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Fault zones are an important control on fluid flow, affecting groundwater supply, contaminant migration, and carbon storage. However, most models of fault seal do not consider fault zone cementation, despite the recognition that it is common and can dramatically reduce permeability. In order to study the field‐scale hydrogeologic effects of fault zone cementation, we conducted a series of aquifer pumping tests in wells installed within tens of meters of the variably cemented Loma Blanca Fault, a normal fault in the Rio Grande Rift. In the southern half of the study area, the fault zone is cemented by calcite; the cemented zone is 2‐8 m wide. In the center of the study area, the cemented fault zone is truncated at a buttress unconformity that laterally separates hydrostratigraphic units with a ∼40X difference in permeability. The fault zone north of the unconformity is not cemented. Constant rate pumping tests indicate that where the fault is cemented, it is a barrier to groundwater flow. This is an important demonstration that a fault with no clay in its core and similar sediment on both sides can be a barrier to groundwater flow by virtue of its cementation; most conceptual models for the hydrogeology of faults would predict that it would not be a barrier to groundwater flow. Additionally, the lateral permeability heterogeneity across the unconformity imposes another important control on the local flow field. This permeability discontinuity acts as either a no‐flow boundary or a constant head boundary, depending on the location of pumping. [ABSTRACT FROM AUTHOR]

Abstract: An understanding of the spatial and hydraulic properties of fast preferential flow pathways in the subsurface is necessary in applications ranging from contaminant fate and transport modeling to design of energy extraction systems. One method for the characterization of fracture properties over interwellbore scales is Multiperiod Oscillatory Hydraulic (MOH) testing, in which the aquifer response to oscillatory pressure stimulations is observed. MOH tests were conducted on isolated intervals of wells in siliciclastic and carbonate aquifers in southern Wisconsin. The goal was to characterize the spatial properties of discrete fractures over interwellbore scales. MOH tests were conducted on two discrete fractured intervals intersecting two boreholes at one field site, and a nest of three piezometers at another field site. Fracture diffusivity estimates were obtained using analytical solutions that relate diffusivity to observed phase lag and amplitude decay. In addition, MOH tests were used to investigate the spatial extent of flow using different conceptual models of fracture geometry. Results indicated that fracture geometry at both field sites can be approximated by permeable two‐dimensional fracture planes, oriented near‐horizontally at one site, and near‐vertically at the other. The technique used on MOH field data to characterize fracture geometry shows promise in revealing fracture network characteristics important to groundwater flow and transport. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to determine the predictive value of the clenched fist stress views in identifying scapholunate ligament injuries., Methods: An institutional review board-approved retrospective chart review was conducted of adult patients who underwent diagnostic arthroscopy with a ligamentous wrist injury from 2015 to 2020. Standard posteroanterior, lateral, and clenched fist stress radiographs were reviewed and scapholunate ligament gaps recorded., Results: A total of 124 patients were included, of which 88 had normal standard radiographs and clenched fist radiographs. The positive predictive value of the clenched fist view was 69%, whereas the negative predictive value was 58%. The sensitivity of the clenched fist view was 40%, while the specificity was 82%. Of those patients with a negative clenched fist view, 42% were found to have an arthroscopic Geissler classification of 3 or higher scapholunate ligament injury., Conclusions: Despite the emphasis on stress radiographic views, a normal stress clenched fist view does not preclude arthroscopic findings of a Geissler class 3 or greater injury in symptomatic patients. The sensitivity of a clenched fist view is only 40%. These findings question the utility of stress radiographs when assessing for scapholunate ligament injuries., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Level of Evidence: IV., (Copyright © 2021 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Orthopaedic Surgeons.)

This investigation assessed 106 consecutive primary proximal interphalangeal joint arthroplasties performed on border digits: 73 index or 33 little fingers. This was compared with 193 arthroplasties performed in non-border digits: 121 middle or 72 ring fingers. There were 20 proximal interphalangeal joint arthroplasties in the border digits that required revision surgery for pain and stiffness (10 digits), dislocation (six digits), implant fracture (one digit), and infection (three digits). Risk of revision surgery was not associated with border digit. The 5-year implant survival rate for the border digits was 81%. There was no significant difference in implant revision rate or joint dislocations between border and non-border digits. We conclude that proximal interphalangeal joint arthroplasties performed in border digits had similar pain relief, survivorship, complications, and reoperation rates compared with those performed in non-border digits. Level of evidence: IV.