Volar plate injury encompasses a spectrum of multilayered condensation of fibrocartilaginous soft tissue and bony injury lying between the flexor tendons and the palmar PIPJ capsule at the PIPJ that causes injury when the athlete misses a frisbee throw or a basketball pass because these activities forced hyperextension of the PIP joint proximal interphalangeal joint extension or flexion, combined with active range of motion exercises, crush injury, axial loading, direct blunt or penetrating trauma, fingers struck by a ball, adversely impact grasping, dorsal dislocation, fine-motor movements, and tear the volar plate away from its insertion, troublesome snapping, as the extensor lateral bands slide dorsally on the condyles of the P1 epiphysis. Volar plate maintains the stability of the PIPJ in the anteroposterior plane and prevents PIPJ hyperextension. It originates from the proximal phalanx (P1) and inserts onto the P2.
Anatomy
The PIPJ is a synovial hinge type joint, allowing flexion and extension (ranging = 0° to 100°-110°). The volar plate basically maintains the stability of the PIPJ in the anteroposterior plane, axial loading, and prevents PIPJ hyperextension. It originates from the proximal phalanx of the hand and is inserted onto the middle phalanx. At its proximal origin, it has extensions is called checkrein ligaments, which attach to the periosteum of the proximal phalanx by connecting to the distal end of the A2 pulley. The other collateral ligaments (ulnar and radial) also contribute to the stability of the PIPJ.[rx]
Volar plate rupture occurs basically distally, at the weaker fusion with the middle phalanx, whereas the proximal stronger checkrein ligaments merely/rarely rupture. Volar plate injury can occur with an avulsion fracture, most commonly at the volar base of the middle phalanx. Subluxation, dislocation, laceration of the PIPJ may also occur. Contrary to volar plate instability, central slip disruption causes the PIPJ to drop into flexion and, when untreated, can result in a boutonnière deformity in a later time.
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.[rx] 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.[rx]
Classification systems of volar plate injuries
| Eaton classification of volar plate injuries | |
| Type 1 | Avulsion of the volar plate without a fracture or dislocation |
| Type 2 | Complete dorsal dislocation without fracture and avulsion of the volar plate |
| Type 3a | Fracture-dislocation with <40% PIPJ surface with dorsal portion of the collateral ligaments remaining attached to the middle phalanx (stable) |
| Type 3b | Fracture-dislocation with >40% PIPJ surface with little or no ligament remaining attached to the middle phalanx (unstable) |
| Keifhaber-Stern classification of volar plate injuries (modification of Hastings classification) | |
| Stable | Avulsion fracture involving <30% articular base of the middle phalanx |
| Tenuous | Avulsion fracture involving 30%-50% articular base of the middle phalanx; reduces with <30° of flexion |
| Unstable | Avulsion fracture involving <50% articular base of the middle phalanx but requires >30° flexion to maintain reduction |
Symptoms
Signs and symptoms include significant swelling, tenderness, or deformity at the joint, pain when the finger is resting, inability to move the joint fully, severe pain at motion, or rotational, flexion, extension movement.
Treatment
The surgical aim for correction of post-traumatic chronic injuries includes the full restoration of joint stability, functional movement improvement, pain with swelling, tenderness relief, and return to full sports or work. Surgical options may include different methods such as direct volar plate repair if still achievable and widely followed technique, volar plate reconstruction surgery with tendon or artificial graft, collateral ligament advancement, lateral band translocation, and Flexor Digitalis superficialis (FDS) stenosis is the most popular treatment technique.
References
