Foot and Ankle 2023, Jan, 11 | 12:00 am

Traditional Triple Arthrodesis

DEFINITION

Triple arthrodesis is a procedure performed to restore and maintain physiologic hindfoot alignment. It is typically reserved for the following:

Severe fixed deformity not amenable to joint-sparing procedures Inflammatory arthropathy of the hindfoot

ANATOMY

The hindfoot comprises the talus, calcaneus, navicular, and cuboid.

Physiologic alignment is generally defined as a congruent talar-first metatarsal alignment in both the anteroposterior (AP) and lateral planes with weight bearing.

The talar-calcaneal articulation is referred to as the subtalar joint.

The combination of the talonavicular and calcaneocuboid articulations is known as the transverse tarsal joint.

Multiple ligamentous static restraints support the hindfoot. In fact, in stance phase, the physiologically normal foot is balanced and plantigrade without any dynamic muscle forces acting on it.

Physiologic hindfoot alignment is influenced by the ankle, midfoot, and forefoot.

The hindfoot is a component of the ankle-hindfoot complex. To an extent, ankle malalignment can be compensated by the hindfoot.

The foot is balanced when there is relatively even pressure distribution on the heel, first metatarsal-sesamoid complex, and the fifth metatarsal (ie, a plantigrade foot).

Physiologically normal hindfoot alignment can be distorted by ankle, midfoot, and forefoot deformity.

Although the ankle is primarily responsible for dorsiflexion and plantarflexion, the hindfoot has some capacity to compensate in the sagittal plane with ankle stiffness, as evidenced by residual dorsiflexion and plantarflexion following ankle arthrodesis.

Ambulation

With transition from heel strike to stance phase, the hindfoot becomes accommodative to the surface it contacts by “unlocking” the hindfoot joints.

With push-off, the posterior tibial tendon (PTT) inverts the hindfoot, thereby locking the transverse tarsal joints and hindfoot.

This converts the foot's accommodative function to one of biomechanical advantage with creation of a rigid lever arm for the Achilles tendon.

PATHOGENESIS AND NATURAL HISTORY

Hindfoot alignment is easily distorted by imbalance of its dynamic stabilizers, in particular, the posterior tibial and

peroneal tendons.

If the imbalance persists and becomes chronic, the hindfoot's static ligamentous restraints may weaken, creating a hindfoot deformity that ultimately may become fixed.

PTT dysfunction leads to a flatfoot deformity with attenuation of the medial static restraints (spring ligament complex, medial talonavicular capsule) and pes planovalgus (flatfoot) deformity.

Peroneal tendon dysfunction may lead to lateral anklehindfoot attenuation and a pes cavovarus (hindfoot varus) deformity.

Posttraumatic or inflammatory arthritis may also create a stiff and painful hindfoot, with or without deformity.

PATIENT HISTORY AND PHYSICAL FINDINGS

The patient typically describes aching in the hindfoot, particularly in the sinus tarsi area, with weight bearing. There may be a report of a progressive deformity.

Stiffness and swelling are common complaints.

It is important to elicit a history of an inflammatory arthropathy. A neurologic and vascular examination is required.

The patient should be examined while standing and ambulating.

The deformity may not be obvious with the patient nonweight bearing.

Typically, the patient will walk with a limp.

A single limb heel rise for a patient with pes planovalgus deformity, if possible, will determine if the deformity is flexible and if the PTT is functional.

With the patient seated, range of motion (ROM) is assessed.

Inversion and eversion are almost always restricted in patients being considered for triple arthrodesis.

The talus can be stabilized with a thumb on the talar neck to determine dorsiflexion and plantarflexion in the hindfoot.

Ankle ROM and stability also should be evaluated.

An equinus contracture may be present and is important when considering surgery. Achilles tendon lengthening may be required to reposition the hindfoot anatomically. Many hindfoot deformities result in Achilles tendon contractures.

IMAGING AND OTHER DIAGNOSTIC STUDIES

Plain radiographs of the weight-bearing foot in the AP, lateral, and oblique views (FIG 1)

Occasionally, contralateral foot radiographs are useful in understanding what is physiologically normal for an individual.

FIG 1 • Weightbearing radiographs of patient with PTT dysfunction and fixed hindfoot deformity. A. AP view demonstrates forefoot abduction and talonavicular joint uncovering (note divergence of talar and first metatarsal longitudinal axes, rather than the congruence/paralellism seen in patients without PTT dysfunction). B. Lateral view. Note the severe talonavicular sag (suggestive of spring ligament attenuation/incompetence).

I routinely obtain ipsilateral ankle radiographs as well. In severe deformity, there may be a preexisting talar tilt.

If this is the case, proper operative realignment of the hindfoot may be compromised by the more proximal deformity.

One needs to be aware of preexisting talar tilt or ankle malalignment to ensure that the hindfoot deformity is corrected appropriately.

I will check the ankle alignment fluoroscopically while realigning the hindfoot in surgery.

Rarely is computed tomography or magnetic resonance imaging necessary.

