Pure Isolated Dorsal Hamatometacarpal Dislocation in a Rider: A Case Report and Review of Literature

INTRODUCTION: Pure isolated dislocations of the fifth carpometacarpal joint are extremely rare. To the best of our knowledge, the case, we present here, is among the extremely rare cases report of an unstable hamatometacarpal dislocation(HMD)injury successfully treated by a well-molded cast. CASE REPORT: A 30-year-old rider fell from his horse, causing swelling of the wrist and the fifth finger was rotated with minimal active motion. The radiological assessment (X-rays and tomography) showed a pure HMD. Under sedation, we performed reduction of the dislocation. However, the reduction was lost at the slightest movement requiring a K-wirefixation. The patient refused the surgical treatment and requested non-operative treatment. Thus, while the joint was held in a reduced position, a well-molded plaster cast was applied which immobilized both the hamatometacarpal joint and the metacarpophalangeal joint. Later, the patient was reviewed weekly until 6 weeks, then the cast was removed altogether and the digits were mobilized. At the follow-up of 6 months, he had regained full range of motion of the little finger with no pain, no recurrence of dislocation and returned to his previous level of sporting activity. CONCLUSION: The early detection with careful clinical assessment and radiological analysis for subtle signs, followed by appropriate treatment usually leads to an excellent result.