Defining the volume of consultations for musculoskeletal infection encountered by pediatric orthopaedic services in the United States

A Rapid MRI Protocol for the Evaluation of Acute Pediatric Musculoskeletal Infections: Eliminating Contrast and Decreasing Anesthesia, Scan Time, and Hospital Length of Stay and Charges

BACKGROUND

Acute musculoskeletal infection affects >1 in 6,000 children in the United States annually. Magnetic resonance imaging (MRI) is the gold standard for the diagnosis of musculoskeletal infection, but it traditionally requires contrast and anesthesia for children, delaying management. A rapid MRI protocol involves MRI without anesthesia and with limited non-contrast sequences optimized for fluid detection and diffusion-weighted images to identify abscesses. We hypothesized that a rapid MRI protocol would improve imaging and treatment efficiency for pediatric patients undergoing musculoskeletal infection evaluation without substantially affecting accuracy.

METHODS

This was a single-center, retrospective study of patients undergoing evaluation for musculoskeletal infection before (60 patients in the traditional cohort [TC]) and after (68 patients in the rapid cohort [RC]) implementation of the rapid MRI protocol. Sociodemographic and clinical variables were extracted from electronic health records, and statistical comparisons were performed.

RESULTS

The anesthesia rates were 53% for the TC and 4% for the RC, and the contrast administration rates were 88% for the TC and 0% for the RC. The median time to MRI after ordering was 6.5 hours (95% confidence interval [CI], 5.0 to 8.6 hours) for the TC and 2.2 hours (95% CI, 1.4 to 3.6 hours) for the RC (p < 0.01). The median duration of MRI was 63.2 minutes (95% CI, 56.8 to 69.6 minutes) for the TC and 24.0 minutes (95% CI, 21.1 to 29.5 minutes) for the RC (p < 0.01). The median hospital length of stay was 5.3 days (95% CI, 3.7 to 6.9 days) for the TC and 3.7 days (95% CI, 1.9 to 4.1 days) for the RC (p < 0.01). The median hospital charges were $47,309 (95% CI, $39,137 to $58,769) for the TC and $32,824 (95% CI, $22,865 to $45,339) for the RC (p < 0.01). Only 2 positive cases of musculoskeletal infection in the RC were missed on the initial imaging, but these instances were not attributable to the rapid protocol itself. Although 10 of 68 rapid MRI scans resulted in nondiagnostic outcomes due to patient motion, only 6 of 68 required repeat MRI with anesthesia.

CONCLUSIONS

In patients evaluated for musculoskeletal infection, the rapid MRI protocol eliminated contrast and minimized anesthesia while improving MRI access and decreased scan and interpretation times, hospital length of stay, and hospital charges. The rapid MRI protocol had high sensitivity for diagnosing musculoskeletal infection and a low rate of imaging failure.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Navigating the Enigma of Pediatric Musculoskeletal Infections: A Race Against Time

Musculoskeletal infection (MSKI) in children is a critical condition in pediatric orthopedics due to the potential for serious adverse outcomes, including multiorgan dysfunction syndrome, which can lead to death. The diagnosis and treatment of MSKI continue to evolve with advancements in infectious organisms, diagnostic technologies, and pharmacologic treatments. It is imperative for pediatric orthopedic surgeons and medical teams to remain up to date with the latest MSKI practices.

A rare complication of a rare pediatric injury: Transient drop foot following a floating knee injury

Floating Knee is a rare injury caused by high velocity, and has rarely been described in children. The purpose of this report is to present a case of a six-year-old female after a fall down three and a half flights of stairs, suffering from this rare injury and a rare complication, and her rehabilitation. She suffered fractures of the femur and tibia (Floating Knee type), and was operated on the day of the injury with closed reduction and internal fixation (CRIF). Following the operation, painful drop-foot was evident, related to the fractured bone pressure on the sciatic nerve and a very high level of anxiety. The patient was transferred to a rehabilitation hospital, where she received a total of about 350 physical therapy, hydrotherapy, psychology and occupational therapy treatments over a period of one year. Treatment also consisted of an ankle-foot orthosis (AFO) and transcutaneous electrical stimulation, and were assisted with examinations at the motion analysis laboratory using surface electromyography. The combined orthopedic and physical therapy treatment, and cooperation with psychology in the intervention and training for the care team, enabled achievement of all rehabilitation goals. The patient returned to a high functional level and full participation in daily life activities with her peers, without the need for the AFO or further treatment in the community. A re-examination after about six months showed continued functional improvement according to objective indicators. This case raises awareness of rare injuries and complications in pediatric orthopedic patients, that require multidisciplinary rehabilitation treatment and cooperation between the surgical and rehabilitation teams. Closed injury of the sciatic nerve can be followed for a long period without additional invasive studies or formal nerve exploration, and complete recovery can be achieved.

