It has been shown to produce similar results as MRI in diagnosing ankle tendon tears, although US results are more dependent on operator skill and expertise [10,35]. In this case, it is assumed that the procedure is performed and interpreted by an expert. One study showed that it had a sensitivity of 100% and an accuracy of 93% compared to surgical findings [36]. With regard to the tibialis posterior tendon, one study evaluating tendon pathology showed that US was slightly less sensitive than MRI; however, this difference did not significantly affect clinical management [37]. One study using US showed 100% sensitivity and 90% accuracy in diagnosing peroneal tendon tears [38]; suggesting that US may be more useful than MRI. With regard to chronic Achilles tendinopathy, US detected 21 of 26 cases of tendinosis and partial rupture [39], and another study showed that US can differentiate full- thickness from partial-thickness Achilles tears with 92% accuracy [40]. In addition to the diagnostic capabilities of US, when a tendon abnormality is detected, it can be used to guide interventions such as concurrent performance of US-guided intrasheath anesthetic injections [11]. It can also be used for direct intratendinous biologic injection and dry needling [41-43]. One significant advantage of US is in the dynamic assessment for tendon subluxation (including intrasheath subluxation) and dislocation, with a reported positive predictive value of 100% compared to surgical findings [44,45]. US-guided sheath injections are more accurate than palpation guided and allow for precise positioning of the needle tip in the sheath rather than the tendon substance because a large volume intratendinous injection of corticosteroids or local anesthetic can result in a split tear [46]. US can detect intratendinous tophi in gout, enthesitis of the Achilles tendon or plantar fascia in spondyloarthritis, and tenosynovitis in spondyloarthritis and rheumatoid arthritis [47].
Chronic Ankle Pain. It has been shown to produce similar results as MRI in diagnosing ankle tendon tears, although US results are more dependent on operator skill and expertise [10,35]. In this case, it is assumed that the procedure is performed and interpreted by an expert. One study showed that it had a sensitivity of 100% and an accuracy of 93% compared to surgical findings [36]. With regard to the tibialis posterior tendon, one study evaluating tendon pathology showed that US was slightly less sensitive than MRI; however, this difference did not significantly affect clinical management [37]. One study using US showed 100% sensitivity and 90% accuracy in diagnosing peroneal tendon tears [38]; suggesting that US may be more useful than MRI. With regard to chronic Achilles tendinopathy, US detected 21 of 26 cases of tendinosis and partial rupture [39], and another study showed that US can differentiate full- thickness from partial-thickness Achilles tears with 92% accuracy [40]. In addition to the diagnostic capabilities of US, when a tendon abnormality is detected, it can be used to guide interventions such as concurrent performance of US-guided intrasheath anesthetic injections [11]. It can also be used for direct intratendinous biologic injection and dry needling [41-43]. One significant advantage of US is in the dynamic assessment for tendon subluxation (including intrasheath subluxation) and dislocation, with a reported positive predictive value of 100% compared to surgical findings [44,45]. US-guided sheath injections are more accurate than palpation guided and allow for precise positioning of the needle tip in the sheath rather than the tendon substance because a large volume intratendinous injection of corticosteroids or local anesthetic can result in a split tear [46]. US can detect intratendinous tophi in gout, enthesitis of the Achilles tendon or plantar fascia in spondyloarthritis, and tenosynovitis in spondyloarthritis and rheumatoid arthritis [47].