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Disuse osteopenia is a well‐recognized consequence of prolonged physical inactivity, but its rate after orthopaedic injuries necessitating non‐weight‐bearing is not well studied. The purpose of this study was to estimate the rate of disuse osteopenia at the lumbar spine and proximal femur in patients with lower extremity trauma admitted to the hospital. We performed a retrospective chart review of patients with lower extremity trauma with a period of strict non‐weight‐bearing between completion of two computed tomography (CT) scans. The radiodensity of the proximal femur or lumbar vertebrae was measured from the earliest and latest available CT scans within the non‐weight‐bearing timeframe. The change in estimated bone mineral density (eBMD) was calculated as a proxy for disuse osteopenia. A total of 189,111 patients were screened, with 17 patients in the proximal femur group and 15 patients in the lumbar spine group meeting inclusion and exclusion criteria. The average rate of change in eBMD of the proximal femur was a decrease of 7.54 HU/day, 95% confidence interval (CI) [3.65, 11.43]. The average rate of change in eBMD of the lumbar spine was an increase of 1.45 HU/day, 95% CI [−3.15, 6.06]. In admitted, non‐weight‐bearing orthopaedic trauma patients, our novel study suggests that the proximal femur experiences disuse osteopenia during periods of non‐weight‐bearing, although this finding was not observed at the lumbar spine. The clinical significance of this data underscores the important consideration of disuse osteopenia by all physicians when caring for patients that may require non‐weight‐bearing restrictions. [ABSTRACT FROM AUTHOR]

This study attempts to further our understanding of how expertise is acquired in a specific vocational context. Using unstructured interviews with both individuals and groups, carried out whilst engaged in practice, it examines what happens when dry stone wallers are developing their skills, how they gain expertise and how they communicate their learning. It was concluded that learning a craft such as dry stone walling is complex and individual. Learning was clearly contextualised and did not take place in linear stages. The use of maxims or 'rules of thumb' was a key element in the learning process, and the use of tacit knowledge and intuition were much in evidence as expertise developed. By questioning whether expertise can be achieved by following a set of rules, or that it progresses in a specific, set direction, the study also highlights the reflective and emotional aspects of becoming an 'expert' that are likely to be relevant to other vocational areas. [ABSTRACT FROM AUTHOR]

Minimally invasive glaucoma surgeries (MIGS) offer an effective way to lower intraocular pressure without inducing extensive trauma to the anterior segment. In order to predict their efficacy, an analytical model of the conventional aqueous humor outflow pathway is developed using a resistor network. The model describes outflow through the normal eye and allows for the effects of geometric changes in the outflow pathway as IOP changes. By selectively removing these resistors, the model can be used to examine and predict the outcomes of several surgical procedures currently used to treat glaucoma. Treatments examined include traditional trabeculectomy, several ab interno methods for trabeculotomy and trabeculectomy, as well as recently developed trabecular stents that bypass the trabecular meshwork and dilate Schlemm canal. The model's predictions for the efficacy of these procedures generally matched well with the efficacy determined in experimental studies, although it tended to somewhat overestimate the efficacy of these procedures. Matching the model to experimental data indicated that a partial trabeculotomy substantially increases flow to collector channels within that region and approximately 1.5 clock hours past the ends of the trabeculotomized region. Similarly, trabecular bypass stents substantially increase flow to collector channels up to 1.5 clock hours past the open ends of the stent. The resistor model we have developed can be used to predict the efficacy of a variety of MIGS procedures. Circumferential flow in Schlemm canal extends the efficacy of MIGS, but this effect is limited to a few clock hours. • Novel resistor network model developed for aqueous outflow system. • Partial trabeculotomy increases flow to collector channels near the surgery. • Trabecular bypass stents increase flow to collector channels near the surgery. [ABSTRACT FROM AUTHOR]

Purpose: Existing literature is discrepant on the differences in blood loss and need for transfusion between short and long cephalomedullary nails used for extracapsular geriatric hip fractures. However, prior studies used the inaccurate estimated rather than the more accurate 'calculated' blood loss based on hematocrit dilution (Gibon in IO 37:735–739, 2013, Mercuriali in CMRO 13:465–478, 1996). This study sought to clarify whether use of short nails is associated with clinically meaningful reductions in calculated blood loss and resultant need for transfusion. Methods: A retrospective cohort study using bivariate and propensity score-weighted linear regression analyses was conducted examining 1442 geriatric (ages 60–105) patients undergoing cephalomedullary fixation of extracapsular hip fractures over 10 years at two trauma centers. Implant dimensions, pre and postoperative laboratory values, preoperative medications, and comorbidities were recorded. Two groups were compared based on nail length (greater or less than 235 mm). Results: Short nails were associated with a 26% reduction in calculated blood loss (95% confidence interval: 17–35%; p < 10–14) and a 24-min (36%) reduction in mean operative time (95% confidence interval: 21–26 min; p < 10–71). The absolute reduction in transfusion risk was 21% (95% confidence interval: 16–26%; p < 10–13) yielding a number needed to treat of 4.8 (95% confidence interval: 3.9–6.4) with short nails to prevent one transfusion. No difference in reoperation, periprosthetic fracture, or mortality was noted between groups. Conclusion: Use of short compared to long cephalomedullary nails for geriatric extracapsular hip fractures confers reduced blood loss, need for transfusion, and operative time without a difference in complications. [ABSTRACT FROM AUTHOR]

