Certified Hand Therapist (CHT) Practice Exam

A volar PIP dislocation typically results in damage to which structures?

1. Extensor tendons and flexor tendons

2. Collateral ligaments and central slip

3. Joint capsule and dorsal ligaments

4. Volar plate and articular cartilage

The correct answer is: Collateral ligaments and central slip

A volar proximal interphalangeal (PIP) dislocation is characterized by the dorsal displacement of the proximal phalanx relative to the middle phalanx. This type of injury often results in significant stretching and tearing of specific structures around the joint. The most commonly affected structures in a volar PIP dislocation include the collateral ligaments and the central slip. The collateral ligaments, which stabilize the joint laterally, are put under strain during dislocation due to the abnormal positioning of the bones. As the joint dislocates, these ligaments may stretch excessively or even tear, leading to instability. The central slip is part of the extensor mechanism, helping to maintain the extension of the middle phalanx. In a volar dislocation, this structure can be injured as well, resulting in potential difficulties with finger extension and leading to complications like a boutonniere deformity if not treated properly. The damage to these structures is critical to understand for effective management and rehabilitation following a PIP dislocation, emphasizing the importance of prompt assessment and intervention to restore proper joint function.