The anatomical study of proximal interphalangeal joint volar plate and its clinical significance

Abstract

Objective To study the anatomy of the volar plate and ligaments of the proximal interphalangeal (PIP) joint and explore the etiology and treatment of PIP joint flexion contracture. Methods Sixteen fresh cadaver finger specimens were dissected. The anatomy and movement relationship of the volar plate and ligaments of the PIP joint were observed in 8 specimens. The other 8 specimens were used for simulation to cut different ligaments and observe movement of the volar plate, and analysis the real function of each ligament. Results In finger flexion the bottom of the middle phalanx pushed the volar plate to the proximal side. The distal ligament of the volar plate was the main force to pull the volar plate back in place during finger extensor. The two Check-Rein ligaments almost had no effect to the movement of the volar plate. The two collateral ligaments restricted the volar plate on the trochlea of the phalanx, and moderately influenced the movement of the volar plate. The collateral ligament was the main mechanism to maintain stability of the proximal interphalangeal joint. Conclusion When the distal volar plate is injured, contracture of the collateral ligament fixes the volar plate in subluxation. Restoring flexibility of the collateral ligament is the key to treating flexion contracture of the proximal interphalangeal joint. Key words: Anatomy; Finger joint; Volar plate; Joint contracture