Pittsburgh Air Pollution Changes During the COVID-19 Lockdown.

The rapid spread of COVID-19 resulted in various public lockdowns across the globe. Previous studies showed that resultant travel restrictions improved air quality. The novel results presented here focus on source-specific changes and compare air quality for multiple years controlled for precipitation. This study sought to analyze air pollution changes in Pittsburgh, a city where an industrial past and present has led to elevated levels of particulate matter with representative diameter of ≤ 2.5µm (PM2.5). Data from the Allegheny County Health Department, from monitors located near a variety of site types, were analyzed with generalized linear models that used a gamma distribution with a log link to determine the magnitude and significance of changes in air pollution during the COVID-19 lockdown. The hypothesis was that nitrogen dioxide (NO2), which is primarily linked to vehicular traffic, would decrease significantly while potential decreases in particulate matter (PM2.5 and PM10) would be less apparent. Results of the regression models showed that NO2 was significantly reduced during lockdown at both monitoring sites and that PM10 was also significantly reduced at the majority of monitoring sites. However, decreases in PM2.5 pollution were only observed at half of the monitoring locations, and the location which observed the greatest decreases is located adjacent to an industrial source. Decreases in PM2.5 at this monitoring site were likely a result of reduced industrial processes both dependent and independent of the COVID-19 lockdown. This study suggests that industrial sources are a larger contributor of particulate matter than vehicular transportation in the city of Pittsburgh and that future air pollution reduction efforts should focus attention on emission reduction at these industrial facilities.

Impact of Low-Cost Point-of-Use Water Treatment Technologies on Enteric Infections and Growth among Children in Limpopo, South Africa.

Enteric infections early in life have been associated with poor linear growth among children in low-resource settings. Point-of-use water treatment technologies provide effective and low-cost solutions to reduce exposure to enteropathogens from drinking water, but it is unknown whether the use of these technologies translates to improvements in child growth. We conducted a community-based randomized controlled trial of two water treatment technologies to estimate their effects on child growth in Limpopo, South Africa. We randomized 404 households with a child younger than 3 years to receive a silver-impregnated ceramic water filter, a silver-impregnated ceramic tablet, a safe-storage water container alone, or no intervention, and these households were followed up quarterly for 2 years. We estimated the effects of the interventions on linear and ponderal growth, enteric infections assessed by quantitative molecular diagnostics, and diarrhea prevalence. The silver-impregnated ceramic water filters and tablets consistently achieved approximately 1.2 and 3 log reductions, respectively, in total coliform bacteria in drinking water samples. However, the filters and tablets were not associated with differences in height (height-for-age z-score differences compared with no intervention: 0.06, 95% CI: -0.29, 0.40, and 0.00, 95% CI: -0.35, 0.35, respectively). There were also no effects of the interventions on weight, diarrhea prevalence, or enteric infections. Despite their effectiveness in treating drinking water, the use of the silver-impregnated ceramic water filters and tablets did not reduce enteric infections or improve child growth. More transformative water, sanitation, and hygiene interventions that better prevent enteric infections are likely needed to improve long-term child growth outcomes.

Understanding and Perception of Overlapping Surgery in an Orthopaedic Trauma Population: A Survey Study.

INTRODUCTION: Recently, overlapping surgery has received attention on the national scale. This study quantifies orthopaedic trauma patients' familiarity and concern with overlapping surgery as it relates to their care. METHODS: A 15-question survey was voluntarily completed by 200 orthopaedic trauma patients in the outpatient setting of a level I trauma center. Three domains were evaluated in the survey: demographic data, familiarity with overlapping surgery, and the degree of concern with overlapping surgery. Patients read a position statement explaining the practice of overlapping surgery, and their changes in level of concern were evaluated. Descriptive statistics were used to evaluate the data. RESULTS: A total of 200 patients completed the survey, of which 98 (49%) were male. The age range was broadly distributed. After surgery, 124 patients (62%) were seen for follow up. The remaining 76 patients (38%) did not undergo surgery. Regarding the practice of overlapping surgery, 116 respondents (58%) had no knowledge. There were 127 patients (63%) who reported their concern level as a 1 on an ordinal scale from 1 to 5, corresponding to the lowest possible level. Overall, 182 patients (91%) reported a level of concern of 3 (the median) or less with an average score of 1.7, indicating a low average level of concern. Six patients (3%) reported the maximum level of concern. On the whole, 160 patients (80%) reported either a decreased level of concern or no change after reading our department's position statement on overlapping surgery. Of the 124 patients, 81 (65%) postoperatively reported that they perceived no effect by overlapping surgery. The most common factors cited as areas of concern by patients were the absence of attending physician in the operating room (26%), risk of error by the resident (34%), and risk of a missed step in the surgical procedure (31%). CONCLUSION: These data indicate that most respondents had no previous knowledge of overlapping surgery and had a generally low level of concern with its use as practiced at our institution. Disclosing the use of overlapping surgery and its purpose to patients is an important component of preoperative counseling. LEVEL OF EVIDENCE: Level V.

