Isolated partial tear of extensor digitorum longus tendon with overlying muscle herniation in acute ankle sports injury: role of high resolution musculoskeletal ultrasound

Jeena Bordoloi Deka,Mohit V Shah,Ferdinando Draghi,Chandra Bortolotto,Fernando Jimenez,Nilim Kumar Deka

doi:10.1007/s40477-021-00572-0

Abstract

Lateral Ankle sprain is a common sports-related trauma with the mechanism of injury ranging from inversion to plantar flexion. These injuries commonly affect the ligaments but can also affect the associated soft tissue structures like the eversion muscles and tendons. Prompt and accurate diagnosis of such injuries is warranted so as to ensure early return to play and prevent long-term complications. Lateral ankle sprain injuries in sports may not always be associated with ligament injuries. We report a never before reported case of lateral ankle sprain injury in a soccer player with the unusual finding of isolated partial tear of Extensor digitorum longus muscle and its fascia leading to myo-fascial herniation. The lateral ankle ligaments were intact. The diagnosis was clinched on a high-frequency ultrasound scan supported by dynamic maneuvers which in fact proved to be superior to MRI as the latter failed to demonstrate the myo-fascial herniation in our case. We therefore propose that real-time ultrasound scanning with dynamic maneuvers should be the first line of investigation to assess sports injuries in anatomically complex joints like the ankle.

Highlights

A myo-fascial herniation refers to a focal protrusion of the muscle tissue through a defect in its fascia into the overlying subcutaneous tissue
The tibialis anterior muscle is the most common leg muscle involved hernias of extensor digitorum longus, peroneus longus and gastrocnemius have been reported
We have not found any published case of acute inversion and plantar flexion ankle injury resulting in a combination of partial tear of the Extensor digitorum longus (EDL) muscle along with muscle herniation due to tear in its fascia

Summary

Introduction

A myo-fascial herniation refers to a focal protrusion of the muscle tissue through a defect in its fascia into the overlying subcutaneous tissue. We have not found any published case of acute inversion and plantar flexion ankle injury resulting in a combination of partial tear of the Extensor digitorum longus (EDL) muscle along with muscle herniation due to tear in its fascia. A male, aged 25 years, came with a 2-day history of plantar flexion and inversion injury to the ankle while playing football In his own words, he tripped on the foot of his opponent, lost his balance, and twisted his ankle with a resultant fall on the lateral aspect of his right ankle. MRI of the ankle joint with 3 T was performed 10 days later It revealed a partial tear of the extensor digitorum longus (EDL) muscle in the region of the myo-tendinous junction. The small fascial tear and muscle hernia of the EDL detected accurately on ultrasound could not be confidently detected on the MRI study

Discussion

Findings

Conclusion

Compliance with ethical standards