Lyme Arthritis in the Pediatric Knee: Clinical and Magnetic Resonance Imaging Differentiators.

Lyme disease is the most prevalent tick-borne illness in the United States, especially endemic in the Northeast and Upper Midwest. Distinguishing Lyme arthritis (LA), the most common manifestation of the disease in children, from septic arthritis (SA) can be challenging because of overlap in clinical presentations. This study examined the role of magnetic resonance imaging (MRI) as an adjunct to clinical and laboratory features used to differentiate between LA and SA in children and adolescents. Methods: The medical records and MRI scans of children who presented between 2009 and 2019 with an acute knee effusion ultimately diagnosed as LA or SA were retrospectively reviewed. Data collection included clinical information on the modified Kocher criteria (weight-bearing, fever, blood serology including white blood-cell [WBC] count, C-reactive protein [CRP], and erythrocyte sedimentation rate [ESR]), MRI findings, and serology confirmation of LA or bacterial SA. A total of 87 cases of confirmed LA and 9 cases of SA were identified. Results: The 2 cohorts had substantial clinical overlap with regard to the ability to bear weight, fever, and joint aspirate WBC count. Differences between the 2 groups in several MRI characteristics, specifically vastus lateralis myositis, subcutaneous edema, and lymphadenopathy, were significant. A multivariate analysis demonstrated that weight-bearing, CRP of <3 mg/L, absence of subcutaneous edema, myositis of multiple muscles including the vastus lateralis, and lymphadenopathy were predictive of LA. Conclusions: LA should be strongly suspected in endemic areas of the United States when children present with a knee effusion. The addition of MRI criteria to clinical and laboratory findings significantly improved the predictive value for identifying LA. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incarcerated Medial Epicondyle Fractures With Elbow Dislocation: Risk Factors Associated With Morbidity.

BACKGROUND: Incarcerated medial epicondyle fractures in association with elbow trauma are rare and an absolute indication for intervention. Because of the infrequent nature, outcomes following this injury are not well documented. We studied a large cohort of these injuries to determine factors associated with functional outcomes. It was hypothesized that a greater duration between initial presentation and time of surgery would lead to poorer outcomes. METHODS: A total of 32 patients aged 18 and under who underwent surgical treatment for an incarcerated medical epicondyle fracture at a level-1 pediatric trauma center from 2003 to 2015 were identified. All patients had a confirmed diagnosis of an incarcerated medial epicondyle at surgery. Medical records and radiographs were reviewed to determine the patient demographics, mechanism of injury, preoperative neurological symptoms, time of primary presentation, time of elbow reduction, and time to surgical intervention. Postoperative outcomes, including pain, range of motion, and ulnar nerve symptoms, were also collected. The Roberts outcome score was determined for each subject. RESULTS: A radiographically confirmed elbow dislocation was identified in 25 subjects. The mean age at injury was 13.2 years (range, 7.3 to 17.8 y). Initial presentation was at a referring institution in 30 patients (94%). First closed reduction attempt of the ulnohumeral joint occurred in the emergency room in 24 subjects (75%); of these 7 subjects (22%) had a first reduction attempted in the emergency room at our institution, 2 patients experienced first elbow reduction during surgical intervention. The median time from first presentation to surgery was 21.9 hours (interquartile range, 15 to 40). Fourteen subjects displayed preoperative ulnar nerve symptoms. Of these, 9 subsequently reported postoperative ulnar nerve symptoms. There was no effect of time to surgical intervention on the Roberts outcome scores at follow-up, nerve symptoms, symptomatic hardware, or need for second surgery to remove hardware. There were 16 subjects with excellent outcomes, 13 with good outcomes, 3 with fair outcomes, and 0 with poor outcomes (based on the Roberts criteria). CONCLUSIONS: Incarcerated medial epicondyle fractures are commonly associated with ulnar nerve symptoms; however, they are not associated with a significant rate of other complications. There was no increased risk of complications in subjects who had a longer duration between initial presentation and surgery. This suggests that, while the presence of an incarcerated medial epicondyle fracture is certainly an indication for timely operative intervention; the injury in isolation does not need to be considered emergent. Other factors including neurovascular status and ability to achieve joint reduction may still necessitate emergency operative care. LEVEL OF EVIDENCE: Level IV-therapeutic study, case series.

Reliability of Radiographic Assessments of Adolescent Midshaft Clavicle Fractures by the FACTS Multicenter Study Group.

