High-Resolution US and MR Imaging of Peroneal Tendon Injuries

Abstract

Injuries of the peroneal tendon complex are common and should be considered in every patient who presents with chronic lateral ankle pain. These injuries occur as a result of trauma (including ankle sprains), in tendons with preexisting tendonopathy, and with repetitive microtrauma due to instability. The peroneus brevis and peroneus longus tendons are rarely torn simultaneously. Several anatomic variants, including a flat or convex fibular retromalleolar groove, hypertrophy of the peroneal tubercle at the lateral aspect of the calcaneus, an accessory peroneus quartus muscle, a low-lying peroneus brevis muscle belly, and an os peroneum, may predispose to peroneal tendon injuries. High-resolution 1.5-T and 3-T magnetic resonance (MR) imaging with use of dedicated extremity coils and high-resolution ultrasonography (US) with high-frequency linear transducers and dynamic imaging are proved to adequately depict the peroneal tendons for evaluation and can aid the orthopedic surgeon in injury management. An understanding of current treatment approaches for partial- and full-thickness peroneal tendon tears, subluxation and dislocation of these tendons with superior peroneal retinaculum (SPR) injuries, intrasheath subluxations, and peroneal tendonopathy and tenosynovitis can help physicians achieve a favorable outcome. Patients with low functional demands do well with conservative treatment, while those with high functional demands may benefit from surgery if nonsurgical treatment is unsuccessful. Radiologists should recognize the normal anatomy and specific pathologic conditions of the peroneal tendons at US and MR imaging and understand the various treatment options for peroneal tendon and SPR superior peroneal retinaculum injuries. Online supplemental material is available for this article.

Surgical Management of Lateral Ankle Instability in Athletes

“…Magnetic resonance imaging is also used to determine the presence of an osteochondral lesion, whereas ultrasound is better for detecting transient subluxation or dislocation of the peroneal tendons. 18…”

The peroneus longus muscle and tendon: a review of its anatomy and pathology

“…A hypoechoic appearance can signify tendinosis, although nonperpendicular probe positioning can cause artifactual hypoechogenicity from anisotropy [8]. Partial peroneus longus tendon tears may appear as hypoechoic tendon thinning or thickening with a fluid-filled defect, whereas full-thickness tears appear as longitudinal splitting or complete fiber discontinuity with retraction [8,9].…”

“…More distally, peroneus longus tendinosis, tears and tenosynovitis at the retromalleolar groove and cuboid tunnel can be seen in detail. Importantly, MRI can identify concurrent pathology responsible for lateral hindfoot symptoms, including osteochondral and lateral ligamentous injuries [9,10].…”

“…Artifactual regions of increased signal on short echo time (TE) sequences are common below the fibula due to magic angle artifact, simulating tendinosis ( Figure 3); this finding is related to organized collagen fibers within tendons orientated at 55°to the B 0 axis of the main magnetic field. This artifact can be reduced by increasing TE (especially on PD fat-suppressed sequences), using prone positioning or placing the foot in 20°of plantar flexion [9].…”

Imaging of Tendons

“…Tendinopathy more commonly affects the peroneus brevis tendon. Split peroneus brevis syndrome represents a longitudinal tear of the tendon and the term arises from the fact that the peroneus brevis tendon is usually located anteriorly, is embedded between the peroneus longus and fibula [33,34,38].…”