Dorsal joint dislocations occur as a result of axial loading on the joint with associated hyperextension. Once skeletal maturity is reached, dorsal PIP joint dislocations in which the middle phalanx displaces dorsally on the proximal phalanx are the most common skeletal hand injury. They generally occur on the little finger (26%) and the ring finger (22%). Dorsal DIP joint dislocations typically occur via traumatic injury or sports and frequently have associated soft tissue injury and/or fractures. They frequently occur secondary to flexor digitorum profundus avulsion fractures, commonly known as a Jersey finger.
Volar dislocations occur as dorsal, medial, and lateral forces strain the collateral ligaments and volar plate. Volar dislocations are rarer, but lack of prompt treatment can lead to entrapment of the proximal phalangeal condyle. MCP joint dislocations commonly occur due to hyperextension of the joint with subsequent rupture of the volar plate. This injury is more likely to occur at the thumb because of the increased joint mobility. Even seemingly minor joint dislocations can lead to long-term pain, joint dysfunction, and adhesion development, so they must be managed carefully.
Prevalence: An estimated 35 000 finger dislocations occur annually. Black patients have a significantly elevated risk of finger dislocation compared to White and Hispanic populations, with an incidence ratio of 2.17 and 3.42, respectively.
- Age – The median age of injury is 21 years, with over 40% of all finger dislocations occurring in patients aged 10-19 years. Nearly 70% of these injuries are related to sports or other recreational activities.
- Sex / gender – Over 75% of cases occur in male patients.
