RESUMEN
BACKGROUND: The Terrible Triad of the elbow is a constellation of elbow dislocation, radial head fracture and coronoid process fracture. A common type of coronoid fracture documented with this triad is type II Regan-Morrey coronoid fractures. The preferred fixation method for this fracture type is the lasso technique, medial-lateral tunnel orientation being the traditional approach. Considering elbow anatomy, we saw an opportunity to potentially improve fixation by altering the suture lasso tunnel orientation to a proximal-distal orientation. HYPOTHESIS: Two tunnels in the proximal-distal direction would result in greater biomechanical stability as compared to the traditional lasso technique. MATERIAL AND METHODS: A type 2 Regan-Morrey fracture was created in 12 fresh frozen cadaveric elbows at 50% of the coronoid height using an oscillating saw. The humero-ulnar joint was placed in 0 degrees flexion then loaded at a rate of 10mm/min to failure. RESULTS: The control technique (medio-lateral tunnels) showed failure load of 150±81N that was not significantly different (p=0.825) than the 134±116N measured for the modified technique (distal-proximal tunnels). The portion of the load-displacement curve used to calculate stiffness was linear (R^2=0.94±0.04) with determination coefficients that did not differ between the two groups (p=0.351). For stiffness, we measured 17±13N/mm and 14±12N/mm respectively for control and modified techniques that did not result in a significant difference (p=0.674). CONCLUSION: In this attempt to improve the shortcomings of the lasso technique, we found that changing from medio-lateral to proximal-distal drilling directions did not result in an appreciable biomechanical benefit. LEVEL OF EVIDENCE: Basic science study; Biomechanics.
RESUMEN
The adaptation of agriculture to climate change depends on the ability to integrate irrigation practices into water management applications. This requires robust water use estimates and the evaluation of management practices as a tool to conserve water. We combine a landscape level agricultural management model that accounts for risk and uncertainty through climate change with an aquifer model. The modelling system produces estimates of the long run aquifer abundance for management scenarios for a study area in the Lower Mississippi River Basin, United States. Except in the driest climate outcome, the aquifer abundance rises over time. We find that the increase in the aquifer for most climate outcomes occurs through judicious crop choice and aquifer recharge followed by a use of on-farm reservoirs later in the study period. Our modelling points to the greatest sensitivity of the long run aquifer abundance to fluctuations in crop prices and production costs followed by the cost of surface water for aquifer recharge.