Comparison of Procalcitonin With Commonly Used Biomarkers and Algorithms for Evaluating Suspected Pediatric Musculoskeletal Infection in the Emergency Department

INTRODUCTION

It is difficult to distinguish between children with infectious versus noninfectious conditions of the musculoskeletal system during initial evaluation. Clinical predictive algorithms potentially support this effort but not without limitations. Procalcitonin (PCT) has been proposed as a biomarker to help differentiate infection from noninfection. This study evaluates the adoption and utility of PCT during initial infection evaluations and assesses test characteristics of commonly used parameters and algorithms.

METHODS

PCT was introduced for initial laboratory evaluation of the suspected musculoskeletal infection. Prospective enrollment occurred from July 2020 to November 2021 with 3 cohorts established after a retrospective review of final diagnoses at the end of treatment: 1) deep infection, 2) superficial infection, and 3) noninfection. Univariate and multivariate logistic regression analysis of parameters and diagnoses was performed. Test characteristics of individual and aggregated parameters were assessed.

RESULTS

Among 258 children evaluated, 188 (72.9%) had PCT drawn during the evaluation. An increase of PCT acquisition from 67.8% to 82.4% occurred over the study timeframe. Eighty-five children were prospectively studied, including those with deep infection (n=21); superficial infection (n=10), and noninfection (n=54). Test characteristics of parameters showed accuracy ranging from 48.2% to 85.9%. PCT >0.1 ng/mL independently predicted deep infection in 84.7% of cases, outperforming white blood cell, C-reactive protein (CRP), and absolute neutrophil count. Using study thresholds for CRP, erythrocyte sedimentation rate, PCT, and Temp improved accuracy to 89.4%.

CONCLUSIONS

PCT is a potentially useful biomarker during the initial assessment of children suspected to have a musculoskeletal infection. Systematic evaluation using a combination of parameters improves the accuracy of assessment and assists predictive judgment under uncertainty. PCT <0.1 ng/mL, erythrocyte sedimentation rate <18 mm/hr, CRP <3.3 mg/dL, and temperature <37.8°C should reasonably reassure clinicians that deep musculoskeletal infection is less likely, given the high negative predictive value and collective accuracy of these parameters.

LEVEL OF EVIDENCE

Level III - Retrospective cohort comparison.

Descriptive Epidemiology of Upper Extremity Septic Arthritis in Children-Review of a Retrospective Multicenter Database

BACKGROUND

There is limited information on the presentation and management of upper extremity septic arthritis (UESA) in children. Our purpose was to report on the characteristics and short-term treatment outcomes of pediatric UESA from a multicenter database.

METHODS

Patients with UESA were identified from a multicenter retrospective musculoskeletal infection database. Demographics, laboratory tests, culture results, number of surgeries, and complications were collected.

RESULTS

Of 684 patients with septic arthritis (SA), 68 (10%) patients had UESA. Septic arthritis was most common in the elbow (53%), followed by the shoulder (41%) and wrist (4%). The median age at admission was 1.7 years [interquartile range(IQR, 0.8-8.0 y)] and 66% of the cohort was male. Blood cultures were collected in 65 (96%) patients with 23 (34%) positive results. Joint aspirate and/or tissue cultures were obtained in 66 (97%) patients with 49 (72%) positive results. Methicillin-sensitive Staphylococcus aureus (MSSA) was the most common causative organism overall, but Streptococcus was the most common pathogen in the shoulder. Sixty-six (97%) patients underwent irrigation and debridement, with 5 (7%) patients requiring 2 surgeries and 1 patient (1%) requiring 3 surgeries. The median length of stay was 4.9 days (IQR, 4.0-6.3 d). Thirty-one (46%) children had adjacent musculoskeletal infections and/or persistent bacteremia. No patients experienced venous thromboembolism, and 4 patients with associated osteomyelitis experienced a musculoskeletal complication (3 avascular necrosis, 1 pathologic fracture). One child had re-admission and 3 children with associated osteomyelitis had a recurrence of UESA. Comparison between elbow and shoulder locations showed that children with septic arthritis of the shoulder were younger (4.6 vs. 1.0 y, P =0.001), and there was a difference in minimum platelet count (280 vs. 358 ×10 9 cells/L, P =0.02).

