Preliminary Diagnosis: Septic Arthritis

I. What imaging technique is first-line for this diagnosis?

  • Plain radiograph.

  • As clinically suspected septic arthritis is a clinical emergency, image-guided joint aspiration is advocated as the first-line imaging technique.

II. Describe the advantages and disadvantages of this technique for diagnosing septic arthritis.

Advantages

  • Quickly and accurately detects moderate to large joint effusions, the first radiographic sign of septic arthritis.

    Continue Reading

  • Accurately detects sequela of septic arthritis: periarticular osteoporosis, joint space narrowing, and marginal erosions.

  • Provides superior resolution of the osseous structures.

Disadvantages

  • Findings are nonspecific, and joint aspiration is required if septic arthritis is clinically suspected.

  • May not detect small joint effusion.

  • Exposes the patient to a small amount of ionizing radiation.

III. What are the contraindications for the first-line imaging technique?

No significant absolute contraindications exist. Some institutions require consent for pregnant patients.

IV. What alternative imaging techniques are available?

  • Ultrasound

  • MRI with gadolinium.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing septic arthritis.

Ultrasound
Advantages

  • Highly sensitive for detecting joint effusion, if superficial.

  • Does not require the use of ionizing radiation.

  • May be employed for needle guidance for joint aspiration.

Disadvantages

  • Limited to evaluating joints that are superficial.

  • Findings are nonspecific, and joint aspiration is required if septic arthritis is clinically suspected.

  • Nonspecific for type of joint effusion.

  • Inferior to plain film for osseous detail.

MRI with gadolinium
Advantages

  • Highly sensitive and relatively specific in the appropriate clinical setting.

  • Can accurately identify complications associated with septic arthritis, such as adjacent soft tissue abscess or cellulitis.

  • Does not expose the patient to ionizing radiation.

Disadvantages

  • Findings are often nonspecific and joint aspiration is required if septic arthritis is clinically suspected.

  • Provides less osseous detail compared to plain radiographs.

  • Expensive.

  • Time consuming imaging modality.

  • Requires significant patient cooperation to minimize motion artifact.

VI. What are the contraindications for the alternative imaging techniques?

Ultrasound

No significant contraindications exist.

MRI with gadolinium

  • MR imaging is contraindicated in patients with non-MR compatible metallic hardware or foreign bodies.

  • Gadolinium contrast is contraindicated in patients with a GFR ≤ 30.

Copyright © 2017, 2013 Decision Support in Medicine, LLC. All rights reserved.

No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.

Jump to Section