Acute trauma of the extensor hood of the metacarpophalangeal joint: MR imaging evaluation.

Abstract

MR imaging is accurate for determination of the presence and severity of injury to the extensor hood.

Functional anatomy of the dorsal hood or the hand: correlation of ultrasound and MR findings with cadaveric dissection

“…Although there are many publications about MR studies of the anatomy of the MCP joint [1][2][3][4][5], publications on ultrasound studies of anatomy are relatively scarce [6,7]. None of these studies focus on anatomic correlation with cadaveric specimens.…”

“…The dorsal hood (DH) is a retinacular system [1][2][3][4]6] that stabilizes the extensor tendon at the dorsum of the metacarpophalangeal joint (MCP) keeping the tendon in place during flexion and extension. The DH is made up of three retinacular structures: the sagittal, oblique, and transverse bands.…”

“…The sagittal band supports the extensor tendon at the MCP level; it restricts proximal displacement of the extensor tendon and contributes to the extension of the digit [1,2,11,12]. The sagittal band is mainly made up of compact fibers that are perpendicular to the extensor tendon (Fig.…”

“…1, 4, and 5). During flexion and extension of the MCP joint, the extensor tendon glides longitudinally over the joint stabilized both ulnarly and radially by the dorsal hood [14] The injury of the MCP (knuckle injury) with dorsal hood injury is relatively frequent [11,[15][16][17][18][19] but the dislocation of the extensor tendon is relatively uncommon [1,2,14,[20][21][22].…”

“…c Sagittal ultrasound of the same finger at the proximal phalanx (P1) level: the transverse (TB) and oblique fibers (OB) of the DH appear as a thin hypoechoic band (white arrows) oedema in the surrounding soft tissues on T2-weighted images [1][2][3][4].…”