Simultaneous Central Slip and Volar Plate Injuries at PIP Joint: A Novel Therapeutic Approach

Abstract

In hands, both the proximal (PIPJ) and distal (DIPJ) interphalangeal joints are bound by collateral ligaments on the radial and ulnar sides, extensor tendons like the central slip dorsally, and a ligamentous volar plate on their palmar surface. 1 These structures all contribute to PIPJ stability and movement; so injury to any of them can cause significant joint instability and, untreated, chronic finger deformity. 2 Extensor tendon injuries generally are more common and functionally limiting than flexor tendon injuries. [2][3][4] Nonetheless, nondisplaced, noncomminuted finger fractures usually are treated nonsurgically. 5 Volar plate fractures and central slip injuries typically occur secondary to entirely different mechanisms, the former typically caused by PIPJ hyperextension, a crush injury, or axial loading (eg, someone "jams" their finger). The joint becomes unstable and is at risk of further subluxation. Such injuries are more common in youths, often attributed to sports. 6 Untreated, a swan-neck deformity can result. Typical management of nondisplaced volar plate fractures involves extension-block splinting, 7 in which the PIPJ is usually held in some degree of flexion to facilitate volar-plate healing and prevent hyperextension. Conversely, central slip injuries are caused by hyperflexion, or from direct blunt or penetrating trauma, typically to the middle phalanx. 7 Contrary to volar plate instability, central slip disruption causes the PIPJ to drop into flexion and, when untreated, can result in a boutonnière deformity.Although both injuries are common, it is highly infrequent to find them simultaneously in the same joint. 8 Despite protocols existing for each of these injuries occurring separately, 6,9 no protocol yet exists guiding management