MRI of tibial stress fractures: relationship between Fredericson classification and time to recovery in pediatric athletes.

BACKGROUND: Tibial stress fractures are not uncommon in pediatric athletes. The severity of injury may be graded using magnetic resonance imaging (MRI). OBJECTIVE: To determine whether Fredericson MRI grading of tibial stress fractures can differentiate times to recovery across different grades in pediatric athletes. MATERIALS AND METHODS: A medical record search identified all athletes younger than 19 years old who had tibial stress fractures confirmed by MRI and were treated by sports medicine specialists in our clinic system over a 5-year period. Two pediatric radiologists graded MRI exams using the Fredericson system. Time to recovery (in days) was defined in four ways: pain onset to full participation, pain onset to zero pain, first treatment to full sport participation and first treatment to zero pain. Recovery times were compared to tibial stress fracture Fredericson MRI grade and to the use of a recovery device. RESULTS: Thirty-eight pediatric athletes (age range: 7-18 years, mean: 15.4±2.2 years) had 42 tibial stress fractures while participating in 12 different sports. About half (55%) were track and/or cross-country athletes. The mean time from diagnosis to report of no pain for all patients was 55.6±5.0 days. We found no significant difference in time to recovery across stress fracture grade or with the use of a recovery device. CONCLUSION: No differences were noted between Fredericson stress fracture grades and different time periods to recovery or between differences in recovery time and the return to full participation in sports, regardless of the use of assistive devices.

Clinical and Radiologic Manifestations of Bone Infection in Children with Cat Scratch Disease.

We identified 13 patients with cat scratch (Bartonella henselae) bone infection among those admitted to a large tertiary care children's hospital over a 12-year period. The median age was 7 years and the median time from onset of illness to diagnosis was 10 days. Multifocal osteomyelitis involving spine and pelvis was common; no patient had a lytic bone lesion. Median treatment duration was 28 days (IQR, 24.5 days). Despite significant variations in treatment duration and antimicrobial therapy choices, all patients showed improvement.

Pulmonary Nodule Size <5 mm Still Warrants Investigation in Patients With Osteosarcoma and Ewing Sarcoma.

BACKGROUND: Osteosarcoma (OS) and Ewing sarcoma (ES) have a high propensity to develop pulmonary metastases. Lung lesions with calcification, peripheral location, and size >5 mm are more likely to represent malignant metastases. We evaluated the incidence of malignancy in nodules 5 mm or less to potentially guide decisions between biopsy and observation. MATERIALS AND METHODS: A retrospective review of patients <25 years of age with metastatic OS and ES treated at our institution between 2001 and 2014 who had undergone pulmonary nodule biopsy was performed. Computed tomographic scans were reviewed to evaluate nodule size and change over time. RESULTS: Thirty-five patients (27 OS, 8 ES) met inclusion criteria. One hundred sixteen nodules were biopsied (97 OS, 19 ES). Nodule size at biopsy was not significantly different between the malignant (median, 6 mm, range, 1 to 79 mm) and benign (median, 3 mm, range, 1 to 21 mm) lesions (P=0.063). Size of pulmonary nodules <5 mm was not entirely predictive of benign status, with sensitivity estimate of 0.709 (95% confidence interval, 0.465-0.872; P=0.091) and specificity estimate of 0.776 (95% confidence interval, 0.324-0.962; P=0.219) for all nodules biopsied. CONCLUSIONS: Pulmonary nodules in patients with OS and ES <5 mm cannot be excluded from biopsy considerations.

Ultrasound-guided corticosteroid injection of the subtalar joint for treatment of juvenile idiopathic arthritis.

BACKGROUND: The subtalar joint is commonly affected in children with juvenile idiopathic arthritis and is challenging to treat percutaneously. OBJECTIVE: To describe the technique for treating the subtalar joint with US-guided corticosteroid injections in children and young adults with juvenile idiopathic arthritis and to evaluate the safety of the treatment. MATERIALS AND METHODS: We retrospectively analyzed 122 patients (age 15 months-29 years) with juvenile idiopathic arthritis who were referred by a pediatric rheumatologist for corticosteroid injection therapy for symptoms related to the hindfoot or ankle. In these patients the diseased subtalar joint was targeted for therapy, often in conjunction with adjacent affected joints or tendon sheaths of the ankle. We used a protocol based on age, weight and joint for triamcinolone hexacetonide or triamcinolone acetonide dose prescription. We describe the technique for successful treatment of the subtalar joint. RESULTS: A total of 241 subtalar joint corticosteroid injections were performed under US guidance, including 68 repeat injections for recurrent symptoms in 26 of the 122 children and young adults. The average time interval between repeat injections was 24.8 months (range 2.2-130.7 months, median 14.2 months). Subcutaneous tissue atrophy and skin hypopigmentation were the primary complications observed. These complications occurred in 3.9% of the injections. CONCLUSION: With appropriate training and practice, the subtalar joint can be reliably and safely targeted with US-guided corticosteroid injection to treat symptoms related to juvenile idiopathic arthritis.