CONCLUSIONS

UESA comprises 10% of cases of septic arthritis in children. The elbow is the most common location. Shoulder septic arthritis affects younger children. MSSA is the most common causative organism in UESA, but Streptococcus is common in shoulder septic arthritis. Irrigation and debridement result in excellent short-term outcomes with a low complication rate. Re-admissions and repeat surgical interventions are rare.

LEVEL OF EVIDENCE

Level IV, prognostic.

Characteristics of Children With Culture Negative Acute Hematogenous Musculoskeletal Infections

BACKGROUND

Identifying the causative pathogen for acute hematogenous musculoskeletal infections (MSKIs) allows for directed antimicrobial therapy and diagnostic confidence. However, 20% to 50% of children with acute MSKIs remain culture negative. The objective of this study was to compare characteristics of culture negative MSKI patients to those where a pathogen is identified.

METHODS

Electronic medical records of children admitted between July 2014 to September 2018 to a single quaternary care pediatric hospital with acute MSKIs were retrospectively reviewed. Clinical and demographic characteristics were compared between culture positive and culture negative MSKIs.

RESULTS

A total of 170 patients were included of whom 43 (25%) were culture negative. All culture negative patients had at least 1 culture type obtained, and the majority (84%) had both blood and source cultures performed. When compared with patients with a causative pathogen identified, culture negative patients were younger (2.3 vs. 9.8 y), smaller (13.5 vs. 31.6 kg), less likely to be febrile on arrival (56% vs. 77%), less likely to have an abscess on imaging (23% vs. 48%), and were more likely to have uncomplicated septic arthritis (35% vs. 8%). No critically ill patient was culture negative. Seven culture negative patients had additional Kingella kingae testing performed, none of which were positive.

CONCLUSIONS

Despite targeted and standardized efforts to identify causative bacteria, 25% of children with acute MSKIs never have a pathogen identified. Culture negative patients are younger, less febrile, are less likely to have an abscess, and more likely to have isolated septic arthritis.

LEVEL OF EVIDENCE

This is a retrospective cohort study interested in identifying patient characteristics that predict rate of culture positivity for acute MSKIs. This study meets criteria for Level II evidence.

Primary Septic Arthritis Among Children 6 to 48 Months of Age: Implications for PCR Acquisition and Empiric Antimicrobial Selection

INTRODUCTION

Primary septic arthritis requires unique evaluation and treatment considerations for children in the 6- to 48-month age range because of the spectrum of identified pathogens and high rate of negative cultures. The purpose of this study is to evaluate primary septic arthritis in this age group in order to differentiate children with infection caused by Kingella kingae from those with other confirmed pathogens and those with no identified pathogen.

METHODS

Preschool children who underwent multidisciplinary evaluation and treatment for septic arthritis between 2009 and 2019 were retrospectively studied. Three cohorts were established for comparison of clinical and laboratory features of primary septic arthritis: (1) confirmed K. kingae, (2) confirmed other pathogen, and (3) presumed (without identified pathogen).

RESULTS

Among 139 children with septic arthritis, 40 (29%) were confirmed K. kingae, 29 (21%) other pathogen, and 70 (50%) presumed. Children with Kingella and those with presumed septic arthritis had significantly lower initial C-reactive protein (4.8 and 4.5 vs. 9.3 mg/dL) and fewer febrile hospital days (0.2 and 0.4 vs. 1.3 d) than children with other confirmed pathogens. Children with other pathogens had higher rates of bacteremia (38% vs. 0%) and positive joint fluid cultures (86% vs. 15%) than that of children with Kingella. The rate of polymerase chain reaction (PCR) acquisition was 38 of 40 (95.0%) Kingella cases, 18 of 29 (62.1%) other pathogen cases, and 33 of 70 (47.1%) presumed cases.

CONCLUSIONS

K. kingae was the most commonly identified pathogen among 6-month to 4-year-old children. The Kingella and other identified pathogens in this study serve to guide empiric antimicrobial recommendations for this age range. Because of similarities between children with septic arthritis because of K. kingae and those with no identified pathogen, it is likely that an unrecognized burden of Kingella resides in culture negative cases, particularly if no PCR is sent. Systematic evaluation, including PCR acquisition, and a high index of suspicion for K. kingae are recommended to thoroughly evaluate septic arthritis in preschool children.

LEVEL OF EVIDENCE

Level III-Retrospective cohort comparison.

Correction: Defining the volume of consultations for musculoskeletal infection encountered by pediatric orthopaedic services in the United States

[This corrects the article DOI: 10.1371/journal.pone.0234055.].