Age and CRP Associated With Improved Tissue Pathogen Identification in Children With Blood Culture Negative Osteomyelitis: Results From the CORTICES Multicenter Database.

BACKGROUND: Acute hematogenous osteomyelitis (AHO) is a relatively common condition in children, and identifying the offending pathogen with blood or tissue cultures aids in diagnosis and medical management while reducing treatment failure. Recent 2021 AHO clinical practice guidelines from the Pediatric Infectious Disease Society recommend obtaining routine tissue cultures, particularly in cases with negative blood cultures. The purpose of this study was to identify variables associated with positive tissue cultures when blood cultures are negative. METHODS: Children with AHO from 18 pediatric medical centers throughout the United States through the Children's ORthopaedic Trauma and Infection Consortium for Evidence-based Study were evaluated for predictors of positive tissue cultures when blood cultures were negative. Cutoffs of predictors were determined with associated sensitivity and specificity. RESULTS: One thousand three children with AHO were included, and in 688/1003 (68.6%) patients, both blood cultures and tissue cultures were obtained. In patients with negative blood cultures (n=385), tissue was positive in 267/385 (69.4%). In multivariate analysis, age ( P <0.001) and C-reactive protein (CRP) ( P =0.004) were independent predictors. With age >3.1 years and CRP >4.1 mg/dL as factors, the sensitivity of obtaining a positive tissue culture when blood cultures were negative was 87.3% (80.9-92.2%) compared with 7.1% (4.4-10.9%) if neither of these factors was present. There was a lower ratio of methicillin-resistant Staphylococcus aureus in blood culture-negative patients who had a positive tissue culture 48/188 (25.5%), compared with patients who had both positive blood and tissue cultures 108/220 (49.1%). CONCLUSION: AHO patients with CRP ≤ 4.1 mg/dL and age under 3.1 years are unlikely to have clinical value from tissue biopsy that exceeds the morbidity associated with this intervention. In patients with CRP > 4.1 mg/dL and age over 3.1 years, obtaining a tissue specimen may add value; however, it is important to note that effective empiric antibiotic coverage may limit the utility of positive tissue cultures in AHO. LEVEL OF EVIDENCE: Level III-Retrospective comparative study.

Practice Variation in the Surgical Management of Children With Acute Hematogenous Osteomyelitis.

INTRODUCTION: The surgical indications to manage children with acute hematogenous osteomyelitis (AHO) remain poorly defined. The purpose of this study was to identify if practice pattern variation exists in the surgical management of pediatric AHO among tertiary pediatric medical centers across the United States. A secondary purpose was to evaluate variables that may impact the rate of surgical intervention among these institutions. METHODS: Children with AHO were retrospectively analyzed between January 1, 2010, and December 31, 2016, from 18 pediatric medical centers throughout the United States. The rates of surgery were identified. Admission vitals, labs, weight-bearing status, length of stay, and readmission rates were compared between those who did and did not undergo surgery. Multivariate regression and classification and regression tree analyses were performed to identify the variables that were associated with surgical intervention. RESULTS: Of the 1003 children identified with AHO in this retrospective, multicenter database, 619/1003 (62%) were treated surgically. Multivariate analysis revealed institution, inability to ambulate, presence of multifocal infection, elevated admission C-reactive protein, increased admission platelet count, and location of the osteomyelitis were significant predictors of surgery (P<0.01). Patients who underwent surgery were more than twice as likely to have a recurrence or readmission and stayed a median of 2 days longer than those who did not have surgery. In the classification and regression tree analysis, 2 distinct patterns of surgical intervention were identified based on institution, with 12 institutions operating in most cases (72%), regardless of clinical factors. A second cohort of 6 institutions operated less routinely, with 47% receiving surgery overall. At these 6 institutions, patients without multifocal infection only received surgery 26% of the time, which increased to 74% with multifocal infection and admission erythrocyte sedimentation rate >37.5 mm/h. CONCLUSIONS: This study is the first to objectively identify significant differences in the rates of surgical management of pediatric AHO across the United States. Variation in the surgical management of AHO appears to be driven primarily based on institutional practice. Twelve institutions operated on 72% of patients, regardless of the severity of disease, indicating that the institution custom or dogma may drive the surgical indications. Six institutions relied more on clinical judgment with significant variability in rates of surgical intervention (26% vs. 74%), depending on the severity of the disease. Surgical intervention is associated with increased recurrence, readmission, and hospital length of stay. As a result of these findings, it is essential to prospectively study the appropriate surgical indications and measure the outcomes in children with pediatric AHO. LEVEL OF EVIDENCE: Level III.

Motion laboratory gait analysis and orthopedic resident education: preliminary results.

