Characterization of an artificial skull cap for cranio-maxillofacial surgery training

Three internal fixation methods for Danis-Weber-B distal fibular fractures: A biomechanical comparison in an osteoporotic fibula model

A common agreement for the surgical treatment of osteoporotic ankle fractures has not been defined yet although locking plates are preferred for fractures with poor bone quality. This study aims to evaluate the mechanical stability of locked and conventional plates on osteoporotic Danis-Weber-B-fibula fracture models. Fractured custom-made osteoporotic fibulae were treated with neutralization plate plus lag screw, locking plate plus lag screw, or a standalone locking plate. Load until failure was applied mimicking single-leg stance. Stiffness, failureload, and interfragmentary movements were investigated. Stiffness, failureload and axial fragment movement showed no significant differences among groups. Shear movements and fragment rotation around the shaft of the neutralization plate were on average twice as high as those of the locking plates. Although no superiority was shown for overall mechanical performance, the locking plate groups exhibited higher shear and rotational stability than the neutralization plate.

CREATION OF A LOW-COST ENDOSCOPIC FLAVECTOMY TRAINING MODEL

ABSTRACT Objective The objective of the study was the development of a low cost simulator of the endoscopic lumbar spine flavectomy technique for use as a teaching method in order to make endoscopic training more accessible. Methods The study was a descriptive research project conducted at the Orthopedic Skills Laboratory of the Health Sciences Department of the Federal University of Paraná. Easily accessible, low cost materials, such as a commercial-use mannequin, EVA plastic, PVC and copper tubing were used to develop the simulator.. Results At the end of the project, it was possible to build a simulator of the endoscopic lumbar spine flavectomy technique with a budget of approximately 464 BRL, or approximately 140 USD. Conclusions We concluded that it was possible to build an endoscopic lumbar spine flavectomy technique simulator on a budget of less than half a Brazilian minimum monthly wage, which makes training more accessible to academics, residents and surgeons. Level of Evidence V; Expert opinion.

Bone surrogates provide authentic onlay graft fixation torques

Onlay graft bone augmentation is a standard practice to restore the loss of height of the alveolar ridge following loss of a tooth. Cranial grafts, lifted from the parietal bone, are sandwiched and used to bridge the bony defect in the jaw by means of small screws. During the elevation of the covering gum and subsequent screw placement, care has to be taken in order to preserve underlying nerves. Therefore, to avoid harm to the patient, a solid education of surgeons is essential, which requires training and experience. A simulator for cranial graft-lift training was already developed and shall be expanded to train the augmentation of the lifted implants. Therefore, in this study, synthetic bones for onlay block graft screw placement with realistic haptics for the screw application training were evaluated and compared with human specimens. Six different polyurethane based bone surrogate composites, enriched with varying amounts of calcium-based mineral fillers and blowing agents, were developed. The haptical properties of these synthetic bones were validated for screw placement and compared with human parietal bone specimens. For that, bones were pre-drilled, screws were automatically inserted using a customized testbench and the slope of the screw-insertion torques were analyzed. The slope of the screw insertion torques of the human reference bones was 56.5 ± 14.0 * 10^-3 Nm/deg, Surrogates with lower amounts of mineral fillers and blowing agents showed lower torques than the human bone. Synthetic bones, validated for drilling, milling and sawing in an earlier study, also achieved significantly lower torques, which were only the half of the human parietal bones. Two intermediate stages of the aforementioned material compositions, consisting of 75% mineral filler with 0.75% blowing agent and 100% mineral filler with 1.00% blowing agent revealed results comparable with human bone (57.4 ± 10.2 *10^-3 Nm/deg, p = 0.893 and 54.9 ± 11.1 *10^-3 Nm/deg, p = 0.795, respectively). In conclusion, our findings suggest that, two newly developed polyurethane-based materials mimicking the haptical properties of an onlay bone graft screw fixation, have been identified. Thus, these surrogates are capable of mimicking real bone tissue in our simulator for the education of novice surgeons.