Image Interpretation: There is a moderate amount of fluid in the retrocalcaneal bursa. The bursal tissue is hypertrophic with hyperemia noted on color doppler. The achilles tendon is intact with normal echotexture.
Teaching Pearl: It is important to float the probe (especially in long axis) in order to get the best image quality. A neutral or slightly dorsiflexed ankle can help in maintaining probe contact. Ultrasound of the hindfoot can identify common pathology including retrocalcaneal bursitis, achilles tendinosis, achilles rupture, or posterior ankle impingement. Ultrasound should be used to assist with needle guidance for procedures in order to minimize the risk of adverse events. If injecting lateral to medial, the sural nerve needs to be identified prior to needle placement.
Maffulli N, Sharma P, Luscombe KL. Achilles tendinopathy: aetiology and management. J R Soc Med. 2004 Oct;97(10):472-6. doi: 10.1177/0141076809701004. PMID: 15459257; PMCID: PMC1079614.
Turmo-Garuz A, Rodas G, Balius R, Til L, Miguel-Perez M, Pedret C, Del Buono A, Maffulli N. Can local corticosteroid injection in the retrocalcaneal bursa lead to rupture of the Achilles tendon and the medial head of the gastrocnemius muscle? Musculoskelet Surg. 2014 Aug;98(2):121-6. doi: 10.1007/s12306-013-0305-9. Epub 2013 Nov 13. PMID: 24222527.