Fracture Dislocation of Carpometacarpal Joints: A Missed Injury

Abstract

Fracture dislocation of the carpometacarpal joints on the ulnar side of the hand is an uncommon injury. These are high-energy injuries seen in motorcyclists and boxers. The mechanism of injury involves violent, forceful dorsiflexion of the wrist combined with longitudinal impact on the closed hand. This article reports a case of fracture of the base of the middle finger with dislocation of the ring and little finger carpometacarpal joints. On first examination, a diagnosis of isolated, minimally-displaced, middle-metacarpal base fracture was made and deemed suitable for nonoperative management. The hand was splinted in a plaster-of-Paris slab. Later, a true lateral radiograph showed the exact nature of the injury. The fracture was successfully treated with closed reduction under general anesthesia and transfixation using Kirschner wires. Functional results were excellent with return to work at 10 weeks and excellent grip strength at 14 weeks. This injury may be missed in an acute setting in a busy accident and emergency unit. Swelling around the wrist with shortening of the knuckle should alert the clinician towards the possibility of such an injury. On routine anteroposterior view, overlap of joint surfaces, loss of parallelism, and asymmetry at the carpometacarpal joints should raise suspicion of the possibility of a subtle carpometacarpal injury. This article highlights the importance of a high index of suspicion, a true lateral radiograph, and careful evaluation of radiographs in diagnosing these injuries. Intensive postoperative physiotherapy is vital to achieving a satisfactory outcome.

Carpometacarpal Dislocation of the Third to Fifth Fingers and an Associated Fracture of the Hamate in a Military Paratrooper

“…They represent less than 1% of all injuries to the hand and wrist regions [ 3 – 6 ]. Additionally, owing to extensive swelling and overlapping of bones on the radiograph, up to 70% of them are missed or misdiagnosed [ 2 , 7 – 9 ]. These injuries more commonly occur as a result of high-energy trauma as in our case (parachuting accident) while the predominant mechanism is direct force in the axial direction which causes secondary flexion or extension forces.…”

“…Applying a high index of suspicion and performing a good clinical examination play a prominent role in recognizing this rare condition. Treatment is controversial and can be either conservative or operative [1][2][3]. We report a case of acute closed dislocation of the third through fifth carpometacarpal joints and an associated fracture of the hamate in a military paratrooper.…”

Carpometacarpal Fracture-Dislocations: A Retrospective Review of Injury Characteristics and Radiographic Outcomes

“…Given the association with high-energy mechanisms, a thorough evaluation must be performed as these injuries can easily be overlooked. 3,18 In one study, 71% of CMC dislocations were missed in patients seen in an emergency department setting. 3 As described by Henderson and Arafa, 3 swelling may obscure clinical deformity of the dislocated joints, and routine radiographs may not show the displacement.…”

Multiple carpometacarpal dislocations and an associated fracture of the hamate: an uncommon injury

“…CMC dislocations are often seen following high velocity trauma and frequently occur together with multiple or life-threatening injuries 2 4. The CMC joints have a complex anatomical configuration.…”