Challenges to Sustainable Safe Drinking Water: A Case Study of Water Quality and Use across Seasons in Rural Communities in Limpopo Province, South Africa.

Consumption of microbial-contaminated water can result in diarrheal illnesses and enteropathy with the heaviest impact upon children below the age of five. We aimed to provide a comprehensive analysis of water quality in a low-resource setting in Limpopo province, South Africa. Surveys were conducted in 405 households in rural communities of Limpopo province to determine their water-use practices, perceptions of water quality, and household water-treatment methods. Drinking water samples were tested from households for microbiological contamination. Water from potential natural sources were tested for physicochemical and microbiological quality in the dry and wet seasons. Most households had their primary water source piped into their yard or used an intermittent public tap. Approximately one third of caregivers perceived that they could get sick from drinking water. All natural water sources tested positive for fecal contamination at some point during each season. The treated municipal supply never tested positive for fecal contamination; however, the treated system does not reach all residents in the valley; furthermore, frequent shutdowns of the treatment systems and intermittent distribution make the treated water unreliable. The increased water quantity in the wet season correlates with increased treated water from municipal taps and a decrease in the average contaminant levels in household water. This research suggests that wet season increases in water quantity result in more treated water in the region and that is reflected in residents' water-use practices.

Computer-assisted surgery: The use of stored intraoperative images for accurate restoration of femoral length and rotational alignment after fracture.

Most femoral fractures are now managed with minimally invasive internal fixation. In the absence of formal exposure of the fracture lines, these procedures make heavy use of C-arm fluoroscopy to allow both fracture reduction and placement of implants, at the expense of measurable radiation exposure to both patient and surgeon. Although this technology has been commercially available for over a decade, it has not yet been widely accepted by the Orthopaedic community.

Screw placement for acetabular fractures: which navigation modality (2-dimensional vs. 3-dimensional) should be used? An experimental study.

OBJECTIVES: Screw navigation techniques with different image guidance [2-dimensional (2D) vs. 3-dimensional (3D) fluoroscopy] were evaluated for acetabular fracture surgery. METHODS: Two-dimensional and 3D navigation images were analyzed for visualization of different osseous corridors: supra-acetabular, anterior column, posterior column, and infra-acetabular. Forty guide wires per group were placed in synthetic pelvis with a prefabricated soft tissue envelope (10 per group) using a 2D or 3D fluoroscopic navigation procedure. Duration of the single steps for each procedure and of cumulative fluoroscopy time was measured. The accuracy of guide wire placement was evaluated visually and in 3D cone-beam scans. RESULTS: The overall procedure time per pelvis was significantly reduced in the 3D group compared with the 2D group [mean ± standard error (SE) (minutes): 50.11 ± 1.38 vs. 63.42 ± 2.32; P < 0.0001]. A trend to reduction in image acquisition time [mean ± SE (minutes): 12.37 ± 1.34 vs. 15.43 ± 1.03; P = not significant] and significant increase in the cumulative fluoroscopy time [mean ± SE (seconds): 64 ± 9 vs. 13 ± 1.3; P < 0.0001) was measured in the 3D compared with the 2D group, caused by the 3D scan. Intra-articular misplacements were not observed in both the groups, but an increased accuracy could be achieved using the 3D image-based navigation procedure (perfect placement: 37 vs. 29; secure placement: 2 vs. 7; misplacement: 1 vs. 4). CONCLUSIONS: Both navigation procedures securely prevent an intra-articular penetration during drilling, but the 3D image-based navigation procedure increases the overall accuracy compared with the 2D image-based navigation technique (misplacement rates of 2.5% vs. 10%). Especially, in very narrow corridors (as the infra-acetabular screw path), the use of 3D navigation should be preferred.

