Sonographic visibility of the sinus tarsi with a 12 MHz transducer

Abstract

Objectives To assess the value of ultrasonography in studies of the ligaments within the sinus tarsi (ST) in healthy subjects. Materials and methods We examined 20 healthy volunteers using a 12-MHz transducer with THI and compound imaging. With the foot in inversion, the following structures were examined with coronal and transverse scans: (1) the root of the inferior extensor retinaculum (RIER); (2) the interosseous talocalcaneal ligament (ITCL); (3) the cervical ligament (CL); (4) the bifurcate ligament (BL); (5) the synovial recesses, which were examined for possible distention (distended synovial recesses, DSR). The sonographic features, orientation, and thickness of each ligament were assessed. Results The easiest structure to identify (visualized in 20/20 subjects) was the RIER, which formed a semiarch. The two deeper layers were hypoechoic, the superficial layer hyperechoic. The ITCL was situated posteriorly and deep with an oblique course. It appeared hypoechoic with a mean thickness of 4.06 mm ± 0.7. It was visualized in 18/20 (90 %) subjects. The CL (isoechoic/hyperechoic) was located more anteriorly at an intermediate depth. The orientation was almost vertical. It was visualized in 17/20 (85 %) subjects, with a mean thickness of 2.28 mm ± 0.34. The BL appeared hypoechoic. It was visualized in 19/20 (95 %) subjects with transverse (anterior end of the ST) and longitudinal scans. The calcaneonavicular and calcaneocuboid components displayed mean (SD) thicknesses of 2.09 mm ± 0.37 and 2.7 mm ± 0.32, respectively. The ITCL and RIER were visualized in the same scan as a semiarch. DSR was observed in 4/20 (20 %) subjects. Conclusions The present study shows that, in patients with suspected ST pathology, the anatomic structures that make up this recess can be adequately examined with ultrasonography performed with ordinary 12-MHz transducers.Keywords Musculoskeletal ultrasound Á Sinus tarsi Á Harmonic imaging Á Compound imaging Sommario Obiettivi indagare la capacità degli ultrasuoni (US) di identificare le strutture legamentose del seno del tarso (ST) in un gruppo di soggetti sani. Materiali e Metodi abbiamo studiato 20 volontari sani, utilizzando sonde da 12 MHz, Compound e THI attivati. Sono stati indagati con piede in inversione: (1) 123J Ultrasound (2016) 19:107-113 DOI 10.1007/s40477-014-0145-y retinacolo inferiore degli estensori (RIER) (2) legamento interosseo (ITCL) (3) legamento cervicale (CL) (4) legamento biforcato (BL) (5) eventuali distensioni di recessi sinoviali (DSR), con scansioni coronali e trasversali, valutando ecostruttura, orientamento e spessore dei legamenti. Risultati (1) la RIER, repere ecografico, è stata la struttura di più agevole identificazione: con decorso a semiarco, ipoecogena nei 2 strati profondi, iperecogena in quello superficiale, visualizzata in 20/20 soggetti (2) il ITCL in situazione posteriore e profonda, con andamento obliquo ha presentato spessore medio di 4.06 mm ± 0.7, ipoecogeno, visualizzato in 18/20 (90 %); (3) il CL, più anteriore e orientamento qua...

Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings

“…The sinus tarsi is a laterally flaring fat-filled conical canal located between the talus and calcaneus bones in front of the posterior subtalar joint. It contains several ligaments that contribute to hindfoot stability (62). Peripherally, bands from the extensor retinaculum enter the sinus tarsi.…”

“…Anteriorly, the bifurcate ligament connects the midfoot and hindfoot to its calcaneocuboid and calcaneonavicular bands. Centrally, the talocalcaneal ligaments (interosseous and cervical) stabilize the subtalar articulation by limiting talar flexion and rotation relative to the calcaneus (6,62) (Fig 21). Unstable heel valgus leads to repetitive rotation and translation at the subtalar joint, overloading the sinus tarsi ligaments.…”

“…Sinus tarsi syndrome is difficult to diagnose clinically and shows few radiographic findings. Sonographic assessment is challenging because of the variable depth and orientation of the ligaments and surrounding adipose tissue (62). Alterations of fat signal intensity at MRI are the hallmark of sinus tarsi syndrome (56,63) (Fig 22).…”

Ultrasound Imaging Guide for Assessment of the Intrinsic Ligaments Stabilizing the Subtalar and Midtarsal Joints

“…The sinus tarsi and tarsal canal are located between the posterior STj and the TCNj. [27][28][29] The sinus looks like a cylindric or cone-shaped space filled with adipose and loose connective tissue. It contains small arteries and veins, nerve endings, synovial recesses, important ligaments, and extensions of the inferior extensor retinaculum (InER) that stabilize the subtalar articular complex during walking.…”

“…Using a lateral scanning approach with the probe placed at the most posterior part of the sinus tarsi, some authors describe the InOL as a vertical oblique hypoechoic band occupying the deep posteromedial portion of the fossa. 27 A medial approach could also be suggested to evaluate the InOL by placing the probe vertically over the tarsal canal, just posterior to the sustentaculum tali, while applying a valgus (eversion) stress to the foot to widen the joint space (►Fig. 3a).…”