Palmar Dislocation Fracture of the Hamate: A Case Report and Review of Literature.

Hamate dislocations are rare lesions of the carpus, which make their diagnosis difficult or even missed, and their management non-standardized.  We report the case of a 34-year-old victim of a high kinetic traffic accident. The initial evaluation revealed multiple fractures of both upper limbs, including a palmar fracture dislocation fracture of the hamate, without any vascular or nerve complications. Open surgical treatment via a dorsal approach allowed reduction and fixation of the hamate by temporary multiple pinning. At 12-month follow-up the patient had pain free motion of the wrist with a DASH score of 3. Radiographs showed evidence of proximal pole hamate sclerosis and carpo-metacarpal narrowing.  Owing to its rarity, literature on this topic is extremity limited. Various mechanisms have been described to explain these injuries, including dorsal pressure on the carpus associated with traction of the annular carpal ligament on its hamate insertion. Symptoms can be minimal and only three cases of nerve complications have been reported. Long-term outcomes following these injuries usually result in decrease in wrist motion and grip strength.  The rarity of dislocations with or without hamate fracture favors the absence or the delay of diagnosis, which must lead to a precise radiographic analysis and to the implementation of a CT scan in case of high kinetics carpal trauma, even if it is poorly symptomatic.  Level 5, case study.