Hi, my name is Matt Miller. I'm one of the orthopedic residents of the University of Arizona. This project was done in the University of Arizona in conjunction with our MSK radiology colleagues and the focus of the project is the comparison of diagnostic ultrasound and MRI and the evaluation of perineal tendon injuries in correlation with operative findings. Disclosures, there are no relevant disclosures for this presentation. Just as a brief introduction, the peroneus brevis and longus run behind the distal fibula on a fibrosis tunnel created by the superior peroneal retinaculum. They act as active stabilizers to ankle and resisting inversion and they complement the static stabilizers to the ankles such as the ATFL and the CFL. Peroneal disorders are associated with lateral ankle sprains and the gambit of peroneal pathology includes tendinitis, tears, and subluxation. In terms of presentation, they present as the ankle sprain that won't heal, so that persists after three months, usually necessitated a full workup. At that time, the differential includes chronic ankle instability, peroneal tendinitis, peroneal tendon tear, peroneal subluxation, OC lesion of the tail, as well as syndesmotic injuries, and imaging plays a key role in differentiating them. So just looking at these normal images, we see longus and brevis on this axial MR image as well as we can see them highlighted here above on ultrasound. We can also see abnormal pathology on both ultrasound and MRI. So we have the sagittal stir MR image here on the left that shows this thickening of the PL tendon with that scattered signal, as well as we can see this kind of abnormal thickening on ultrasound. So is MR ultrasound better for diureneosine peroneal tendon pathology? So MR has the key advantage of being able to see all the soft tissue on the ankle and deal with any sort of or demonstrate any other injuries versus ultrasound, which is a live exam. So that's really nice because we can do things dynamically and show the ankle being loaded and unloaded and see how that changes how these, how the tendons are interacting. So in terms of previous studies, there's no study in the last 20 years directly comparing MRI and ultrasound against operative findings. There was one over 20 years ago, but at that time, MRI technology was very different from what we have now. So the final purpose of our study is to compare the diagnostic accuracy of ultrasound with MRI, the diagnosis of peroneal tendon injury in correlation with operative finding. So we had 21 patients with a suspected peroneal tendon injury, and they underwent both diagnostic ultrasound and MRI prior to surgery. All of these were reviewed by our MSK radiologists and they were all operated on by the same foot and ankle surgeon. In terms of what the MSK radiologists were doing for the MRI, there were two of them at all times looking for a longitudinal split tear, rupture, tenopathy, or subluxation. And they were blinded to the initial MRI reads and surgical results. The MRI findings were compared to surgical findings. Unfortunately, the ultrasounds were not reinterpreted. At the time of surgery, 13 of 21 patients had a PB tendon longitudinal split tear and three partial thickness tears. Two of 21 patients had a PL tendon tear, one complete rupture, and one longitudinal split tear. And 18 of 21 patients had tenonopathy and three intrasheath subluxation of the peroneal tendons. So just kind of highlighting what this, what a tear would look like. So this is a PB split tear. We can see on this axial MRI image, we can see it split as well as this patient also had a peroneus cortis or PQ. And we can see the same pathology highlighted here on ultrasounds. We can see that both imaging modalities have the ability to demonstrate pathology. Surgically, we treated this with a PB debridement and primary repair, as well as that PQ excision. In terms of the results of our study, the MRI results were concordant with surgical findings. So they were both 100% sensitive and specific for all tears. Ultrasound unfortunately failed to diagnose two longitudinal split tears. But ultrasound was better at diagnosing any intrasheath subluxation while MRI failed to detect two of the three. So the limitations of our study was that it was a very small number of patients. We also learned that ultrasound is very operator independent, operator dependent, I apologize. Two false negatives were found based on the same radiologist missing the split tears. In terms of future directions for our study, we'd like to conduct a larger study comparing MRI and ultrasound with surgery, and then also include ultrasound imaging performed by two examiners who'd be blinded to the MRI results rather than just one. So in conclusion, compared to ultrasound in our study, MRI showed slightly better results in the diagnosis of perineal tendon tears, but ultrasound was far more accurate in diagnosing intrasheath subluxations. Moving forward clinically, if we suspect subluxation in any of our patients on physical exam or patients complain of clicking or pain with movement, then we'd likely get an ultrasound addition to the MRI. I do also think there's a role that if cost is a major consideration, ordering ultrasound as the first line imaging and using that to diagnose patients with pathology. Thank you for your time.

ultrasound

MRI

peroneal tendon injuries

diagnostic accuracy

cost-effective option