Effects of wearing a cloth face mask on performance, physiological and perceptual responses during a graded treadmill running exercise test.

OBJECTIVES: To (1) determine if wearing a cloth face mask significantly affected exercise performance and associated physiological responses, and (2) describe perceptual measures of effort and participants' experiences while wearing a face mask during a maximal treadmill test. METHODS: Randomised controlled trial of healthy adults aged 18-29 years. Participants completed two (with and without a cloth face mask) maximal cardiopulmonary exercise tests (CPETs) on a treadmill following the Bruce protocol. Blood pressure, heart rate, oxygen saturation, exertion and shortness of breath were measured. Descriptive data and physical activity history were collected pretrial; perceptions of wearing face masks and experiential data were gathered immediately following the masked trial. RESULTS: The final sample included 31 adults (age=23.2±3.1 years; 14 women/17 men). Data indicated that wearing a cloth face mask led to a significant reduction in exercise time (-01:39±01:19 min/sec, p<0.001), maximal oxygen consumption (VO2max) (-818±552 mL/min, p<0.001), minute ventilation (-45.2±20.3 L/min), maximal heart rate (-8.4±17.0 beats per minute, p<0.01) and increased dyspnoea (1.7±2.9, p<0.001). Our data also suggest that differences in SpO2 and rating of perceived exertion existed between the different stages of the CPET as participant's exercise intensity increased. No significant differences were found between conditions after the 7-minute recovery period. CONCLUSION: Cloth face masks led to a 14% reduction in exercise time and 29% decrease in VO2max, attributed to perceived discomfort associated with mask-wearing. Compared with no mask, participants reported feeling increasingly short of breath and claustrophobic at higher exercise intensities while wearing a cloth face mask. Coaches, trainers and athletes should consider modifying the frequency, intensity, time and type of exercise when wearing a cloth face mask.

Recombinant human bone morphogenetic protein-2 use in the off-label treatment of nonunions and acute fractures: a retrospective review.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (BMP-2) is Food and Drug Administration-approved for use in acute open tibial shaft fractures. Some surgeons, however, also use BMP-2 in an "off-label" application for other acute fractures and for nonunion care. This retrospective study was performed to assess radiographic outcomes of off-label uses of BMP-2 for acute fractures and nonunions at our institution. METHODS: All eligible off-label BMP-2 applications between 2004 and 2008 for acute fractures or nonunions were reviewed. Univariate and multivariate analyses were completed to identify patient and clinical factors that could predict radiographic success or failure of the procedure. RESULTS: One hundred sixteen of 145 BMP-2 applications in 104 of 128 patients met inclusion and exclusion criteria. The overall radiographic union rate was 66% (76 of 116). In the univariate analysis, five factors correlated with significantly higher union rate: volume of bone defect <4 cm3, >2 cortices in contact at the index procedure, male gender, body mass index <30, and history of closed fracture pattern. Within the multivariate analysis, factors independently predictive of radiographic union included open versus closed fracture, gender, and volume of bone defect. CONCLUSION: Off-label use of BMP-2 in acute fractures and nonunions resulted in a 66% success rate. It remains uncertain whether there is any clinical advantage to this approach, but it appears that female gender, open injury, and higher volumes of bone defect may be important negative prognostic factors for obtaining radiographic union. Appropriately powered prospective randomized trials are needed for further clarification, especially in light of the high cost of this treatment.

A retrospective review of high-energy femoral neck-shaft fractures.

OBJECTIVES: To determine the incidence of femoral neck fractures with high-energy shaft fractures and to determine whether there was a correlation of neck fractures with antegrade or retrograde intramedullary nailing. We also evaluated the timing of diagnosis and the treatment options and outcomes. DESIGN AND SETTING: A retrospective review of patients with femoral shaft fractures treated at 8 level 1 trauma centers from 2001 to 2005. Two thousand eight hundred ninety-seven fractures were identified, and 89 patients had 91 femoral neck-shaft combinations (3.2%). PATIENTS: Average age: 36 years (15-72 years) and average Injury Severity Score: 18 (9-66). Seventy-eight patients had associated injuries; 67 of 91 femoral neck fractures were discovered before nailing. RESULTS: There were 24 missed femoral neck fractures, 11 discovered intraoperatively and 13 postoperatively. Of these 24 patients, 15 had retrograde fixation and 9 had antegrade femoral shaft fixation. There was a high rate of open femur fractures (34%) and an increased incidence of associated injuries (88%) with neck-shaft combinations. In 12 of 67 patients with a preoperative computed tomography scan, the scan did not demonstrate a femoral neck fracture. CONCLUSIONS: This study found a similar rate of neck-shaft combinations (3.2%), a higher rate of open fractures, and increased incidence of associated injuries compared with the literature. Most importantly, our data indicate that even with a negative preoperative computed tomography scan, a femoral neck fracture can be present. A trend also indicated more missed femoral neck fractures with retrograde nailing, which may be attributed to less fluoroscopic imaging of the hip with this technique. Patients with femoral shaft fractures should have good quality radiographs after femoral nailing to minimize the risk of missed femoral neck fractures.