Fluoro-Free navigated retrograde drilling of osteochondral lesions.

PURPOSE: Retrograde drilling of osteochondral lesions (OCLs) is a recommended, but demanding operative approach for revascularization of lesions in stage 1-3 according to Berndt and Harty after failed conservative treatment. The gold standard of intraoperative driller guidance is fluoroscopic control. Limitations are a 2D visualization of a 3D procedure and sometimes limited view of the OCL in fluoroscopy, leading to increased radiation exposure. A new image-free navigation procedure was evaluated for practicability and precision in first clinical applications. METHODS: In a period of 7 months, retrograde drillings were performed in eight patients (3x femoral condyle, 5x talus) using the new Fluoro-Free navigation procedure without rigidly fixed reference bases. RESULTS: In total, 29 retrograde drillings were performed without any technical problem. The overall mean operating time was 82.1 ± 29.3 min (34.6 ± 6.4 min for the standard arthroscopy and 11.2 ± 1.2 min per drill). Twenty-seven of 29 drillings hit the target with a 100% first-pass accuracy. Two complications during drilling (one navigation specific and one navigation independent) were observed. CONCLUSION: The paper describes the promising first clinical applications of a new Fluoro-Free navigation procedure for the retrograde drilling of OCLs determined by arthroscopy. The benefit of that navigated drillings with a high rate of first-pass accuracy and no need for radiation exposure in contrast to standard techniques is highlighted.

Navigated long-bone fracture reduction.

The first computer-assisted orthopaedic trauma procedures were limited to navigated drill-guide applications, in which the computer was used to predict the trajectory of the drill guide relative to stored radiographic images. By 2003, software for fracture reduction was commercially available. The ability to perform a minimally invasive fracture reduction with the aid of stored images, combined with navigated insertion of internal fixation, has long been considered the highest achievement in image-guided fracture surgery. It is now possible to apply computer-assisted techniques to all fractures that have traditionally been treated with the aid of intraoperative fluoroscopic control. Less-invasive fixation of long-bone fractures is often complicated by malrotation or shortening of the injured extremity, sometimes requiring reoperation. Recent developments in computer-assisted surgery now allow the orthopaedic surgeon to precisely match the anatomy of the injured extremity to that of the uninjured limb with respect to length and rotational alignment. This is particularly important in comminuted fractures, for which there are no anatomic clues to guide accurate reduction, and in the correction of malreduced fractures. Although computer-assisted technology is now readily available, it has not yet found widespread acceptance in the orthopaedic trauma community. New software workflows (i.e., the step-by-step progression through various screens in the software program during a computer-guided procedure) specific to individual procedures and implants may hasten adoption of these techniques.

A comparison of optical and electromagnetic computer-assisted navigation systems for fluoroscopic targeting.

OBJECTIVES: Freehand targeting using fluoroscopic guidance is routine for placement of interlocking screws associated with intramedullary nailing and for insertion of screws for reconstruction of pelvic and acetabular injuries. New technologies that use fluoroscopy with the assistance of computer guidance have the potential to improve accuracy and reduce radiation exposure to patient and surgeon. We sought to compare 2 fluoroscopic navigation tracking technologies, optical and electromagnetic versus standard freehand fluoroscopic targeting in a standardized model. INTERVENTION: Three experienced orthopaedic trauma surgeons placed 3.2-mm guide pins through test foam blocks that simulate cancellous bone. The entry site for each pin was within a circular (18-mm) entry zone. On the opposite surface of the test block (130-mm across), the target was a 1-mm-diameter radioopaque spherical ball marker. Each surgeon placed 10 pins using freehand targeting (control group) navigation using Medtronic iON StealthStation (Optical A), navigation using BrainLAB VectorVision (Optical B), or navigation using GE Medical Systems InstaTrak 3500 system (EM). OUTCOME MEASUREMENTS: Data were collected for accuracy (the distance from the exit site of the guidewire to the target spherical ball marker), fluoroscopy time (seconds), and total number of individual fluoroscopy images taken. RESULTS: The 2 optical systems and the electromagnetic system provided significantly improved accuracy compared to freehand technique. The average distance from the target was significantly (3.5 times) greater for controls (7.1 mm) than for each of the navigated systems (Optical A = 2.1 mm, Optical B = 1.9 mm EM = 2.4 mm; P < .05). Accuracy was similar for the 3 navigated systems, (P > 0.05). The ability to place guidewires in a 5-mm safe zone surrounding the target sphere was also significantly improved with the optical systems and the EM system (99% of wires in the safe zone) compared to controls (47% in the safe zone) (P < 0.002). Safe zone placement was similar among the 3 navigated systems (P > 0.05). Fluoroscopy time (seconds) and number of fluoroscopy images were similar among the three navigated groups (P > 0.05). Each of these parameters was significantly less when using the computer-guided systems than for freehand-unguided insertion (P < 0.01). CONCLUSIONS: Both optical and electromagnetic computer-assisted guidance systems have the potential to improve accuracy and reduce radiation use for freehand fluoroscopic targeting in orthopaedic surgery.

