Clinical Scores Predict Acute and Chronic Complications in Pediatric Osteomyelitis: An External Validation

Early Bone Ischemia in Pediatric Acute Hematogenous Osteomyelitis and its Association With Progression to Chronic Osteomyelitis: New Insights From Gadolinium-enhanced Subtraction MRI

BACKGROUND

Acute hematogenous osteomyelitis (AHO), the most common osteoarticular infection in children, carries a significant risk for chronic complications. Predicting chronic complications early in the course of disease is challenging. The underlying pathogenesis of complications is not fully understood.

METHODS

Children who presented to Sultan Qaboos University Hospital, Muscat, Oman between January 2015 and April 2022 for AHO were identified by a search of magnetic resonance imaging (MRI) records. Children between 1 month and 18 years of age who did not meet exclusion criteria, and whose MRI also included gadolinium-enhanced subtraction (GES) sequences were included in the analysis. Outcomes were compared between patients who showed early evidence of bone ischemia and those who did not.

RESULTS

The analysis included 11 children who had GES MRI sequences from among 18 AHO cases in total. Median age was 5 years (IQR, 4-9), and 82% were males. Median duration of symptoms at presentation was 5 days (IQR, 3-7). GES sequences showed early bone ischemia in 6 of 11 (55%) patients. Patients with early bone ischemia were treated with significantly longer durations of IV antibiotics (median 23 vs. 10 days, P = 0.017) and oral antibiotics (median 134 vs. 29 days, P = 0.004), and required more surgical debridements (median 3 vs. 0 debridements, P = 0.017). Chronic osteomyelitis only developed among patients with early bone ischemia (5/6 vs. 0/5, P = 0.015).

CONCLUSIONS

In pediatric AHO, GES MRI sequences revealed early bone ischemia in a significant proportion of patients. Early bone ischemia was strongly associated with progression to chronic osteomyelitis.

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.

Primary Fibular Osteomyelitis in Children: A Systematic Review

Osteomyelitis of the fibula is rare and is especially rare in children. The published literature is limited to case series and is thus lacking a comprehensive description of the disease. The purpose of this systematic review is to provide the first comprehensive summary of the demographics, presenting symptoms, laboratory values, microbiology, and treatment results of osteomyelitis of the fibula in children based on the existing literature. This institutional review board (IRB)-exempt systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) guidelines. Three search engines were used for a total of 239 studies. Twenty-six studies were screened by full text. Twelve articles underwent a quantitative analysis. Due to limited data and heterogenous reporting, the data were summarized descriptively. The methodologic quality of the studies was evaluated based on the Newcastle-Ottawa scale. The average age was 7.71±3.49 years, and males comprised 57% of the 21 cases. The most common presenting symptoms were fever (86%), antalgic gait (57%), and localized tenderness (81%). The most common site of involvement was the distal third of the fibula (90%). The average C-reactive protein (CRP) was 90.1±38.3 mg/L, and the average erythrocyte sedimentation rate (ESR) was 58.8±21.2 mm/hour. Staphylococcus aureus was the most cultured pathogen reported in 10/21 cases (48%). Open surgery was performed in 17/21 cases (81%), and there were no reported complications. Fever, antalgic gait, and localized tenderness should raise the index of suspicion. Prompt laboratory and radiographic evaluations can help reduce delays in diagnosis and improve outcomes. Blood and tissue cultures are currently performed in about half of the cases. Improvement in our microbiologic diagnosis has the potential to improve antibiotic selection. Local methicillin-resistant Staphylococcus aureus (MRSA) prevalence must be taken into consideration when starting empiric antibiotic treatment. Surgical treatment is often required with a low complication rate. The clinical and laboratory parameters identified in this study have the potential for integration into a composite clinical score.

Pediatric musculoskeletal infections

PURPOSE OF REVIEW

The aim of this article is to review the recent guidelines and literature regarding the diagnosis and the treatment of common pediatric musculoskeletal infections: septic arthritis, osteomyelitis, pyomyositis, and Lyme disease.

RECENT FINDINGS

In the last decade, a better understanding of the causative organisms of common bacterial infections, including Kingella , leads to prompt targeted antimicrobial coverage in all musculoskeletal infections. Prompt diagnosis and treatment continues to be the mainstay in the treatment of children with osteoarticular infections. Efforts to improve early detection have lead to improving rapid lab diagnostic testing; however, more advanced diagnostics such as arthrocentesis for septic arthritis and MRI for osteomyelitis and pyomyositis, remain the gold standard. Shorter and narrowed antibiotic courses, with appropriate transition to outpatient oral treatment provide effective infection clearance and reduction in complications of disease.

SUMMARY

Advances in diagnostics, including pathogen identification as well as imaging continues to improve our ability to diagnose and treat these infections, although still lack ability to provide definitive diagnosis without more invasive nor advanced techniques.

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.