about dynamic ultrasound and mri evaluation of partial patellar tendon tear
Today I show you the case of a partial tear at proximal insertion of the patellar tendon in a professional football player. The patient refears pain during flexion-extension at inferior patellar pole; hystory of repetitive trauma as usual in football players.
About the dynamic ultrasound study of the medial collateral ligament bursa.
Three layers can be defined on the medial compartment of the knee: layer I – crural fascia; Layer II – superficial portion of the medial collateral ligament; Layer III – joint capsule and the deep portion of the medial collateral ligament.
Along the course of layer II, the medial collateral ligament bursa may become apparent when filled with fluid; as happened in this patient after an intense session of horse riding.
Coronal Fast Stir (left) and T2 weighted Mri sequences (0.3 tesla).
All of bursae are typically founded in areas where friction takes place, such as between bony surfaces and ligaments or tendons.
The dynamic ultrasound examination better defines the fluid collection within the bursa;
If necessary, the elastosonography evalutaion allows to monitorate the evolution of fluid collection; in this patient is still evident the typical fluid appearance with three-layer colour pattern.
About weight-bearing ultrasound study of patellar tendon.
Take a look at this clinical case in which the patient with a clear evidence of patella alta and lateral patellar compression syndrome, has a tendinopathy of the patellar tendon at its proximal insertion, with chronic anterior knee pain and instability.
Sagittal T1w and Stir Mri sequences (0.3 tesla).
In orthostatism is most evident the increase of flow in vessels that are dilated because of inflammatory response.
This is the reason why I always perform the ultrasound examination both in clino and in orthostatism. Have you ever tried?
In a previous post I showed you my daily routine in studying patellar tendon degeneration and how crucial is to combine all the imaging modalities for a better treatment strategies.
It’s not easy to study post-surgical outcomes of a tendon with the Mri evaluation; lots of artifacts and calcfications doesn’t allow a clear visualization of tendon’s fibres.
Sagittal T1w (left) and GeStir (right) of patellar tendon degeneration 10 years after surgery reconstruction; red arrows indicate the site of pain.
This is the case of a patient that ten years after surgical reconstruction of the patellar tendon, starts to feel pain. Is it possible to “see” the pain? Gross tendon degeneration is evident but, only with ultrasound examination I can better depict the hypervascularity of the tendon in the site of referred pain and the relationship between patellar tendon and Hoffa’s fat pad, its well known “biomechanical attenuator”.
But I also asked to myself: what’s behind this tendon degeneration? Dynamic Mri study gave me the answer: a scarce patellar mobility during active flexion-extension movements was evident.
Less patellar mobility means more stress for the tendon. Isn’t it?
This is the case of a professional football player with a grade 2 injury of the medial collateral ligament; high signal and partial disruption of the ligament is seen on Mri exam. The study is completed by dynamic ultrasound and elastosonography evaluation; in this picture the elastosonography signal works like a “contrast agent”, with the red color that depicts the real extent of the ligament tear.
Have you ever tried to change the point of view of your ultrasound images? Takea look at the picture below, in which both Mri and ultrasound images have the same angle orientation.
Coronal T2w mri scan (0.3 Tesla) and ultrasound exam of the same patient.
Medial collateral ligament tear: from grade 1 to grade 3. T2w coronal Mri scans (0.3 Tesla).
Dynamic Mri exam is crucial in many situations; in a previous post I have shown a dynamic Mri study of patellofemoral impingement with patella alta.
Take a look at this patient in which the suspected patella baja is well studied during flexion-extension active movements.
The Insall-Salvati Index (ISI) and its modified version are used the same way on Mri studies as on plain radiographs.
Rember that in case of true patella baja, the patella remains engaged within the trochlear groove in full knee extension. The dynamic examination allows to appreciate the direct visualization of patellar and trochlear allignment for a more objective measurement, together with the others modalities. In this patient the dynamic examination shows a correct patellar positioning during active extension.