Supra-acetabular placement of external fixator pins: a safe and expedient method of providing the injured pelvis with stability.

Applying a stable anterior pelvic external fixator frame is a skill that should be mastered by all orthopedic surgeons who treat acutely injured patients. Splinting of an unstable pelvis during resuscitation can help to reduce the volume of the true pelvis, pending definitive surgical stabilization of the pelvic ring. Supra-acetabular pin placement, less familiar to most surgeons than iliac wing pin placement is, can provide a more reliable pin-bone interface and thus allow improved reduction ability with fewer soft-tissue complications. Because of their location, supra-acetabular pins also seem to be better tolerated than iliac crest pins when used for definitive management of the pelvic ring disruption. A young man who sustained a type II anteroposterior compression injury in a motor vehicle accident presented with symphyseal disruption (7 cm wide) and left anterior sacroiliac joint disruption. During resuscitation, the pelvis was anatomically reduced and stabilized with a supra-acetabular pin-based external fixator. Pin locations, chosen using palpable and cutaneous landmarks, were inserted without additional imaging guidance. The fracture was reduced anatomically, and the frame was used for definitive management of the pelvic ring injury.

Traumatic hemipelvectomy: case report and literature review.

Traumatic hemipelvectomy is a rare but devastating injury involving complete disruption of the hemipelvis from the pubic symphysis to the sacroiliac joints and often results in death. We present an interesting case of traumatic hemipelvectomy caused by a previously undescribed mechanism of injury in which judicious angiography and aggressive surgical treatment contributed to patient survival.

Image guidance: fluoroscopic navigation.

Computer-assisted orthopaedic surgery slowly is making its way into routine orthopaedic practice. Orthopaedic trauma has long been identified as a potential impact area of this new technology. Early experience with three-dimensional (3D) image-guided surgery was promising, but this particular technique was limited by the inability to update the 3D computer model in the operating room after fracture reduction maneuvers or implant placement. Virtual fluoroscopy, or fluoroscopic navigation, became available in 1999 and has proven to be a more versatile technology for fracture treatment. Fluoroscopic navigation systems allow the surgeon to store multiple intraoperative fluoroscopic images on a computer workstation; the position of special optically-tracked surgical instruments or implants then may be virtually overlaid onto the stored images in multiple planes during implant placement. The ability to update images after fracture manipulation now has expanded the application of computer-assisted surgery to any procedures that traditionally have relied on intraoperative C-arm use. In selected applications, this technology has been shown to decrease operative time and intraoperative radiation exposure. The advantages of the new technique of fluoroscopic navigation and its current use in trauma applications will be discussed.

Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution.

OBJECTIVE: To examine the effects of oral creatine (Cr) monohydrate supplementation on muscle Cr concentration, body mass, and total body water (TBW), extracellular water (ECW), and intracellular water (ICW) volumes. DESIGN AND SETTING: After an overnight fast, urinary Cr and creatinine concentrations, muscle Cr concentration, body mass, TBW, ECW, and ICW were measured, and subjects were randomly assigned to either a Cr or a placebo (P) group. The Cr group ingested 25 g/d of Cr for 7 days (loading phase) and 5 g/d for the remaining 21 days (maintenance phase), whereas the P group ingested a sucrose P using the same protocol. All the measures were reassessed immediately after the loading and maintenance phases. SUBJECTS: Sixteen men (age = 22.8 +/- 3.01 years, height = 179.8 +/- 7.1 cm, body mass = 84.8 +/- 11.2 kg) and 16 women (age = 21.8 +/- 2.51 years, height = 163.4 +/- 5.9 cm, body mass = 63.6 +/- 14.0 kg) involved in resistance training volunteered to participate in this study. MEASUREMENTS: Muscle Cr concentration was determined from the vastus lateralis muscle using a percutaneous needle-biopsy technique. Total body water, ECW, and ICW volumes were assessed using deuterium oxide and sodium bromide dilution analyses. RESULTS: The Cr group experienced a significant increase in muscle Cr concentration, body mass, and TBW. The P group experienced a small but significant increase in TBW only. CONCLUSIONS: The Cr supplementation protocol was effective for increasing muscle Cr concentrations, body mass, and TBW; however, fluid distribution was not changed.

