial osteogenesis at the implant interface is, to a great extent, determined by the implant surface characteristics and the interfacial loading conditions. The present study investigated the effect of various degrees of relative movement on the tissue differentiation around a roughened screw-shaped immediately loaded implant. Repeated-sampling bone chambers were installed in the tibia of 10 rabbits. In each of the chambers, three experiments were performed by inducing 0 (control), 30, and 90 microm implant displacement for 9 wk. A linear mixed model and a logistic mixed model with alpha = 5% determined statistical significance. Tissue filling of the bone chamber was similar for the three test conditions. The bone area fraction was significantly higher for 90 microm implant displacement compared with no displacement. A significantly higher fraction of bone trabeculae was found for 30 and 90 microm implant displacement compared with the unloaded situation. The incidence of osteoid-to-implant and bone-to-implant contact was significantly higher for 90 microm implant displacement compared with 30 and 0 microm implant displacement. Significantly more osteoid in contact with the implant was found for the loaded conditions compared with no loading. Well-controlled micro-motion positively influenced bone formation at the interface of a roughened implant. An improved bone reaction was detected with increasing micro-motion.

Well-controlled immediate implant loading accelerates tissue mineralization at the interface. Adequate bone stimulation via mechanical coupling may account for the larger bone response around the screw-type implant compared with the cylindrical implant.

Immediate loading had a positive effect on the tissue differentiation and bone formation around cylindrical turned titanium implants. Controlled implant micro-motion up to 50 microm had a positive effect on the bone formation at its interface.

No abstract

A predominant effect of the interfacial mechanical environment over the implant surface characteristics on the differentiating cell population is suggested.

Bone regeneration is the process whereby bone is able to (scarlessly) repair itself from trauma, such as fractures or implant placement. Despite extensive experimental research, many of the mechanisms involved still remain to be elucidated. Over the last decade, many mathematical models have been established to investigate the regeneration process in silico. The first models considered only the influence of the mechanical environment as a regulator of the healing process. These models were followed by the development of bioregulatory models where mechanics was neglected and regeneration was regulated only by biological stimuli such as growth factors. The most recent mathematical models couple the influences of both biological and mechanical stimuli. Examples are given to illustrate the added value of mathematical regeneration research, specifically in the in silico design of treatment strategies for non-unions. Drawbacks of the current continuum-type models, together with possible solutions in extending the models towards other time and length scales are discussed. Finally, the demands for dedicated and more quantitative experimental research are presented.

The device maintains preoperative motion at the index and adjacent levels, seems to protect against acceleration of adjacent-level degeneration as seen after anterior cervical discectomy and fusion, and remains securely anchored in the adjacent bone mass in the long run. Heterotopic ossification was frequently seen. The vast majority of all patients had a good to excellent clinical outcome.