Diagnosi e valutazione ecografica della rottura del ventre mediale del muscolo gastrocnemio (“Tennis Leg”)

Purpose: The aim of this study is to demonstrate the diagnostic accuracy of ultrasonography (US) in the diagnosis of rupture of the medial head of the gastrocnemius muscle, also called "tennis leg" (TL). Materials and methods: Thirty-five consecutive patients with acute traumatic injury of the calf underwent US examination. There were 25 men and 10 women; mean age 47.5 years (range 35-60 years). All examinations were performed using a 5-12 MHz broadband electronic linear array probe. Results: Thirty-three out of 35 patients had TL; 24 cases of partial rupture and nine cases of complete rupture were diagnosed. In the remaining two cases, both with symptoms suggesting TL, one patient had a tear of the proximal musculotendinous junction and one had a ruptured Baker's cyst. Fluid collections caused by the muscular rupture were visible as hypoechoic areas; in 80% of cases associated by a hyperechoic oval area due to hematoma and local inflammation. The degree of fluid collection in the patients with complete rupture (6-16 mm; mean: 9.7 mm) was significantly greater than the one seen in patients with partial rupture (4-8 mm; mean: 6.8 mm). Conclusions: US is the imaging modality of choice in clinical suspicion of TL, both in the initial workup of the patient and in the follow-up. US is easy to perform and is particularly useful to distinguish TL from other pathologies, especially ruptured Baker's cyst and deep vein thrombosis, which require a different therapeutic management.