Pediatric Complex Metacarpophalangeal Joint Dislocation of the Index Finger.

Background: Metacarpophalangeal (MCP) joint dislocations are the result of a hyperextension injury. Complex MCP joint dislocations-those that are irreducible to closed maneuvers and require surgical intervention-are considered uncommon, even in the pediatric population. Although several structures have been identified that contribute to irreducible dislocations, the volar plate is the most significant barrier to reduction through interposition into the MCP joint. Key differences that require consideration for MCP joint dislocations in pediatric patients include ligamentous laxity, the absence of sesamoid bones, the possibility for cartilage fractures, and the possibility of growth arrest. Open surgical intervention for a complex MCP joint dislocation is performed through either the volar or dorsal approach. Controversy exists about which approach is superior.

Case Report: We present the case of a 7-year-old female who sustained a complex MCP joint dislocation of the index finger. After numerous unsuccessful attempts at closed reduction, the patient underwent open reduction through the dorsal approach. The phalangeal head had buttonholed through the volar plate and was reduced by using a Freer elevator as a lever and applying gentle traction and flexion. At 4-week follow-up, the patient was pain-free and had regained nearly full range of motion of the index finger MCP joint.

Conclusion: In addition to the classic volar and dorsal approaches, different techniques have been used to reduce complex dislocations in pediatric patients, including arthroscopic surgery, a percutaneous technique with manipulation of a skin hook, and a percutaneous technique with a dorsal incision. As demonstrated in this case, open reduction through the dorsal approach remains a viable treatment option for complex MCP joint dislocations in the pediatric population.