The purposes of our educational exhibit are to: 1.Review the clinically relevant anatomy and high-resolution ultrasonography (HRUS) appearances of extensor digitorum tendons (EDT) of the finger; 2.Describe the dynamic manoeuvres to assess the integrity of EDT; 3.Illustrate the typical EDT tears and show correlation with sonographic imaging.
The extensor digitorum communis tendons are the primary extensors of the digits; their muscle originates from the lateral epicondyle of the humerus and lies centrally in the dorsal forearm.
Over the wrist,
the tendons pass through the 4th compartment formed by the extensor retinaculum and radius,
after which they fan out towards the digits,
passing over the carpal bones toward the metacarpophalangeal (MCP) joints [1,2]. Distal to the MCP joint,
each extensor tendon splits into a central...
Findings and procedure details
Injuries at the MCP joint are often open and occur with the joint in flexion with laceration of extensor tendon  (Fig.5,
Fig.6). The disruption of the central slip causes the “boutounniere deformity” that is a pathologic flexion at the PIP joint with hyperextension at DIP joint.
The most common mechanism of injury is a direct trauma or a forced flexion of an actively extended PIP joint (Fig.7). Injuries at the DIP joint may disrupt the terminal extensor tendon,
which is dorsally and...
The recent development of high-resolution transducers has made HRUS an excellent technique to study anatomy,
diagnose diseases and allow a dynamic assessment of the finger.
Scuola di Specializzazione Radiodiagnostica Università diGenova (firstname.lastname@example.org) M.Marino,
Institute of Radiology,
School of Medicine,
Scuola di Specializzazione Radiodiagnostica Università di Genova A.Fischetti,
Scuola di Specializzazione Radiodiagnostica Università diGenova A.Muda,
Ospedale IRCCS San Martino IST,
Clavero JA; GolanóP,
Esplugas M.Extensormechanismof thefingers:MRimaging-anatomiccorrelation.
23(3): 593-611(2003). Chen K,
Gonzalez MH and Mohan V.
Extensors of the Hand.
Curr Orthop Pract,
24(2):189-196 (2013). Hollinshead WH.
Anatomy for Surgeons: The Back and Limbs.
PA: Harper & Row (1982). Bianchi S,
Ultrasound of the Musculoskeletal System.
Springer (2007). Schöffl V,
Tendon injuries of the...