PMC7079263_01
Initial radiograph showing the proximal displacement of the fourth and fifth metacarpal bones. (a) Posteroanterior view. (b) Oblique semisupinated view.
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CMC joint dislocation was made by radiography (Figures 1(a) and 1(b)). Closed reduction was not successful, and he was referred to our clinic on the day after the injury.
CT scan showing the carpometacarpal bases incarcerated at the fracture gap of the hamate hook at the fracture site. (a) Axial view. (b) Sagittal view. (c) Three-dimensional view of the hand. (d) Coronal view of the CT scan also shows the avulsion fracture between the base of the fourth and fifth metacarpal bones.
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Computed tomography (CT) revealed a fracture of the hamate hook associated with volar ulnar dislocation of the fourth and fifth CMC joint, and the base of the dislocated metacarpal was incarcerated between the hook and body of the hamate (Figures 2(a)-2(c)). An avulsion fracture was noted between the base of the fourth and fifth metacarpal bones (Figure 2(d)).
Intraoperative findings.
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The fracture site of the hamate hook was located using a longitudinal incision of the palmar carpal ligament (Figure 3).
Intraoperative CT scan (sagittal view) showing the anatomical reduction of the hamate hook.
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Therefore, to examine the reduction of the fracture, we used intraoperative CT after provisional fixation of the fracture site (Figure 4).
Postoperative radiograph. (a) Posteroanterior view. (b) Oblique semisupinated view.
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The fourth and fifth CMC joint were temporally fixed percutaneously from the metacarpal bones to the carpal bones, respectively, using 1.5 mm Kirschner wires (K-wires; Figures 5(a) and 5(b)).
Postoperative CT scan showing the reduction and appropriate placement of the screw.
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Reduction and appropriate placement of the screw were confirmed postoperatively using CT (Figure 6).
Radiographs after the removal of the K-wires showing the maintenance of the reduction of CMC joint. (a) Posteroanterior view. (b) Oblique semisupinated view.
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A radiograph demonstrated the maintenance of the reduction after the removal of the K-wires (Figures 7(a) and 7(b)).
CT scan performed 3 months postoperatively showing the gap at the fracture site.
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Three months after the operation, CT revealed a gap of the fracture site at the hamate hook (Figure 8).
Radiograph 2 years after the surgery. (a) Posteroanterior view. (b) Oblique semisupinated view.
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Hand score was 0. He had no signs of rupture or irritation of the flexor digitorum profundus (Figure 9).