Matthew Bernstein, David M. Kalainov, and Charles Carroll IV

Indications

1. Inadequate closed reduction

a. Epibasal fracture with greater than 30 degrees of angulation

b. Intra-articular fracture with more than 1 to 2 mm of step-off

c. Articular impaction

d. Trapeziometacarpal joint subluxation/dislocation

2. Adequate closed reduction obtained but not maintained by cast immobilization.

3. Open fracture

4. Concomitant soft-tissue injury requiring frequent access to the wound (e.g., burn)

Contraindications

1. Nondisplaced fracture amenable to cast immobilization

2. Poor patient compliance or severe coexisting medical illness

3. Nonfunctional hand (relative)

Preoperative Preparation

1. Standard AP/lateral/oblique plain radiographs of the injured hand

2. True AP and lateral views of the thumb carpo-metacarpal joint

3. Comparative views of the contralateral thumb carpo-metacarpal joint

4. CT or tomograms if the extent of articular damage is difficult to assess with plain X-rays

5. Classify the fracture pattern.

a. Extra-articular epibasal

b. Intra-articular two-part (Bennett’s fracture)

c. Intra-articular three-part (Rolando’s fracture)

d. Intra-articular comminuted

6. Evaluate for concomitant injuries (e.g., tendon rupture, trapezial fracture, metacarpophalangeal joint instability).

7. Document the neurovascular status.

8. Plan the method of fixation: K-wires, interfragmen-tary screws, plate/screws, external fixation.

9. Discuss with the patient the common potential complications associated with operative treatment of thumb metacarpal fractures.

Special Instruments, Position, and Anesthesia

1. Supine position with a hand table extension

2. Upper extremity pneumatic tourniquet; include the forearm in the surgical field

3. Regional or general anesthesia

4. Low-power loop magnification (2.5X)

6. Standard or mini-fluoroscopy unit

7. Powered wire driver and K-wires (0.028-, 0.035-, and 0.045-in)

8. Internal fixation set with 2-mm and 2.7-mm screws and plates (T-shaped and L-shaped); smaller screws for minute articular fragments (1 mm to 1.5 mm)

9. External fixation set if indicated (e.g., Mini External Fixator, Synthes, Paoli, PA)

Tips and Pearls

1. Intravenous antibiotics should be administered prior to tourniquet inflation.

2. Most unstable extra-articular (epibasal) and intraar-ticular two-part (Bennett’s) fractures may be effectively treated by closed reduction and percutaneous pinning.

3. Displaced three-part fractures (Rolando’s) can also be managed by closed reduction and percutaneous pinning. However, open reduction and screw/plate fixation will often permit a more accurate restoration of the joint surface and an earlier return to function. T-shaped and L-shaped plates are ideally suited for these fractures.

4. External fixation is helpful in situations of significant bone loss, comminution, soft-tissue injury, and/or infection. Dynamic skeletal traction through an oblique pin in the thumb metacarpal is an alternative to external fixation.

5. Bone grafting is necessary if the reduced articular surface requires metaphyseal support. An adequate amount of cancellous graft can usually be harvested from the distal radius through a small cortical window.

6. In rare instances of articular cartilage destruction involving both surfaces of the trapeziometacarpal joint, primary arthrodesis may be indicated.

What To Avoid

1. Avoid capturing the thumb flexor and extensor tendons in the fixation.

2. Review the anatomy of the dorsal radial sensory nerve branches. Avoid inadvertent injury with percutaneous pinning and open techniques.

3. Prevent unnecessary stripping of the periosteum and thenar muscles.