Background: The use of vancomycin powder has been shown to decrease risk of surgical site infection (SSI) in early onset scoliosis (EOS). While there is potential benefit in SSI reduction, there is also theoretical risk in creating increased bacterial resistance to standard treatment regimens. However, the effects of topical vancomycin powder on microbiology in these patients has not been studied. Methods: A multicenter database for EOS patients was retrospectively analyzed. All patients that underwent surgical treatment with traditional growing rods, magnetically controlled growing rods, vertical expandable prosthetic titanium rib, and Shilla for EOS performed after 2010 were identified (n = 1115). Patients that sustained at least 1 SSI after guided growth surgery were assessed (n = 104, 9.3%). Patients with culture and antibiotic details were included (n = 55). Patients that received vancomycin powder at index surgery were compared with patients that did not. A multivariate regression model was used to control for potential confounders. Results: There were 55 patients included in this study, including 26 males (47%) and 29 females (53%). Mean age at index surgery was 7.2 ± 6.9 years. Vancomycin powder was utilized in 18 cases (33%). Mean time from index surgery to SSI was 2.0 ± 1.3 years. There were 2 cases of wound dehiscence (4%), 7 cases of superficial infection (13%), and 46 cases of deep infection (84%). There were significant differences in overall microbiology results between vancomycin and no vancomycin cohorts (P = 0.047). On univariate analysis, the vancomycin powder cohort had a significantly high incidence of cultures without growth (n = 7, 39% vs. n = 4, 11%, relative risk: 2.063, 95% confidence interval: 0.927-4.591, P = 0.028). This association remained significant on multivariate analysis (adjusted odds ratio: 9.656, 95% confidence interval: 1.743-53.494, P = 0.009). Conclusions: In EOS patients undergoing procedures complicated by SSI, the use of vancomycin powder was independently associated with increased risk of no culture growth. Surgeons and infectious disease physicians should be aware and adjust diagnostic and treatment strategies appropriately. Level of Evidence: Level III-retrospective cohort study.

Vertebrate pigmentation provides an ideal system for studying the intersections between evolution, genetics, and developmental biology. Teleost fish, with their accessible developmental stages and intense and diverse colours produced by chromatophores, are an ideal group for study. We set out to test whether Betta splendens is a good model organism for studying the evolution and development of diverse pigmentation. Our results demonstrate that B. splendens can be bred to produce large numbers of offspring with easily visualized pigment cells. Depending on the colour of the parents, there was variation in larval pigmentation patterns both within and between breeding events. In juveniles the developing adult pigmentation patterns showed even greater variation. These results suggest that B. splendens has great potential as a model organism for pigmentation studies.

No abstract

Introduction: Pediatric supracondylar humerus fractures are commonly evaluated using the anterior humeral line (AHL) on a lateral radiograph. Rotational variations in radiographic projection are common due to child discomfort and could lead to changes in management based on where the AHL intersects the capitellum. The purpose of this study was to establish whether rotational variations in elbow rotation leads to significant changes in AHL position and whether drawing the AHL based on the distal humerus versus shaft is more tolerant to rotation. Methods: Fifty children with nonoperative supracondylar humerus fractures were identified with sub optimally positioned injury and well positioned follow-up lateral radiographs. The proportion of the bone anterior to the intersection of the AHL and the capitellum was measured using the humeral shaft versus distal humerus to guide position of the AHL. This process was repeated on ten pediatric humerus dry cadaveric specimens which were imaged in 5-degree rotational increments along the axis of the humeral shaft from −20 to +20 degrees. Results: AHL position correlated poorly when measured on rotated lateral radiographs of clinical patients versus non-rotated lateral radiographs when using the distal humerus as a guide (intraclass correlation coefficient 0.14), compared with when using the humeral shaft as a guide (intraclass correlation coefficient 0.81). When assessing the pediatric humerus dry cadavers between the 2 techniques, there was greater statistically significant variation in rotated positions compared with the neutral position in the distal humerus AHL measurement approach compared with the humeral shaft AHL measurement approach, with the mean AHL within the central third of the capitellum for more rotational positions when using the shaft compared with the distal humerus. Conclusions: With rotated lateral elbow radiographs in supracondylar humerus fractures, utilizing the humeral shaft provides more consistent AHL measurements than utilizing the distal humerus, and thus drawing the line starting at the shaft of the humerus is recommended for surgical decision making.