Minimally Invasive Realignment Surgery of the Charcot Foot

The aftereffects of Charcot joint disease include joint subluxation or dislocation, loss of bone quality, and osseous malalignment (FIG 1).

As a result of the deformed Charcot foot position, aberrant weight-bearing forces and altered muscle–tendon balance increase the risk for ulceration, infection, and amputation.

When treating the Charcot neuropathic foot, the best results are achieved when intervention is initiated as early as possible.

In acute Charcot neuroarthropathy, the goal of treatment is to stabilize the foot. Total contact casting is the traditional treatment.

In this patient population, it is extremely difficult to maintain non–weight-bearing status for multiple reasons, including muscle atrophy, obesity, and diminished proprioception.

Non–weight-bearing immobilization for months produces osteopenia of the involved foot and increased weight-bearing forces on the contralateral limb.

The sequelae can make it difficult for subsequent surgery on the involved foot and can lead to ulceration and Charcot neuroarthropathy in the contralateral foot.

In chronic Charcot neuroarthropathy, the goal of treatment is to realign the soft tissue and osseous structures. In general, surgeries are aimed at realignment, but in these extremely deformed feet, acute realignment is challenging.

Traditionally, acute realignment procedures such as Achilles tendon lengthening, ostectomy, débridement, osteotomy, arthrodesis, and open reduction with internal fixation (plantar plating) have been attempted.

Acute correction via open reduction with application of static external fixation has also been reported.

More recently, internal fixation methods have been augmented or replaced by external fixation as a means of static fixation of a Charcot reconstruction.

Here, we present a new two-stage minimally invasive gradual correction method with the use of external fixation for acute and chronic Charcot reconstruction, which was developed by the senior author (D.P.).

Gradual deformity correction with external fixation is preferred for large-deformity reductions of the dislocated Charcot joints of the foot. Correction with external fixation allows for gradual, accurate realignment of the dislocated or subluxated Charcot joints.

SURGICAL TREATMENT

The goals of surgical intervention for the Charcot foot are to restore anatomic alignment, impart stability, prevent amputation, prevent foot shortening, and allow the patient to be ambulatory.

Historically, open reduction with internal fixation was the mainstay for treatment of Charcot foot deformities.

Large open incisions were made to remove the excess bone, reduce the dislocated bone, and stabilize with internal fixation (screw fixation or plantar plating).

These invasive surgical procedures typically resulted in shortening of the foot or incomplete deformity reduction and occasionally resulted in neurovascular compromise, incision healing problems, infection, and the use of non–weight-bearing casts and boots.

In cases of tarsometatarsal Charcot deformity, open reduction is advantageous.

Typically, Charcot neuroarthropathy of the tarsometatarsal joints is associated with mild to moderate deformities because the tarsometatarsal joints are structurally interlocked.

Acute realignment is achieved by performing a wedge resection or open reduction with fusion and internal fixation to produce a stable foot.

In acute Charcot neuroarthropathy, a static external fixation is placed to stabilize the Charcot process. The smooth wire fixation for the external fixation is applied to avoid the “hot,” or Charcot, joint region of the foot.

The static fixator is applied strategically so gradual realignment can begin after the acute phase of Charcot has passed. Thus, the external fixator serves a dual purpose by stabilizing both the acute Charcot joint and the subsequent realignment of the dislocated osseous anatomy.

Once the bony anatomy is realigned, the external fixation is removed and a formal minimally invasive fusion of the Charcot joint is performed. Rigid intramedullary metatarsal screws are used to maintain the fusion.

Chronic stable or coalesced Charcot foot deformities require an osteotomy for correction of the deformity. We prefer a percutaneous Gigli saw osteotomy technique.

Midfoot osteotomies can be performed across three levels (ie, talar neck and calcaneal neck, cubonavicular osseous level, and cuneocuboid osseous level).

Performing Gigli saw osteotomy across multiple metatarsals should be avoided because of the neurovascular injury.

For an unstable or an incompletely coalesced Charcot foot, correction can be obtained through gradual distraction.

Despite the radiographic appearance of coalescence (superimposition of the dislocated or fragmented pedal bone due to the Charcot process), most Charcot deformities can undergo distraction without osteotomy to realign the pedal anatomy.

An Achilles tendon lengthening is performed and held in a neutral position with the external fixation. This restores the normal calcaneal pitch and hindfoot position.

Then, under fluoroscopy, acute forefoot reduction is attempted and, if possible, fixation with intermedullary metatarsal screws is carried out.

Acute reduction of the forefoot is rarely successful. If the forefoot cannot be acutely reduced, an external fixator is used to hold the hindfoot position while the forefoot is lengthened and realigned.

APPROACH

This first stage of the procedure consists of osseous realignment of the forefoot on a fixed hindfoot, which is achieved with an external fixator using distraction.

After realignment, the correction is maintained by minimally invasive arthrodesis of the Charcot joint and is fixed with percutaneous intramedullary metatarsal screws.