Bursitis and Synovitis: Ultrasound Identification of Joint Inflammation
- Dr. Segnini
- Jan 14
- 2 min read
Visualizing Invisible Inflammation
Bursitis and synovitis are common manifestations of musculoskeletal pain and inflammation . High-resolution ultrasound has become the gold standard real-time imaging tool for their diagnosis, allowing differentiation from other pathologies and guiding precise interventions. Its high sensitivity in detecting fluid and soft tissue changes makes it superior to plain radiography in these conditions.
The Clinical Value of Ultrasound in Joint Inflammation:
Rapid Differential Diagnosis: Distinguishes between bursitis, synovitis, tendinopathy , muscle tears or osteoarthritis, which can present with similar pain.
Dynamic Visualization: Allows evaluation of joint movement and verification of whether a mass is compressible (liquid) or solid.
Minimal Fluid Detection: Identifies small effusions or early synovial thickenings, even before they are clinically evident.
Therapeutic Guide: It is essential for performing evacuation punctures or infiltrations with millimeter precision, increasing their effectiveness and safety.
Treatment Response Monitoring: Monitors the reduction of synovial fluid or thickening following medical or interventional therapy.
Key Ultrasound Findings:
A) Bursitis:
What it is: Inflammation of a serous sac ( bursa ), which is normally a virtual structure or one with very thin walls that facilitates sliding between tissue planes.
Ultrasound Findings:
Fluid in the Bursa: The distended bursa appears as an anechoic or hypoechoic structure (fluid) with well-defined borders.
Wall Thickening: In chronic or severe inflammatory cases, the synovial wall of the bursa thickens and may become hyperemic on Doppler ultrasound .
Color Doppler : Shows increased vascularization (hyperemia) in the bursa wall in cases of active inflammation.
Common Locations:
Subacromial-Subdeltoid Bursitis (Shoulder): Fluid between the rotator cuff and the acromion/deltoid.
Olecranon Bursitis (Elbow): "Student's elbow". Fluid behind the olecranon .
Prepatellar or Infrapatellar Bursitis (Knee): Superficial fluid anterior to the patella or over the patellar tendon.
Trochanteric Bursitis (Hip): Fluid over or around the greater trochanter, a common cause of lateral hip pain.
B) Synovitis:
What it is: Inflammation of the synovial membrane that lines the joint capsule and tendon sheaths.
Ultrasound Findings:
Pathological Synovial Thickening: The synovial membrane, normally imperceptible or very thin, thickens (>2 mm) and adopts a hypoechoic or mixed appearance (villi).
Joint Effusion: Presence of anechoic / hypoechoic fluid within the joint capsule.
Color Doppler : This is the key finding for defining inflammatory activity . Active synovitis shows an increased Doppler signal within the thickened synovial tissue (hyperemia), which differentiates it from inactive fibrous thickening.
Hairy Hypertrophy: In chronic cases ( e.g. , rheumatoid arthritis), the synovium may have an irregular proliferative appearance.
Limitations and Considerations:
It cannot adequately assess the inside of the bone or the deep cartilage in large joints (that's what MRI is for).
The detection of small intra-articular loose bodies ( osteophytes ) may be limited.
It requires a thorough anatomical knowledge to correctly identify normal and pathological structures.
Conclusion:
Musculoskeletal ultrasound is an extension of the physical examination that provides immediate anatomical and functional information. In the case of bursitis and synovitis, it not only confirms the diagnosis with high accuracy but also characterizes inflammatory activity (using Doppler ) and serves as a guide for interventional procedures, optimizing patient management in rheumatology, traumatology, and sports medicine.
Bursitis ultrasound
Dr. Jose Segnini, Radiologist / Diagnostic Medical Sonographer
MD Radiologist (Venezuela – Chile)
Board Certified Diagnostic Medical Sonographer (ARDMS, USA)
Mobile Ultrasound & Medical Supplies – Orlando, Florida
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