What is the appropriate evaluation and management of bilateral knee pain in a pediatric patient?

Bilateral Knee Pain in Pediatric Patients: Evaluation and Management

Initial Approach

Start with a thorough clinical assessment without imaging in the absence of red flags, as most pediatric knee pain is self-limiting and benign. 1, 2

The evaluation should focus on identifying specific red flags that warrant immediate imaging or specialist referral, rather than reflexively ordering studies.

Critical History Elements

Obtain the following specific information:

• Timing and onset: Acute trauma versus insidious onset 1, 2
• Bilateral versus unilateral symptoms: True bilateral pain suggests systemic, inflammatory, or overuse etiologies rather than traumatic injury 3
• Ability to bear weight: Inability to take four weight-bearing steps suggests fracture 1
• Neurologic symptoms: Weakness, numbness, or radicular patterns 1
• Constitutional symptoms: Fever, weight loss, night pain suggesting infection or malignancy 1, 2
• Activity level: Intensity of youth sports participation, recent increases in training 1
• Location specificity: Anterior (patellar tendinopathy, Osgood-Schlatter), medial/lateral (meniscal), or diffuse 3

Physical Examination Priorities

Perform a targeted examination including:

• Focal tenderness over specific structures: Palpate tibial tubercle, patellar tendon, joint line, patella 1, 2
• Joint effusion: Presence suggests intra-articular pathology 1, 4
• Range of motion: Both active and passive 1, 2
• Gait assessment: Antalgic gait, inability to bear weight 1
• Neurologic examination: Strength, sensation, reflexes 1
• Hip examination: Range of motion, impingement signs, groin pain to exclude referred pain 3, 5
• Spine examination: Evaluate for lumbar radiculopathy as a source of referred pain 3, 5

Red Flags Requiring Imaging

Obtain imaging when any of the following are present:

• Acute trauma with focal tenderness or effusion 1
• Inability to bear weight (cannot take four steps) 1
• Constitutional symptoms: Fever, night pain, weight loss 1, 2
• Neurologic deficits 1
• Palpable mass 1
• Persistent pain despite 4-6 weeks of conservative management 6

Initial Imaging Strategy

For acute trauma meeting Ottawa knee rule criteria (age ≥5 years with focal tenderness, effusion, or inability to bear weight), obtain plain radiographs as the first-line study. 1, 6

• Minimum two views: anteroposterior and lateral (at 25-30 degrees flexion) 1
• Additional views as indicated: patellofemoral, oblique views for specific concerns 1

For chronic bilateral knee pain without red flags, imaging is not indicated initially. 1, 6

Advanced Imaging Indications

MRI should be reserved for specific scenarios and is not a first-line study: 6

• Radiographs normal but symptoms persist after conservative treatment 6
• Surgical intervention being considered 6
• Suspected osteochondritis dissecans (OCD) requiring characterization 1, 3
  • Note: Hyperintense rim or cysts at fragment periphery are less specific for instability in children compared to adults 1, 3
• Suspected occult fracture not visible on radiographs 1

Common Pediatric-Specific Diagnoses for Bilateral Knee Pain

Consider these age-appropriate etiologies:

• Osgood-Schlatter disease: Anterior knee pain, tibial tubercle tenderness in adolescents 3, 7
• Sinding-Larsen-Johansson syndrome: Inferior patellar pole pain 3
• Patellofemoral pain syndrome: Overuse, increased sports intensity 1, 2
• Juvenile idiopathic arthritis: Constitutional symptoms, morning stiffness 2
• Growing pains: Bilateral, evening/night occurrence, no objective findings 2

Critical Pitfalls to Avoid

• Do not overlook referred pain from hip or lumbar spine pathology 3, 5

  • Always examine the hip with range of motion and impingement testing 3
  • Evaluate for lumbar radiculopathy patterns 3

• Do not order MRI without recent radiographs (within past year) 3

  • Approximately 20% of patients inappropriately undergo MRI without prior radiographs 3

• Do not assume MRI findings are clinically significant in isolation 3

  • Asymptomatic meniscal tears are common, especially in older adolescents 3

• Recognize that abdominal pathology can present as knee pain 8

  • Consider appendicitis if fever and elevated inflammatory markers present 8

Conservative Management

For bilateral knee pain without red flags, initiate conservative treatment for 4-6 weeks before considering imaging: 1, 6

• Activity modification and relative rest 1, 2
• Physical therapy focusing on strengthening and flexibility 2, 4
• NSAIDs for pain control 2
• Ice application 2

Reassess after conservative treatment; if symptoms improve, no imaging is needed. 1