Dynamic Volumetric Computed Tomography Angiography is an Effective Method to Evaluate Tracheomalacia in Children.

OBJECTIVE: Standard methods to evaluate tracheal pathology in children, including bronchoscopy, may require general anesthesia. Conventional dynamic proximal airway imaging in noncooperative children requires endotracheal intubation and/or medically induced apnea, which may affect airway mechanics and diagnostic performance. We describe a technique for unsedated dynamic volumetric computed tomography angiography (DV-CTA) of the proximal airway and surrounding vasculature in children and evaluate its performance compared to the reference-standard of rigid bronchoscopy. METHODS: Children who had undergone DV-CTA and bronchoscopy in one-year were retrospectively identified. Imaging studies were reviewed by an expert reader blinded to the bronchoscopy findings of primary or secondary tracheomalacia. Airway narrowing, if present, was characterized as static and/or dynamic, with tracheomalacia defined as >50% collapse of the tracheal cross-sectional area in exhalation. Pearson correlation was used for comparison. RESULTS: Over a 19-month period, we identified 32 children (median age 8 months, range 3-14 months) who had undergone DV-CTA and bronchoscopy within a 90-day period of each other. All studies were unsedated and free-breathing. The primary reasons for evaluation included noisy breathing, stridor, and screening for tracheomalacia. There was excellent agreement between DV-CTA and bronchoscopy for diagnosis of tracheomalacia (κ = 0.81, p < 0.001), which improved if children (n = 25) had the studies within 30 days of each other (κ = 0.91, p < 0.001). CTA provided incremental information on severity, and cause of secondary tracheomalacia. CONCLUSION: For most children, DV-CTA requires no sedation or respiratory manipulation and correlates strongly with bronchoscopy for the diagnosis of tracheomalacia. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:410-416, 2023.

Clinical change 2 years from start of elexacaftor-tezacaftor-ivacaftor in severe cystic fibrosis.

RATIONALE: Limited published research is available on the impact of elexacaftor/tezacaftor/ivacaftor (ETI) beyond the initial few months postdrug initiation, especially for those who initiated therapy via individual investigational new drug application. The experiences of patients with cystic fibrosis (CF) experiencing severe lung disease were reviewed for significant improvements in clinical symptoms and quality of life. OBJECTIVES: To examine clinical outcomes 2 years post-ETI in patients with CF and advanced lung disease. METHODS: This single center institutional review board-approved, retrospective chart review assessed clinical markers (percent predicted forced expiratory volume in 1 s, weight, sweat chloride), quality of life and computed tomography scans in patients with advanced lung disease who met criteria for compassionate use/expanded access program due to high risk of death or transplant need within 2 years. RESULTS: Eighteen identified patients (ages 15-49 years) initiated drug between July and September 2019. Clinical markers indicated that therapy was well tolerated, not discontinued by any participant, and lab values did not indicate medical concern or discontinuation. Monitoring results indicated the safety of modulator therapy as there were no adverse clinical occurrences and all patients presented universal stabilization. There were no deaths and no transplants by the end of the study. CONCLUSIONS: This study focused on patients with CF eligible for modulator therapy and were initiated due to advanced lung disease. Initiation of modulator therapy was deemed safe and resulted in objective positive changes in nutrition, cough, FEV1 , subjective reports of clinical status, level of activity, and a reduction in burden of treatment.

Ultrasound-guided corticosteroid injection therapy for juvenile idiopathic arthritis: 12-year care experience.

