Recently, three hand surgeons from well-known centers for reconstructive hand surgery presented a lecture on complications following dislocations of the proximal interphalangeal (PIP) joint. This is the joint you are describing. They offered some information about splinting that may be helpful.
First, understanding a little bit about the injury is important. Injuries to the joint in the middle joint of the finger (the proximal interphalangeal (PIP) joint) can be very problematic. When there has been a fracture and/or dislocation, every effort is made to prevent complications such as chronic swelling, stiffness, deformity, and loss of finger function. When the volar plate (restraining ligament) of the joint is damaged by the dislocation, redislocation can occur.
Damage to the cup-shaped joint along with injury to the ligaments can result in an unstable joint. The most successful treatment of these injuries involves limited immobilization with a finger splint and early motion of the finger. Keeping the gliding and sliding motion of the joint is very important — even more so than fixing the dislocation.
Conservative (nonoperative) care is advised when the dislocation is considered “stable”. Stability is determined by X-rays based on how much of the joint surface is damaged (fractured). The surgeon also looks at whether or not the joint partially or completely dislocates during motion. So your next step should be to have an orthopedic surgeon or hand surgeon examine and evaluate your finger.
The use of splinting during the early (acute) phase of healing could be helpful but must be used carefully. A balance is essential between maintaining the joint in a stable position while still allowing motion. The surgeon may recommend using a figure-of-eight splint to keep the finger in slight flexion (bent 10 degrees at the PIP joint). X-rays can be used to show that the joint stays in place while in the splint.
Buddy taping (taping the damaged finger to the finger next to it or between two fingers) is an acceptable alternative. Splinting or taping also immobilizes the distal interphalangeal (DIP) joint (tip of the finger). So it is necessary to take this into consideration in order to prevent stiffness of the finger. An unstable joint with severely damaged volar plate (restraining ligament) and any sign of redislocation is an indication that surgery is needed.