Anatomical considerations of the thumb carpo-metacarpal joint ligaments, based on a case report of isolated joint dislocation

Abstract

Background: Trapeziometacarpal joint (TM joint) dislocation is an uncommon lesion, mentioned primarily in isolated case reports. Various treatment modalities are used, including conservative and surgical options; however no gold standard approach exists for this rare injury. We present such a case, and review the current literature concepts about the anatomy of the TM joint and its stabilizing ligament. Case Report: We report a case of a patient presenting an acute TM joint dislocation, handled with closed reduction maneuvers under regional block anesthesia and a splint for 6 weeks. With complete full recovery of thumb function. Discussion: Isolated dislocation of the TM joint is a rare lesion in the hand, caused by an injury to the ligament stabilizers. An complete understanding of the anatomy is necessary to make a correct diagnosis and treatment. Despite this, there are differences between different authors about which ligaments have a greater function in the stability of the joint. Since Bettinger's description, it was maintained that the main stabilizer of this joint whas the palmar oblique ligament, known by the name of beak ligament. Conclusion: We believe that according to the current evidence the DRL, or a dorsal root ligament complex, is the main stabilizer of the TM joint, although findings are not conclusive. Understanding the anatomy of the region is important for comprehending the physiopathology of this rare dislocation, and avoids misconceptions of widely established anatomical concepts in the different literature. What will be essential for surgical treatment?