Correct answer to Q1 is: Large fluid collection between the gastrocnemius and soleus muscles

Correct answer to Q2 is: Tear of the myotendinous junction of the left gastrocnemius muscle

Discussion

US demonstrated fluid deep to the medial gastrocnemius and superficial to the soleus muscle, most prominent at the level of the myotendinous junction and distal region of the medial gastrocnemius muscle. Calf muscle tear injury, also known as “tennis leg”, is a relatively common clinical condition involving damage to the medial head of the gastrocnemius muscle. A tear in the distal gastrocnemius and myotendinous junction may be seen as a disruption in contour and echogenicity of muscle fibers, often seen along a nearby fluid collection representing hematoma (the echogenicity of this fluid may vary depending the time from the trauma).

Muscle tears located in the calf region are often associated with other pathologies such as Achilles tendinosis making the correct diagnosis difficult. The physical exam and diagnostic US add up to the final diagnosis and provide useful information for treatment [1].

Conclusion

“Tennis leg”, a lesion in the myotendinous region of the medial gastrocnemius muscle, should be considered in patients complaining of a an acute and sharp pain in the region of the triceps surae often involving a sudden, subjective “snapping” sensation. Ultrasound examination provides information of lesion location and the presence of hematoma.

Conflicts of Interest:

“The authors declare no conflict of interest.”

References

1. Pedret C, Balius R, Blasi M, Dávila F, Aramendi JF, Masci L, de la Fuente J. Ultrasound classification of medial gastrocnemious injuries. Scand J Med Sci Sports. 2020 Dec;30(12):2456-2465. doi: 10.1111/sms.13812. Epub 2020 Sep 16. PMID: 32854168.