Middle aged woman with a popping sound and pain in left calf while exercising
- MR leg was performed
FINDINGS:
- MR LEG WITHOUT IV CONTRAST
- A. Sagittal PDFS image shows characteristic oblique significant fluid between the soleus muscle and the medial head of the gastrocnemius muscles
- B.
- Axial PDFS image shows severe edema, fluid between the soleus muscle and the medial head of the gastrocnemius muscles (thick arrow).
- Irregular low signal intensity fibers within the fluid represents the remnant of the ruptured plantaris tendon ( thin arrow).
- Mild edema within the medial head of the gastrocnemius muscle, compatible with interstitial muscle tearing.
DIAGNOSIS:
- ‘Tennis leg’ with rupture of plantaris muscle and strain of medial head of gastrocnemius.
DISCUSSION:
- Tennis leg represents a myofascial or tendinous injury of the lower limb and, not surprisingly, is seen most frequently in tennis players.
Epidemiology:
- Although classically seen in people who play tennis, it can also be induced by playing squash, skiing, and athletics. Therefore, it typically occurs in active individuals, more frequently in middle-aged individuals. The same injury can also occur with more sedate activities, such as running to catch a bus. Extension of the knee and forced dorsiflexion of the ankle seem to be the most frequent biomechanical causes of the injury
Clinical presentation:
- Sudden sharp pain in the posterior aspect of the calf, with a sensation of something 'snapping' within the calf.
- This is associated with focal tenderness and swelling, which can substantial.
- A focal gap can sometimes be felt early on (i.e. prior to swelling) at the site of the tear.
Pathology:
- Though tennis leg is classically caused by rupture of the plantaris muscle, the term is also used more generally and may refer to a strain of the medial head of the gastrocnemius muscle or the soleus muscle
Ultrasound:
- Fluid deep to medial gastrocnemius and superficial to the soleus muscle, most prominent at the level of the myotendinous junction.
- A tear in the deep surface of gastrocnemius may be seen as a disruption in contour and echogenicity of muscle fibers.
- A torn plantaris tendon may also be identified.
MRI:
- High T2 signal fluid deep to medial gastrocnemius and superficial to the soleus.
- A focal disruption of muscle continuity along the deep aspect of the medial head of the gastrocnemius, with associated muscle edema.
- The plantaris tendon may either be torn or intact.
Treatment and prognosis:
- Treatment is usually conservative and the condition self-limiting. Only in cases where severe swelling leads to compartment syndrome is surgical fasciotomy necessary.
Dr. DHINESHKUMAR T
Radiology resident
Manipal hospital, Yeshwanthpur, Bengaluru.
Dr DEEPTI H V
Senior Consultant Radiologist
Manipal hospital, Yeshwanthpur, Bengaluru.
