Knee Pain in Children: Part I: Evaluation

Fever and Knee Effusion in the Pediatric Patient

ABSTRACT

The pediatric patient with fever and knee effusion is always a cause for clinical concern. A thorough history and physical examination is required to guide appropriate diagnostic evaluation and management. Although pediatric knee effusions are common in the setting of trauma, the presence of fever should prompt consideration of infectious, rheumatologic, vasculitic, and malignant etiologies. This review covers the key components of the history, physical examination, diagnostic strategies, common etiologies, and initial management of the pediatric patient with fever and knee effusion.

Overuse Knee Pain in the Pediatric and Adolescent Athlete

Overuse knee pain is common in young athletes. There are many potential overuse injuries which present with insidious onset of pain that can challenge sports medicine providers, including Osgood-Schlatter's disease, patellofemoral syndrome, osteochondritis dissecans, and stress fractures. The differential diagnosis of insidious onset knee pain also includes malignancies, infections, and rheumatologic issues. A thorough history and physical examination can guide the treating provider in making a diagnosis and appropriate treatment plan. Although not always necessary, imaging is often helpful in overuse knee pain, and laboratory workup may be necessary. Conservative treatment is often the first recommendation in the management of overuse knee pain in young athletes, and this may include activity modification, ice, anti-inflammatory medications, bracing, and physical therapy. This review summarizes common overuse knee injuries seen in pediatric and adolescent athletes.

Patellofemoral Pain

Patellofemoral pain (PFP) is a common musculoskeletal-related condition that is characterized by insidious onset of poorly defined pain, localized to the anterior retropatellar and/or peripatellar region of the knee. The onset of symptoms can be slow or acutely develop with a worsening of pain accompanying lower-limb loading activities (eg, squatting, prolonged sitting, ascending/descending stairs, jumping, or running). Symptoms can restrict participation in physical activity, sports, and work, as well as recur and persist for years. This clinical practice guideline will allow physical therapists and other rehabilitation specialists to stay up to date with evolving PFP knowledge and practices, and help them to make evidence-based treatment decisions. J Orthop Sports Phys Ther. 2019;49(9):CPG1-CPG95. doi:10.2519/jospt.2019.0302.

Ruptured Appendicitis and Retrocecal Abscess Masquerading as Knee Pain in a Pediatric Patient: A Case Report

BACKGROUND

Knee pain has a variety of etiologies in the pediatric population, including septic arthritis, osteomyelitis, fracture, ligamentous injury, and neoplasms. Extrinsic sources of knee pain may also be intra-abdominal, although abdominal pathology is much more likely to manifest as hip or proximal thigh musculature pain.

CASE REPORT

A 5-year-old healthy male presented with atraumatic right knee pain, discomfort with weightbearing, fever, and elevated inflammatory laboratory markers. Physical examination and magnetic resonance imaging findings of the knee were benign, leading to low clinical suspicion for knee septic arthritis. Blood cultures were positive for a gastrointestinal organism, Granulicatella adiacens, suggesting abdominal pathology leading to referred pain. Ultrasound evaluation and computed tomography (CT) of the abdomen revealed a large abscess secondary to perforated appendicitis, which was treated with CT-guided drainage and i.v. antibiotics. The patient's musculoskeletal pain subsided with treatment of the appendicitis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Acute appendicitis may present as knee pain, with other signs and symptoms mimicking septic arthritis, such as fever, inability to bear weight, and elevated inflammatory markers. Considering an array of differential diagnoses in pediatric patients with apparent knee septic arthritis is crucial to prevent delay in diagnosis of alternative infectious sources.