In the setting of ankle fractures with syndesmosis disruption, fixing the fibula in as much as 30 degrees of external rotation may go undetected using intraoperative fluoroscopy alone.
This study evaluated the feasibility of using a 'self-calibrating' display (EIZO CG277) to perform screenbased threshold perimetry. Such displays incorporate their own integrated photometer, so could potentially be used 'straight out of the box', without the need for time-consuming and costly luminance calibration by skilled experts. Concerns remain, however, due to the fact that the internal calibration of such devices is imperfect (i.e., is limited to a single screen location only) and due to lingering doubts regarding the accuracy of screen-based perimetry in general. To evaluate such a system, automated static threshold perimetry was performed in thirty-two normal-sighted adults. In one condition, participants performed a novel screen-based perimetry test, for which the screen was extensively calibrated using traditional photometric techniques/equipment. In a second condition, the same test was performed, but the display was calibrated using only the screen's integrated photometer (and assuming uniformity across the display). For reference, participants also completed a traditional visual-field assessment using a Humphrey Field Analyzer (HFA). All three tests were performed twice to assess test-retest repeatability (six tests total). The results showed no differences when comparing screen-based perimetric measurements made with internal self-calibration vs full manual calibration (either in terms of mean sensitivity, pointwise sensitivity, test-retest repeatability, or test duration). Furthermore, the accuracy and precision of both were indistinguishable from the current gold standard (HFA), although the HFA was approximately two minutes (~30%) faster. These results indicate that self-calibrating commercial monitors can be used to perform screen-based perimetry almost as well as current clinical devices, and without the need for any specialized knowledge or equipment to setup or maintain. This could facilitate perimetric testing in currently hard-to-reach settings, such as community centers, stroke wards, homes, rural locations, or developing countries.
The bone mineral density (BMD) in a given fracture site may affect the outcome of fracture fixation. Low BMD values, such as those occurring in osteoporotic bone, can determine the fixation method and the postoperative care. Evaluation of the BMD is either done subjectively during surgery or by a preoperative measurement. The technique most commonly used to measure BMD preoperatively is dual-energy X-ray absorptiometry (DEXA). DEXA scans have been shown to be site specific [1,2] and therefore may be inaccurate in determining local BMD at the fixation site. Furthermore, in trauma cases, patients frequently do not present with a pre-operative DEXA scan; and the ideal method of assessment would be intraoperative. Intraoperative BMD assessment could be used to guide surgical decisions such as the point of entry of a screw for a fracture plating system or use of locking versus non-locking screw-plate contruct.
The distal radius is a common site of fracture with volar plates and screws as the current clinical practice for fracture fixation [1]. Local measurements of bone quality at the sites of screw insertion aid in providing the most stable fixation with the least amount of hardware, minimizing the risk of construct failure and irritation to soft tissue [2, 3]. The clinical standard for pre-operative bone mineral density (BMD) assessment uses dual x-ray absorptiometry (DEXA). However, DEXA scans provide global BMD values and cannot accurately predict variations in BMD within a given anatomical site [4]. Furthermore, patients frequently present without a pre-operative DEXA scan, so intra-operative assessment would be ideal. We developed a simple sensor system that would be appropriate for assessing local BMD intra-operatively. The system consists of a “smart” Weber clamp instrumented with a single uniaxial strain gage that provides real-time feedback regarding the local BMD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.