David M. Kalainov and Franklin Chen

Indications

1. Inadequate closed reduction

a. Head: greater than 1 mm to 2 mm articular step-off, collateral ligament avulsion fracture with more than 2 mm displacement, malrotation

b. Neck (Boxer’s Fracture): greater than 50 degrees apex dorsal angulation (relative), palmar prominence of the metacarpal head, malrotation

c. Shaft: greater than 20 to 30 degrees apex dorsal angulation, more than 3 to 4 mm shortening, less than 50% bone apposition, malrotation

d. Base: greater than 1 to 2 mm articular step-off, carpometacarpal joint subluxation/dislocation, malrotation

2. Adequate closed reduction obtained but not maintained by cast, splint, or functional brace

3. Open fracture

4. Comminuted fracture (relative)

5. Segmental bone loss

6. Multiple metacarpal fractures (relative)

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

8. Tendon repair necessitating early metacarpophalangeal joint motion (relative)

Contraindications

1. Stable, reduced fracture

2. Patient noncompliance or severe coexisting medical illness

3. Nonfunctional hand (relative)

Preoperative Preparation

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

2. Special imaging studies

a. Brewerton view—head fractures

b. CT or tomograms—articular injuries

3. Characterize the fracture

a. Location: head, neck, shaft, base

b. Pattern of injury: transverse, oblique, spiral, comminuted, segmental bone loss

c. Degree and direction of displacement

d. Stability

e. Soft-tissue integrity

4. Document the neurovascular status and evaluate the extremity for associated trauma.

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

Special Instruments, Position, and Anesthesia

1. Supine position with a hand table extension

2. Upper arm pneumatic tourniquet set at 250 mm Hg

3. Regional or general anesthesia

4. Low-power loop magnification (2.5×)

5. Basic hand tray and routiné orthopedic instruments (e.g., tissue scissors, retractors, dental probe, sharp pointed reduction clamp, periosteal elevator, Freer elevator, curettes, osteotomes, mallet)

6. Standard or mini-fluoroscopy unit

7. Powered wire driver and K-wires (0.028 to 0.062 in)

8. Internal fixation set with 2-mm and 2.7-mm screws and plates (one quarter tubular, DCP, T-shaped, L-shaped, mini condylar); smaller screws for articular injuries (1.0 to 1.5 mm)

9. 26-gauge malleable wire, external fixation set, and mini suture anchors if indicated

Tips and Pearls

1. Intravenous antibiotics are best administered prior to tourniquet inflation.

2. Open fractures should be thoroughly cleaned prior to stabilizing.

3. Several techniques of fracture fixation are possible; the simplest method requiring the least amount of soft-tissue disruption is preferred.

4. When placing K-wires percutaneously, insert the tip by hand against bone and confirm the position under image intensification. Attach the powered wire driver as a second step. This lends more control than positioning the pin and wire driver together as a unit.

5. K-wires should cross either proximal or distal to the fracture site. Wires crossing at the level of the fracture may lead to distraction and interfere with bone healing.

6. Basic principles of lag screw fixation are important when stabilizing spiral and long oblique shaft fractures with interfragmentary screws.

a. The fracture length should be at least twice the diameter of the metacarpal shaft to accommodate two or more screws.

b. Each screw should be positioned at least two thread diameters away from the nearest cortical margin and directed along a plane that bisects both the fracture line and longitudinal axis of the metacarpal.

c. Prominent screw heads should be countersunk.

7. A plate can be applied in a neutralizing, bridging, buttress, or compression mode. If a T-shaped or L-shaped plate is selected, fix the proximal portion of the plate to bone before the straight portion to avoid creating a rotational deformity.

8. Consider early bone grafting and soft-tissue coverage for fractures with significant bone loss and soft-tissue destruction.

9. Small amounts of cancellous bone graft can be harvested from the distal radius. Larger quantities of cancellous graft and corticocancellous structural graft can be obtained from the anterior iliac crest.

10. Clinically assess the fracture reduction after adequate stabilization and before all wires/screws are placed.

a. Passively flex and extend the wrist. The tenodesis effect will lead to partial finger extension when the wrist is flexed and to partial finger flexion when the wrist is extended. The small finger should remain well-aligned with the ring finger without overlap and all finger tips should point toward the scaphoid tubercle in flexion.