BACKGROUND: Intra-articular corticosteroid injections are a safe and effective treatment for patients with juvenile idiopathic arthritis. The potential scope of care in ultrasound-guided corticosteroid therapy in children and a joint-based corticosteroid dose protocol designed to optimize interdisciplinary care are not found in the current literature. OBJECTIVE: The purpose of this study was to report the spectrum of care, technique and safety of ultrasound-guided corticosteroid injection therapy in patients with juvenile idiopathic arthritis and to propose an age-weight-joint-based corticosteroid dose protocol. MATERIALS AND METHODS: A retrospective analysis was performed of 198 patients (ages 21 months to 28 years) referred for treatment of juvenile idiopathic arthritis with corticosteroid therapy. Symptomatic joints and tendon sheaths were treated as prescribed by the referring rheumatologist. An age-weight-joint-based dose protocol was developed and utilized for corticosteroid dose prescription. RESULTS: A total of 1,444 corticosteroid injections (1,340 joints, 104 tendon sheaths) were performed under US guidance. Injection sites included small, medium and large appendicular skeletal joints (upper extremity 497, lower extremity 837) and six temporomandibular joints. For patients with recurrent symptoms, 414 repeat injections were performed, with an average time interval of 17.7 months (range, 0.5-101.5 months) between injections. Complications occurred in 2.6% of injections and included subcutaneous tissue atrophy, skin hypopigmentation, erythema and pruritis. CONCLUSION: US-guided corticosteroid injection therapy provides dynamic, precise and safe treatment of a broad spectrum of joints and tendon sheaths throughout the entire pediatric musculoskeletal system. An age-weight-joint-based corticosteroid dose protocol is effective and integral to interdisciplinary care of patients with juvenile idiopathic arthritis.

Accuracy of Chest Computed Tomography in Distinguishing Cystic Pleuropulmonary Blastoma From Benign Congenital Lung Malformations in Children.

Importance: The ability of computed tomography (CT) to distinguish between benign congenital lung malformations and malignant cystic pleuropulmonary blastomas (PPBs) is unclear. Objective: To assess whether chest CT can detect malignant tumors among postnatally detected lung lesions in children. Design, Setting, and Participants: This retrospective multicenter case-control study used a consortium database of 521 pathologically confirmed primary lung lesions from January 1, 2009, through December 31, 2015, to assess diagnostic accuracy. Preoperative CT scans of children with cystic PPB (cases) were selected and age-matched with CT scans from patients with postnatally detected congenital lung malformations (controls). Statistical analysis was performed from January 18 to September 6, 2020. Preoperative CT scans were interpreted independently by 9 experienced pediatric radiologists in a blinded fashion and analyzed from January 24, 2019, to September 6, 2020. Main Outcomes and Measures: Accuracy, sensitivity, and specificity of CT in correctly identifying children with malignant tumors. Results: Among 477 CT scans identified (282 boys [59%]; median age at CT, 3.6 months [IQR, 1.2-7.2 months]; median age at resection, 6.9 months [IQR, 4.2-12.8 months]), 40 cases were extensively reviewed; 9 cases (23%) had pathologically confirmed cystic PPB. The median age at CT was 7.3 months (IQR, 2.9-22.4 months), and median age at resection was 8.7 months (IQR, 5.0-24.4 months). The sensitivity of CT for detecting PPB was 58%, and the specificity was 83%. High suspicion for malignancy correlated with PPB pathology (odds ratio, 13.5; 95% CI, 2.7-67.3; P = .002). There was poor interrater reliability (κ = 0.36 [range, 0.06-0.64]; P < .001) and no significant difference in specific imaging characteristics between PPB and benign cystic lesions. The overall accuracy rate for distinguishing benign vs malignant lesions was 81%. Conclusions and Relevance: This study suggests that chest CT, the current criterion standard imaging modality to assess the lung parenchyma, may not accurately and reliably distinguish PPB from benign congenital lung malformations in children. In any cystic lung lesion without a prenatal diagnosis, operative management to confirm pathologic diagnosis is warranted.

A cellular isolation system for real-time single-cell oxygen consumption monitoring.

The development of a cellular isolation system (CIS) that enables the monitoring of single-cell oxygen consumption rates in real time is presented. The CIS was developed through a multidisciplinary effort within the Microscale Life Sciences Center (MLSC) at the University of Washington. The system comprises arrays of microwells containing Pt-porphyrin-embedded polystyrene microspheres as the reporter chemistry, a lid actuator system and a gated intensified imaging camera, all mounted on a temperature-stabilized confocal microscope platform. Oxygen consumption determination experiments were performed on RAW264.7 mouse macrophage cells as proof of principle. Repeatable and consistent measurements indicate that the oxygen measurements did not adversely affect the physiological state of the cells measured. The observation of physiological rates in real time allows studies of cell-to-cell heterogeneity in oxygen consumption rate to be performed. Such studies have implications in understanding the role of mitochondrial function in the progression of inflammatory-based diseases, and in diagnosing and treating such diseases.