OBJECTIVES: There is a recent trend toward increased surgical treatment of displaced midshaft clavicle fractures in adolescents. The primary purpose of this study was to evaluate the intrarater and interrater reliability of clavicle fracture classification systems and measurements of displacement, shortening, and angulation in adolescents. The secondary purpose was to compare 2 different measurement methods for fracture shortening. METHODS: This study was performed by a multicenter study group conducting a prospective, comparative, observational cohort study of adolescent clavicle fractures. Eight raters evaluated 24 deidentified anteroposterior clavicle radiographs selected from patients 10-18 years of age with midshaft clavicle fractures. Two clavicle fracture classification systems were used, and 2 measurements for shortening, 1 measurement for superior-inferior displacement, and 2 measurements for fracture angulation were performed. A minimum of 2 weeks after the first round, the process was repeated. Intraclass correlation coefficients were calculated. RESULTS: Good to excellent intrarater and interrater agreement was achieved for the descriptive classification system of fracture displacement, direction of angulation, presence of comminution, and all continuous variables, including both measurements of shortening, superior-inferior displacement, and degrees of angulation. Moderate agreement was achieved for the Arbeitsgemeinschaft für Osteosynthesefragen classification system overall. Mean shortening by 2 different methods were significantly different from each other (P < 0.0001). CONCLUSIONS: Most radiographic measurements performed by investigators in a multicenter, prospective cohort study of adolescent clavicle fractures demonstrated good-to-excellent intrarater and interrater reliability. Future consensus on the most accurate and clinically appropriate measurement method for fracture shortening is critical.

Trends in the volume of operative treatment of midshaft clavicle fractures in children and adolescents: a retrospective, 12-year, single-institution analysis.

The purpose of this study was to examine institutional trends in the volume of clavicle fractures in children and adolescents. Medical records were retrospectively reviewed to identify patients aged 10-18 years treated for a clavicle fracture between 1999 and 2011 at a single tertiary-care pediatric hospital. There were significant increases in the number of clavicle fractures seen annually, of midshaft clavicle fractures, and of midshaft clavicle fractures treated operatively. The percentage of midshaft clavicle fractures treated with fixation also increased significantly. The volumes of clavicle fractures and midshaft clavicle fractures treated operatively appear to be increasing. Despite a lack of evidence-based support, the frequency of fixation of midshaft clavicle fractures appear to be increasing in the pediatric population.

Management of pediatric patients with synovial fluid white blood-cell counts of 25,000 to 75,000 cells/mm³ after aspiration of the hip.

BACKGROUND: In this study, we sought to elucidate the presentation, clinical course, treatments pursued, final diagnosis, and risk factors for septic arthritis in a series of children with hip pain and intermediate synovial fluid values (white blood-cell [WBC] counts of 25,000 to 75,000 cells/mm(3) [25 to 75 × 10(9) cells/L]). METHODS: We reviewed the records of pediatric patients who underwent hip aspiration between 2005 and 2012 at a tertiary-care pediatric hospital. Demographic data, laboratory values, final diagnosis, and treatment details were recorded for the subpopulation of patients with an aspirate WBC count of 25,000 to 75,000 cells/mm(3) (25 to 75 × 10(9) cells/L). Univariate and multivariable logistic regression analysis was used to assess risk factors for septic arthritis of the hip across final diagnostic groups and subgroups with WBC values of <50,000 and ≥50,000 cells/mm(3) (<50 and ≥50 × 10(9) cells/L). RESULTS: Forty-six children (twenty-seven males and nineteen females) with a mean age of 7.6 years met the inclusion criteria. The final diagnoses were septic arthritis of the hip (n = 15; 33%), Lyme arthritis (n = 13; 28%), transient synovitis (n = 8; 17%), and other findings (n = 10; 22%). Subjects with a synovial fluid WBC count of ≥50,000 cells/mm(3) (≥50 × 10(9) cells/L) were more likely to be diagnosed with septic arthritis of the hip (odds ratio, 4.4; 95% confidence interval, 1.1 to 16.9; p = 0.03). While septic arthritis of the hip was the most common diagnosis (48%) in patients with WBC values of ≥50,000 cells/mm(3) (≥50 × 10(9) cells/L), it also represented 17% of cases with WBC values of <50,000 cells/mm(3) (<50 × 10(9) cells/L). CONCLUSIONS: Septic arthritis of the hip is the most common ultimate diagnosis in children with synovial fluid WBC values of 25,000 to 75,000 cells/mm(3) (25 to 75 × 10(9) cells/L) following hip aspiration, and it should be high on the differential diagnosis, even in cases with synovial fluid WBC values of <50,000 cells/mm(3) (<50 × 10(9) cells/L).