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Abstract: The use of antibiotic-impregnated polymethylmethacrylate in joint arthroplasty is widespread. The Food and Drug Administration has approved commercially prepared antibiotic bone cement, but in a climate of increasingly drug-resistant bacteria, orthopedic surgeons often hand-mix their own. A recent study reported the effects on drug elution of different mixing methods designed to decrease antibiotic particle size and distribute those particles more uniformly. Theoretically, these mixing techniques could also improve antibiotic cement strength; however, the actual effects of these techniques on cement strength are undefined. In the present study, 3 different methods of mixing vancomycin with bone cement were compared. We conclude that the addition of vancomycin to polymethylmethacrylate at commonly accepted concentrations does substantially decrease cement strength and that more complex mixing techniques do not improve cement strength significantly. [Copyright &y& Elsevier]

A distal femoral extension osteotomy with patellar tendon advancement (DFEO+PTA) is a common treatment for individuals with cerebral palsy (CP) who walk in crouch. Musculoskeletal modeling suggests that the typical patella baja position post-DFEO+PTA may limit one's abilities to perform sit-to-stand (STS) tasks; however, STS function has not been assessed. Our purpose was to compare how well individuals who received a DFEO+PTA can perform a 5-times STS test (FTSST) eight or more years after surgery compared to their peers who did not receive a DFEO+PTA (non-DFEO+PTA group). Twenty-one participants completed the task (12 DFEO+PTA, 9 non-DFEO+PTA). Three-dimensional kinematics and kinetics were captured. Kinetics were non-dimensionalized to facilitate group comparisons. Non-DFEO+PTA participants performed the FTSST moderately faster than the DFEO+PTA group (median(IQR), 14.6(9.3) seconds vs. 20.3(10.1) seconds, non-parametric effect size ɣ=0.97, p=0.241). Peak negative knee power was larger for the non-DFEO+PTA group (Mean±SD, -0.063±0.025 vs. -0.048± 0.020, Cohen's d=0.66, p=0.165). A similar but weaker trend was observed for negative hip power (median(IQR) -0.120(0.066) vs. -0.105(0.044), ɣ=0.43, p=0.671). Both groups used their hips approximately twice as much as their knees to perform the task. The functional deficit among DFEO+PTA participants may be due to patella baja decreasing the knee extensor moment arm, which concurs with the modeling prediction. The group differences may also be due to the non-DFEO+PTA group being slightly higher functioning. Future research is warranted to determine if optimizing patella position during a DFEO+PTA may improve unaided STS function without compromising gait improvements. [ABSTRACT FROM AUTHOR]

Background Pelvic injuries in young children are rare, and it has been difficult to establish clinical guidelines to assist providers in managing blunt pelvic trauma, especially in non-Level 1 trauma centers. Objective Our aim was to describe the relationship among clinical findings, mechanism of injury, and the radiographic resources utilized in children with pelvic fractures presenting to a non-Level 1 trauma center. Methods A retrospective review of patients with a pelvic fracture treated in two urban pediatric Level 3 emergency departments was performed. Results Between 2001 and 2010, a total of 208 patients were identified. Avulsion/iliac wing fractures were the most common fractures (58.7%), and sports-related injuries were the most common mechanism of injury (50.0%). Children with sports-related injuries were more likely to sustain an avulsion fracture (p < 0.001), less likely to have a computed tomography scan obtained in the emergency department (p < 0.001), and less likely to have an associated injury (p < 0.001) than other children. Children struck by a motor vehicle (p < 0.001) or involved in a motor vehicle accident (p < 0.001) were more likely to receive a computed tomography scan (p < 0.001) and have associated head and extremity injuries (p < 0.001). Mechanism of injury was associated with abnormal computed tomography scans. Nearly all patients were treated nonoperatively (98.1%) and no deaths were reported in this study. Conclusions Patterns of injury, based on mechanism of injury, have been reported to assist the assessment and management of children with minor pelvic injuries. [ABSTRACT FROM AUTHOR]