Authors of section

Authors

Khairul Faizi Mohammad, Brad Yoo

Executive Editors

Markku T Nousiainen, Richard Buckley

Open all credits

Arthrodesis of length stable proximal articular fractures of the 1st–4th metatarsal

1. General considerations

If fragmentation is such that the joint cannot be reconstructed, the options are:

  • Nonoperative treatment
  • Primary fusion

None of these options are ideal.

The results may be unsatisfactory because of the fracture’s intraarticular nature, and the patient may complain of pain and stiffness.

As fusion is permanent, the decision to perform fusion should be considered for only significantly damaged articular surfaces.

Note on illustrations - To illustrate this procedure, a fractured 1st metatarsal is shown. The principles and the step-wise procedure are identical for the second and third metatarsals.

Soft-tissue injury

These fractures can have a severe associated soft-tissue injury.

Hardware selection

The fixation can be ensured using lag screws, staples, or a plate.

Typically, lag screws and staples are used when the construct is length stable and compression is possible.

Arthrodesis of a TMT joint with screws, staples, or a plate

Plates are an acceptable alternative to lag screws but result in more prominent hardware. A dorsal plate is less prominent than a medially placed plate (first metatarsal).

Arthrodesis of a TMT joint with a plate

2. Temporizing measures

Medial and lateral external fixation (with a distractor device to restore columnar length) may be applied as soon as possible to stabilize the foot and decrease further injury to the soft tissues.

Percutaneous K-wires can be used to reduce displaced fragments and left as temporary fixation.

Medial- and lateral-column distractor applied to improve visualization of a length stable proximal 1st metatarsal fracture

3. Approach

Selection of approach

Fractures of the first metatarsal can be approached through a medial or a dorsal approach:

Any single metatarsal injury in metatarsals 2–3 can be approached through the following dorsal approach:

Visualization

A medial-column distractor may be used to restore the length of the medial column.

If the medial distraction creates an abduction deformity, applying a lateral distractor may help minimize the angulation.

It is helpful to have comparative x-rays from the uninjured side, allowing proper length and morphology to be judged.

The proximal pin is inserted into the neck of the talus through a stab incision. Image intensification can be used to ensure correct pin placement outside the articular surfaces. The correct insertion point is often located 1–2 cm posterior to the navicular tubercle.

The distal pin is inserted in the first metatarsal.

Medial- and lateral-column distractor applied to improve visualization of a length stable proximal 1st metatarsal fracture

4. Irrigation and debridement

Irrigate the fracture site using a syringe.

Irrigation of a proximal articular fracture of the 1st metatarsal

Displaced fracture fragments are debrided and mobilized with a dental pick or Freer elevator.

Once adequate visualization has been achieved and the joint thoroughly irrigated, examine the extent of articular surface involvement to validate the preoperative plan of primary fusion versus ORIF.

If joint fragmentation is not extensive and tarsometatarsal instability is absent, it may be possible to perform fixation.

Debridement of a proximal articular fracture of the 1st metatarsal

5. Preparation of joint for fusion

Preparation of joint for fusion

Remove the cartilage on both sides using a curette.

Cartilage removal of the adjacent bone for arthrodesis of the 1st TMT joint

Penetrate the subchondral bone using a high-speed burr to promote bone growth.

Promoting bone growth by penetrating the subchondral bone for arthrodesis of the 1st TMT joint

The application of bone graft, allograft, or bone substitute may be required to fill a small gap in such a length-stable situation.

Application of bone graft for arthrodesis of the TMT joint of the 1st metatarsal

6. Temporary fixation

Compress the arthrodesis site and secure the compression with K-wires.

Temporary fixation for arthrodesis of the TMT joint of the 1st metatarsal

7. Lag screw fixation

Fixation

Ideally, two 3.5 lag screws are inserted. One comes from the distodorsal to proximal plantar. One comes from proximal dorsal to distal plantar.

It is often difficult to insert more than one screw in the 2nd and 3rd metatarsal.

Lag screw fixation for arthrodesis of the TMT joint of the 1st metatarsal

Countersinking

Countersink the glide hole to reduce screw prominence.

The metatarsal base requires significant bone removal to allow for proper screw insertion. In this case, a high-speed burr is recommended.

Countersinking for lag screw fixation of the TMT joint of the 1st metatarsal

The screws should fully engage the bone proximally but should not be prominent at the plantar surface of the cuneiform as this may cause pain.

Lag screw fixation for arthrodesis of the TMT joint of the 1st metatarsal

8. Staple fixation

Staple placement

For the first metatarsal, insert one staple medially and one dorsally.

Due to lack of space, one staple is frequently used for the second and third TMT joints.

Staple fixation for arthrodesis of the TMT joint of the 1st metatarsal

Drilling

Use the manufacturer's drill guide to prepare a hole on each side of the arthrodesis site. The depth of the hole should correspond to the length of the staple legs.

Drilling for staple fixation of the TMT joint of the 1st metatarsal

Staple insertion

Use the manufacturer's device to align the tips of the implant legs parallel with the drill holes and insert the staple.

Use an appropriate tamp to seat the staple fully.

Staple fixation for arthrodesis of the TMT joint of the 1st metatarsal

9. Compression plating

Compression plate fixation

Contour a T-plate to fit the bone surface.

A 3.5 mm plate can be used for the first TMT joint, allowing three-screw fixation in the distal and proximal segments.

For the second and third TMT joint, a 2.7 mm T-plate can be used, which allows for two screws in the proximal and three screws in the distal segment.

Plate contouring for arthrodesis of a TMT joint
Screw insertion

Insert screws in compression mode after appropriate length, alignment, and rotation have been verified.

Arthrodesis of a TMT joint with a plate
Go to diagnosis