Closed reduction and percutaneous fixation of anterior column acetabular fractures.

OBJECTIVE: The current standard treatment of anterior column acetabular fractures includes formal open reduction with internal fixation (ORIF) through a variety of anterior approaches. These approaches have been associated with significant blood loss, infection, lengthy operative times, and neurovascular complications. It therefore seems reasonable to consider less invasive alternatives to conventional treatment methods. A technique for percutaneous reduction and fixation of a particular acetabular fracture pattern is presented. Execution of this technique has been facilitated by the use of image-guided surgical navigation. MATERIALS AND METHODS: A retrospective review was performed on 23 patients who had suffered an acute anterior column fracture of the acetabulum (OTA 62-A3.2, 62-A3.3, 62-B3.2, 62-B3.3) managed with closed reduction and internal fixation using large-bore cannulated screws over an 11-year period. An additional three patients treated during the study period underwent formal ORIF with plates and screws after failure of attempted closed reduction, and were not included in this analysis. Eight of the 23 patients had an associated posterior hemitransverse fracture that was also managed with minimally invasive fixation. A variety of surgical navigation techniques were used to allow accurate percutaneous screw placement: CT-guided percutaneous fixation was performed in 10 patients (1990-1995); fluoroscopy alone was used in four patients (1995-1998); and computer-assisted virtual fluoroscopy was used in nine patients (1999-2002). Some fractures were nondisplaced but potentially unstable, and involved the superior weight-bearing dome; others required closed manipulation using Schanz-pin joysticks placed into the iliac wings and held in place with a temporary external fixator. One patient required a limited open reduction followed by percutaneous screw fixation. After confirmation of adequate reduction, one to three large-bore cannulated screws were placed percutaneously using previously defined safe trajectories. All patients were managed postoperatively with early mobilization and physical therapy. RESULTS: The average preoperative and postoperative displacements were 8.9 and 2.4 mm, respectively. No patient had a loss of reduction during healing. As experience was gained with the computer-assisted imaging, total fluoroscopy times were as little as 6 s, and were routinely kept below 45 s. None of the patients experienced infection, significant blood loss, or iatrogenic neurologic or visceral injury. No symptomatic heterotopic ossification was noted. Of those patients available for follow-up at a minimum of 2 years, the average HSS self-administered hip score was 91. CONCLUSION: We believe that our findings substantiate percutaneous reduction and internal fixation of anterior column acetabular fractures as a safe and effective alternative to formal ORIF, with a low anticipated complication rate and excellent outcome.

Mechanisms and management of stress fractures in physically active persons.

OBJECTIVE: To describe the anatomy of bone and the physiology of bone remodeling as a basis for the proper management of stress fractures in physically active people. DATA SOURCES: We searched PubMed for the years 1965 through 2000 using the key words stress fracture, bone remodeling, epidemiology, and rehabilitation. DATA SYNTHESIS: Bone undergoes a normal remodeling process in physically active persons. Increased stress leads to an acceleration of this remodeling process, a subsequent weakening of bone, and a higher susceptibility to stress fracture. When a stress fracture is suspected, appropriate management of the injury should begin immediately. Effective management includes a cyclic process of activity and rest that is based on the remodeling process of bone. CONCLUSIONS/RECOMMENDATIONS: Bone continuously remodels itself to withstand the stresses involved with physical activity. Stress fractures occur as the result of increased remodeling and a subsequent weakening of the outer surface ofthe bone. Once a stress fracture is suspected, a cyclic management program that incorporates the physiology of bone remodeling should be initiated. The cyclic program should allow the physically active person to remove the source of the stress to the bone, maintain fitness, promote a safe return to activity, and permit the bone to heal properly.