Psoriatic Arthritis of the Elbow

About chronic synovitis of the elbow in a patient with psoriatic arthritis.

Sometimes patients come to our attention without a specific clinical history, referring just joint pain.

In case of this joint swelling and gross chronic synovitis always think to a rheumatic disorder. Remember that on MRI, psoriatic synovitis appears indistinguishable from that of rheumatoid arthritis. According to the EULAR (European League Against Rheumatism) recommendations – “A definitive diagnosis of rheumatic diseases can be made by assessing the medical history, by performing a physical examination or ordering specific laboratory tests and undertaking imaging investigations”.


Coronal Ge Stir (left) and T1W Mri scans (0.3 Tesla).


Coronal GeStir (left) and Sagittal T2w (right) Mri scans (0.3 Tesla). A gross synovitis with pseudonodular distension of the bicipitoradialis bursa is evident.

The Mri examination shows diffuse irregularity of the cortical bone surfaces and entheseal region of tendons and ligaments, with distension of adjacent bursae by fluid collection. All of these findings are well depicted on ultrasound exam.

This patient also suffered for a painful synovial impingement along the course of the posterior interosseous nerve at Frohse’s arcade, best seen with the dynamic ultrasound examination.

With the elastosonography exam you can discriminate the real fluid quote of this chronic synovitis.

Avoid joint aspiration in this kind of situations: it’s like putting a needle into the marmalade! 

Take home message? Keep calm and call a rheumatologist.

Dynamic Mri of Patellofemoral Synovial Impingement

The knee has a particular anatomy with regard to the capsular-synovial relationship and contains several interposed fat pads. There is a limited amount of literature on suprapatellar fat pad anatomy of the knee and its pathology is likely underestimated due to underdiagnosis. Fat pad edema can be used as an indirect sign of synovial proliferation in patients with joint effusions. The most important symptom is chronic anterior knee pain proximal to the superior pole of the patella.


Axial T2w and Sagittal Ge-Stir (o.3 tesla) of a 20 years old patient with anterior knee pain. A clear picture of patellofemoral impingement is evident-

Prefemoral fat pad impingement may result from alterations in joint mechanics with repeated microtrauma between the patella and the anterior surface of the distal femur, especially on the lateral side of the fat pad. Mri examination is crucial for a correct diagnosis.

pf imping

Sagittal Ge-Stir and T1w Mri scans (0.3 Tesla); high degree femoro-patellar chondropathy with patella alta and suspected fat pad impingement

I really like the dynamic Mri exam because in my daily practice gives a further completion of the diagnosis, showing the effective amount of impingement during flexion-extension movements.

Dynamic Mri exam of the same patient