What is the recommended imaging for Osgood-Schlatter disease?

Imaging for Osgood-Schlatter Disease

Plain radiography is the recommended first-line imaging modality for Osgood-Schlatter disease, with ultrasound being an excellent alternative that avoids radiation exposure. 1, 2

Diagnostic Approach

Initial Imaging

• Plain radiographs (X-rays):

  • Standard views should include:
    • Anteroposterior (AP) view
    • Lateral view
    • Sunrise/Merchant view (to evaluate patellofemoral joint)
  • Findings may include:
    • Soft tissue swelling over tibial tuberosity
    • Fragmentation of the tibial tubercle
    • Irregular ossification of the tibial tuberosity 1, 3

• Ultrasound (US):

  • Equally effective as radiographs with no radiation exposure
  • Can detect:
    • Thickening and increased echogenicity of distal patellar tendon
    • Anechoic zone of edema anterior to tibial tuberosity
    • Fragmentation of tibial tuberosity
    • Shell-like elevated fragments 2, 4

Advanced Imaging (when needed)

• MRI should be considered when:

  • Diagnosis remains unclear after initial imaging
  • Concomitant knee pathology is suspected (meniscal tears, ACL injury)
  • Need to characterize the stage and severity of the lesion 1, 5

• MRI findings may include:

  • Early stage: Edema-like changes around tibial tuberosity
  • Progressive stage: Partial avulsion of secondary ossification center
  • Terminal stage: Complete separation of avulsed parts
  • Healing stage: Osseous healing of separated parts 5

Clinical Correlation

• Imaging should be correlated with clinical presentation:
  • Typical symptoms include anterior knee pain, swelling, and tenderness over tibial tuberosity
  • Pain worsens with activity, especially jumping, running, and climbing stairs
  • Symptoms often bilateral (though may present unilaterally initially) 3, 6

Important Considerations

• In typical clinical presentations, some experts argue that imaging may not be necessary as diagnosis can be made clinically 6
• Routine imaging for follow-up is not recommended unless there is unexpected progression of symptoms 1
• Contralateral knee imaging is not routinely recommended in asymptomatic cases 1

Pitfalls to Avoid

• Don't rely solely on radiographs for early-stage disease as they may appear normal when pathology is present 5
• Don't mistake normal developmental variations of the tibial tubercle for pathologic findings
• Avoid unnecessary radiation exposure in adolescents by considering ultrasound as first-line imaging when available 2, 4

By following this imaging algorithm, clinicians can accurately diagnose Osgood-Schlatter disease while minimizing radiation exposure and unnecessary testing, leading to appropriate management and improved outcomes for affected patients.