Microbiology and Treatment Outcomes of Community-Acquired Hematogenous Osteoarticular Infections in Infants ≤12 Months of Age

Assessing Risk for Complications in Acute Hematogenous Osteomyelitis in Children: Validation of 2 Predictive Scores

BACKGROUND

Acute hematogenous osteomyelitis (AHO) can be associated with severe complications which can be difficult to predict in the clinical setting. The previously published predictive acute complication score ("A-SCORE") and chronic complication score ("C-SCORE") show promise, however, further external validation is needed.

METHODS

We performed a retrospective study of 418 children with AHO and analyzed the performance of A-SCORE (variables included bone abscess, fever after 48 h of starting antibiotics, suppurative arthritis, disseminated disease, and delayed source control) to predict risk for acute complicated course (treatment failure, prolonged admission, and/or need for ≥2 bone debridements) and C-SCORE (includes disseminated disease, bone debridement, and CRP ≥10 mg/dL at 2-4 days after starting antibiotics) to predict chronic complications (growth restriction, pathologic fracture, chronic osteomyelitis, avascular necrosis, joint deformity, and/or frozen joint).

RESULTS

An acute complicated course occurred in 106/418 (25.4%); 51/380 (13.5%) with complete follow-up data had a chronic complication. The A-SCORE performed with similar specificity (78%) and negative predictive value (NPV) (92%), and higher sensitivity (81%) and increased area under the receiver operating curve (AUC) (0.87) in our population. The C-SCORE performed with similar sensitivity (64%) and NPV (94%) but had lower specificity (86%) and AUC (0.71) than originally reported. Other variables associated with development of complications such as tibia involvement and bacteremia ≥2 days were identified but did not result in significantly improved predictive scores.

CONCLUSIONS

Predictive A-SCORE and C-SCORE for AHO complications in children may help guide acute management and long-term follow-up decisions. Prospective studies are needed to determine their applicability.

The Utility of IR-Guided Biopsy in the Treatment of Pediatric Osteomyelitis

BACKGROUND

Accurate and efficient diagnosis, as well as a consistent and effective treatment of acute hematogenous osteomyelitis, are paramount to ensure successful clinical outcomes. Noninvasive measures of isolating the causative pathogen from blood cultures have low sensitivity, with published rates often <50%. The use of interventional radiology (IR)-guided percutaneous biopsy has gained traction as a nonsurgical means of obtaining tissue cultures with a reported increased sensitivity of >90%. This study aims to determine the utility of IR-guided biopsy in the management of pediatric patients with acute hematogenous pediatric osteomyelitis (OM).

METHODS

An IRB-approved retrospective review was completed of children younger than 18 years admitted to a single institution for treatment of magnetic resonance imaging or culture/biopsy-proven acute hematogenous OM. Patients were excluded for the diagnosis of chronic recurrent multifocal OM, incomplete documentation, treatment initiation at an outside institution, open surgical debridement, and concomitant septic arthritis. Patients who underwent IR-guided biopsy were compared with those treated empirically without biopsy.

RESULTS

Fifty patients were included for analysis. Fifteen (30%) had IR-guided biopsies; 35 (70%) were treated empirically. The average age at diagnosis was 11.8 years old (SD: 4.9). Of the 15 patients who underwent IR-guided biopsy, a pathogen was identified in 12 cases (80%); 14 of these patients had concomitant blood cultures with only 1 (7%) positive result ( P <0.01). Of the 11 patients with positive IR-guided biopsy results in the setting of negative blood cultures, 9 (82%) had alterations in their antibiotic regimen as a result of the biopsy. The average time from blood sample collection to definitive antibiotic initiation was nearly double that of time from IR-guided biopsy collection to definitive antibiotic initiation (70.8 vs. 36 h; P <0.01).

CONCLUSION

IR-guided biopsy increased pathogen identification by 47% over blood cultures alone and decreased the time to definitive antibiotics. As such, IR-guided biopsy is an effective and safe diagnostic tool for pathogen identification and appropriate antibiotic selection. Orthopaedic surgeons are encouraged to incorporate IR-guided biopsy early in the treatment pathway for patients with acute OM without an indication for open surgical intervention.

LEVEL OF EVIDENCE

Level III; retrospective comparative study.

Predictive Factors to Guide Empiric Antimicrobial Therapy of Acute Hematogenous Osteomyelitis in Children

BACKGROUND

Acute hematogenous osteomyelitis (AHO) is a serious infection in children. Pediatric Infectious Diseases Society guidelines recommend empiric methicillin-resistant Staphylococcus aureus (MRSA) therapy in regions where MRSA accounts for more than 10-20% of all staphylococcal osteomyelitis. We sought to examine factors present at the time of admission which may predict etiology and guide empiric treatment for pediatric AHO in a region with endemic MRSA.

METHODS

We reviewed admissions with International Classification of Diseases 9/10 codes for AHO from 2011 to 2020 in otherwise healthy children. Medical records were reviewed for clinical and laboratory parameters present on the day of admission. Logistic regression was used to determine clinical variables independently associated with (1) MRSA infection and (2) non-Staphylococcus aureus infection.

RESULTS

A total of 545 cases were included. An organism was identified in 77.1% of cases and S. aureus was the most common (66.2%); 18.9% of all AHO cases were MRSA. Organisms besides S. aureus were identified in 10.8% of cases. CRP >7 mg/dL, subperiosteal abscess, history of any prior skin or soft tissue infection (SSTI) and need for intensive care unit admission were independently associated with MRSA infection. Vancomycin was used as an empiric treatment in 57.6% of cases. If the above criteria were relied upon to predict MRSA AHO, empiric vancomycin use could have been reduced by 25%.

CONCLUSIONS

Critical illness, CRP >7 mg/dL at the time of presentation, subperiosteal abscess and history of SSTI are suggestive of MRSA AHO, and could be considered when planning empiric therapy. Further work is needed to validate these findings before wider implementation.