Gait analysis in the pediatric and adult orthopedic patient populations can adjunct the diagnosis and treatment of a multitude of musculoskeletal conditions. Understanding of normal and abnormal gait biomechanics is an important aspect of orthopedic residency; yet, there is great variability in the time residency programs dedicate to gait analysis education. The purpose of this study was to investigate if formal gait analysis education during residency improves an orthopedic resident's understanding of normal and pathologic gait. Five residency programs consisting of 81 resident subjects were surveyed at the beginning of the 2016-2017 academic year. The residents were divided into those with formal gait analysis education (group A) and those without (group B). Each resident was sent an online survey with 11 questions from former orthopedic in-training exams (OITE) regarding gait pattern analysis. The average number of correct questions was compared between the two groups with Student's t-test. Fifty-three of the 81 surveys sent out were completed. There were 23 subjects in group A and 30 in group B. All five programs and all postgraduate years (PGYs) were represented (PGY1: 10, PGY2: 12, PGY3: 12, PGY4: 6, PGY5 12). The average score for all residents was 5.6 out of 11 correct (51%). The residents from group A averaged a significantly higher score (6.3) than group B (5.0) (P = 0.017). Understanding gait biomechanics is a critical skill for orthopedic surgeons, and residency training often lacks sufficient training in their curriculum. A good understanding of gait analysis allows orthopedic surgeons to analyze gait disturbances and develop patient-specific treatment plans in adult and pediatric populations. This study found improved knowledge of gait patterns amongst orthopedic residents with formal education. Even though the residents with formal education fared better than their counterparts, the overall percent correct was still low (51%). Evidence: Level 3: Prospective Cohort Study.

Postoperative Urinary Retention after Pediatric Orthopedic Surgery.

Purpose: This study aims to describe the incidence of postoperative urinary retention among pediatric patients undergoing orthopedic surgery and identify risk factors. Methods: The Pediatric Health Information System was used to identify children aged 1−18 years who underwent orthopedic surgery. Collected from each patient's record were demographic information, principal procedure during hospitalization, the presence of neurologic/neuromuscular conditions and other complex chronic medical conditions, the total postoperative length of stay, and the presence of postoperative urinary retention. Results: The overall incidence of postoperative urinary retention was 0.38%. Children with complex chronic neuromuscular conditions (OR 11.54 (95% CI 9.60−13.88), p = < 0.001) and complex chronic non-neuromuscular medical conditions (OR 5.07 (95% CI 4.11−6.25), p ≤ 0.001) had a substantially increased incidence of urinary retention. Surgeries on the spine (OR 3.98 (95% CI 3.28−4.82, p ≤ 0.001) and femur/hip (OR 3.63 (95% CI 3.03−4.36), p ≤ 0.001) were also associated with an increased incidence. Conclusions: Children with complex chronic neuromuscular conditions have a substantially increased risk of experiencing postoperative urinary retention. Complex chronic non-neuromuscular medical conditions and surgeries to the spine, hip, and femur also carry a notably increased risk.

The modified Kocher criteria for septic hip: Does it apply to the knee?

Background: Pediatric septic arthritis is a surgical emergency and timely diagnosis prevents serious complications. To differentiate between septic hip and transient synovitis, the predictive value of four original Kocher criteria (fever, inability to bear weight, elevated serum white blood cell count, and elevated erythrocyte sedimentation rate) plus Caird's addition of elevated C-reactive protein have been studied, termed the modified Kocher criteria. These criteria have not been tested extensively on septic knee. This study tested the utility of the modified Kocher criteria in predicting septic knee while validating it for septic hip. Methods: A retrospective chart review was conducted of pediatric patients evaluated at a single institution for irritable hip or knee between 2009 and 2018. Patients who underwent arthrocentesis were included and the modified Kocher criteria were applied to all. Results: One hundred fifty-five patients (96 hips and 59 knees) were identified. One hundred four (67.1%) patients had septic arthritis with 44/59 (74.6%) of knees and 60/96 (62.5%) of hips. The strongest predictors for septic hip and knee were elevated C-reactive protein (odds ratio = 26.9, p < 0.0001) and refusal to bear weight (odds ratio = 14.5, p < 0.0001), respectively. For hips, 5/5 criteria produced a 100% positive predictive value for septic arthritis. For knees, the combination of inability to bear weight and elevated C-reactive protein had a positive predictive value of 89.7%. Conclusion: While all five of the modified Kocher criteria are not predictive of pediatric septic knee, the combination of two specific factors (inability to bear weight and elevated C-reactive protein) is strongly predictive. This study validates previous work that the modified Kocher criteria are predictive of septic hip. Level of evidence: level III.