Related Experiment Video
Updated: Oct 7, 2025
Novel Diagnostics in Revision Arthroplasty: Implant Sonication and Multiplex Polymerase Chain Reaction
Published on: December 3, 2017
Novel Uses of Traditional Algorithms for Septic Arthritis
Amanda J Nickel1, Brianna S Bretscher1, Walter H Truong2
1Children's Minnesota Research Institute.
Background:
Pediatric musculoskeletal infection (MSKI) is a bacterial infection of the bone, joint, and/or muscle that can be difficult to diagnose. The Kocher and Caird algorithms were developed to distinguish septic arthritis (SA) from transient synovitis (TS) in the hip. These algorithms have been applied to all patients presenting with painful, swollen monoarticular joints regardless of suspicion for SA. The aim of this analysis was to assess the test performance of Kocher and Caird to distinguish MSKI among all pediatric patients presenting with monoarticular joint pain. A secondary aim was to validate the original algorithms.
Methods:
We conducted a secondary analysis of a prospective cohort study evaluating the test performance of procalcitonin for suspected SA in a pediatric emergency department. Patients aged 0 to 16 years old who presented with a painful or swollen monoarticular joint were considered for enrollment. We compared the test performance of the traditional algorithms in an expanded population of MSKI versus alternate joint pain using sensitivity, specificity, and area under the curve (AUC). As a sensitivity analysis, missing data for predictors like temperature, erythrocyte sedimentation rate, C-reactive protein, and inability to bear weight were multiply imputed using the Stata program, mi impute, for changed equations.
Results:
The Caird algorithm had better test performance compared to the Kocher in all populations. Both algorithms were most discriminative in comparing SA to TS in all joints (AUC: 0.84 Caird and 0.75 Kocher). However, the Caird criteria performed almost as well discriminating MSKI from other causes of monoarticular joint pain in all joints (AUC: 0.79; 95% confidence interval: 0.72, 0.85) and nonhip joints (AUC: 0.80; 95% confidence interval: 0.71, 0.88).
Conclusion:
Based on the findings of this study, it is clinically reasonable to apply the Caird algorithm to pediatric patients presenting with monoarticular joint pain of medium and large joints such as the knee, ankle, shoulder, elbow, and wrist, in addition to the hip.
Level Of Evidence:
Level III-retrospective study of novel applications of SA algorithms.
Insights
The Caird algorithm effectively distinguishes pediatric musculoskeletal infections from other causes of joint pain, outperforming the Kocher algorithm. This study supports its broader clinical application beyond the hip.
Area of Science:
- Pediatric Orthopedics
- Infectious Diseases
- Diagnostic Accuracy
Background:
- Pediatric musculoskeletal infection (MSKI) presents diagnostic challenges.
- Existing Kocher and Caird algorithms primarily target septic arthritis (SA) in the hip.
- Current application of these algorithms extends beyond their original scope.
Purpose of the Study:
- To evaluate the diagnostic test performance of the Kocher and Caird algorithms for MSKI in pediatric patients with monoarticular joint pain.
- To compare the discriminative ability of these algorithms in an expanded patient population.
- To validate the original algorithms' utility.
Main Methods:
- Secondary analysis of a prospective cohort study in a pediatric emergency department.
- Inclusion of patients aged 0-16 with painful or swollen monoarticular joints.
- Comparison of algorithm performance using sensitivity, specificity, and AUC, with multiple imputation for missing data.
Main Results:
- The Caird algorithm demonstrated superior test performance over the Kocher algorithm across all evaluated populations.
- Both algorithms were most effective in differentiating septic arthritis (SA) from transient synovitis (TS) (AUC: 0.84 Caird, 0.75 Kocher).
- The Caird criteria showed strong discrimination for MSKI versus other causes of monoarticular joint pain in all and non-hip joints (AUC: 0.79 and 0.80, respectively).
Conclusions:
- The Caird algorithm is clinically reasonable for diagnosing MSKI in pediatric patients with monoarticular joint pain.
- Its application can be extended to medium and large joints beyond the hip, including the knee, ankle, shoulder, elbow, and wrist.
Related Concept Videos
01:28Acute Pyelonephritis II: Diagnostic Studies and Management
01:18Endocarditis III: Medical Management
01:27Acute Pyelonephritis I: Introduction
01:25Urinary Tract Calculi VI: Surgical Management
01:27Combined Effects of Drugs: Synergism
Such synergistic combinations...