Introduction: COVID-19 was declared a pandemic by the World Health Organization on the 11th of March 2020 with the NHS deferring all non-urgent activity from the 15th of April 2020. The aim of our study was to assess the impact of COVID-19 on Trauma and Orthopaedic trainees nationally.Methods: Trauma and Orthopaedic (T&O) specialty trainees nationally were asked to complete an electronic survey specifically on the impact of COVID-19 on their training. This UK based survey was conducted between May 2020 and July 2020.Results: A total of 185 out of 975 (19%) T&O specialty trainees completed the survey. Redeployment was experienced by 25% of trainees. 84% of respondents had experienced a fall in total operating numbers in comparison with the same time period in 2019. 89% experienced a fall in elective operating and 63% experienced a fall in trauma operating. The pandemic has also had an effect on the delivery of teaching, with face to face teaching being replaced by webinar-based teaching. 63% of training programmes delivered regular weekly teaching, whilst 19% provided infrequent sessions and 11% provided no teaching.Conclusion: This study has objectively demonstrated the significant impact of the COVID-19 pandemic on all aspects of T&O training. [ABSTRACT FROM AUTHOR]

Antibiotic loaded cement beads are commonly used for the treatment of biofilm related orthopaedic periprosthetic infections; however the effects of antibiotic loading and exposure of beads to body fluids on release kinetics are unclear. The purpose of this study was to determine the effects of (i) antibiotic loading density (ii) loading amount (iii) material type and (iv) exposure to body fluids (blood or synovial fluid) on release kinetics and efficacy of antibiotics against planktonic and lawn biofilm bacteria. Short-term release into an agar gel was evaluated using a fluorescent tracer (fluorescein) incorporated in the carrier materials calcium sulfate (CaSO 4 ) and poly methyl methacrylate (PMMA). Different fluorescein concentrations in CaSO 4 beads were evaluated. Mechanical properties of fluorescein-incorporated beads were analyzed. Efficacy of the antibiotics vancomycin (VAN) or tobramycin (TOB) alone and in combination was evaluated against lawn biofilms of bioluminescent strains of Staphylococcus aureus and Pseudomonas aeruginosa . Zones of inhibition of cultures (ZOI) were measured visually and using an in-vivo imaging system (IVIS). The influence of body fluids on release was assessed using CaSO 4 beads that contained fluorescein or antibiotics and were pre-coated with human blood or synovial fluid. The spread from the beads followed a square root of time relationship in all cases. The loading concentration had no influence on short-term fluorescein release and pre-coating of beads with body fluids did not affect short-term release or antibacterial activity. Compared to PMMA, CaSO 4 had a more rapid short term rate of elution and activity against planktonic and lawn biofilms. This study highlights the importance of considering antibiotic loading and packing density when investigating the clinical application of bone cements for infection management. [ABSTRACT FROM AUTHOR]

Background:Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) are the major causative agents of acute and chronic infections. Antibiotic-loaded calcium sulfate beads (ALCSB) are used in the management of musculoskeletal infections such as periprosthetic joint infections (PJI). Methods: To determine whether the number and spatial distribution of ALCSB are important factors to totally eradicate biofilms, ALCSBs containing vancomycin and tobramycin were placed on 24 h agar lawn biofilms as a single bead in the center, or as 16 beads placed as four clusters of four, a ring around the edge and as a group in the center or 19 beads evenly across the plate. Bioluminescence was used to assess spatial metabolic activity in real time. Replica plating was used to assess viability. Results: For both strains antibiotics released from the beads completely killed biofilm bacteria in a zone immediately adjacent to each bead. However, for PA extended incubation revealed the emergence of resistant colony phenotypes between the zone of eradication and the background lawn. The rate of biofilm clearing was greater when the beads were distributed evenly over the plate. Conclusions: Both number and distribution pattern of ALCSB are important to ensure adequate coverage of antibiotics required to eradicate biofilms. [ABSTRACT FROM AUTHOR]