NONOPERATIVE MANAGEMENT

Activity modification

Nonsteroidal anti-inflammatory agents Corticosteroid injection

Bracing

Lace-up brace

Hinged or fixed ankle-foot orthosis

SURGICAL MANAGEMENT

A spectrum of pathologies may warrant triple arthrodesis:

Stage III posterior tibial tendinopathy Chronic peroneal tendinopathy Posttraumatic hindfoot arthritis Inflammatory arthritis

Charcot neuroarthropathy Chronic spring ligament rupture

If a joint-sparing procedure can be performed, it should be favored over triple arthrodesis. Selective hindfoot arthrodesis may also be considered.

There has been a trend toward double arthrodesis in lieu of triple arthrodesis.

The concept is to preserve the accommodative effect of the calcaneocuboid joint when possible and only perform talonavicular and subtalar joint arthrodeses.

Isolated talonavicular joint arthrodesis restricts hindfoot motion by 90%.

Preoperative Planning

The preoperative deformity needs to be assessed to determine what correction is warranted.

If there is a severe pes planovalgus deformity, consider a single-incision medial approach double arthrodesis to eliminate the risk of lateral wound problems that may occur with a lateral approach in such deformity.

Equinus contracture: It may be necessary to lengthen the Achilles tendon to correct the deformity. Equipment

Fluoroscopy unit to confirm reduction and hardware placement Preferred screw (and plating or staple) system

Bone graft is not required but may be useful to fill any voids or gaps with deformity correction.

Positioning

With a traditional triple arthrodesis, the patient is placed on the operating table in a modified lateral decubitus position (“sloppy lateral position”; FIG 2). This allows access to the lateral and medial hindfoot.

FIG 2 • The patient is placed on a beanbag in a modified lateral position that allows access to the medial and lateral foot. A stack of folded sheets is placed under foot to be operated.

The patient's torso is supported with a beanbag. An axillary roll is usually indicated.

The contralateral hip is flexed slightly to make room for a stack of folded sheets on which the operative leg is placed.

The opposite leg must be padded if it contacts the beanbag.

I routinely use a thigh tourniquet if I am considering an Achilles tendon lengthening.

If an Achilles tendon lengthening is unnecessary, a calf tourniquet is adequate.

Approach

The traditional utilitarian lateral approach uses a 7- to 8-cm incision from the tip of the fibula toward the base of the fourth metatarsal.

The traditional utilitarian dorsomedial approach uses a 7- to 8-cm incision from the anterior aspect of the anterior medial malleolus toward the dorsomedial base of the first metatarsal.

If equinus contracture is present, I first perform an Achilles tendon lengthening.

TECHNIQUES

Lateral Exposure

Create a lateral longitudinal incision (TECH FIG 1A).

Protect the sural nerve (TECH FIG 1B).

Create the interval between the peroneal tendons and the extensor digitorum brevis (EDB) muscle. Elevate the EDB muscle with its fascia dorsally (TECH FIG 1C).

Avoid “shredding” the muscle and fascia, as it will be used as the deep layer closure at the completion of the surgery.

TECH FIG 1 • A. Standard lateral approach. B. Protect the sural nerve. C. Elevate the EDB muscle and fascia. D. Expose the subtalar joint. A blunt retractor may be placed deep to the calcaneofibular ligament.

E. Identify the calcaneocuboid joint. In this patient with an inflammatory arthropathy, the joint is distorted.

(continued)

Release the bifurcate (calcaneonavicular and calcaneocuboid) ligament that lies deep to the EDB muscle. Release the calcaneocuboid capsule also (TECH FIG 1D).

Place a blunt retractor between the lateral subtalar joint and the calcaneofibular ligament (TECH FIG 1E). Use a distractor to expose the subtalar joint first (TECH FIG 1F,G) and then the calcaneocuboid joint.

The lateral talonavicular joint may also be accessed through this approach.

TECH FIG 1 • (continued) F,G. Subtalar joint exposed with a distraction device.

Subtalar, Calcaneocuboid, and Lateral Talonavicular Joint Preparation

The preparation is the same for all three joints.

Remove residual articular cartilage with a sharp elevator or chisel (TECH FIG 2A). Preserve the native subchondral bone architecture.

TECH FIG 2 • A. Chisel being used to remove residual cartilage. B,C. Preparing the subtalar joint. B. Drill being introduced. C. The reamings created will serve as bone graft. D,E. Preparing the calcaneocuboid joint. D. Chisel being used to remove residual cartilage. (continued)

Drill or chisel (“feather”) the subchondral bone to allow for vascular channels to form at the arthrodesis

surfaces while maintaining subchondral bone architecture (TECH FIG 2B,C).

For the subtalar joint, include not only the posterior facet but also the middle and anterior facets.

However, be careful to not disrupt the delicate vasculature on the undersurface of the talar neck, if possible.

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TECH FIG 2 • (continued) E. Drilling the subchondral bone to promote fusion and adding reamings that serve as bone graft. F,G. Exposure of the lateral talonavicular joint.

The calcaneocuboid joint is a “saddle” joint, so avoid simply driving a chisel directly across the joint surfaces as it may result in more than desired bone removal, particularly when correcting pes planovalgus (TECH FIG 2D,E).

The lateral talonavicular joint is often difficult to reach from the medial approach, but the lateral exposure affords satisfactory access to prepare this aspect of the talonavicular joint (TECH FIG 2F,G).

I irrigate the joint before drilling the subchondral bone. Drilling creates reamings that serve as bone graft, and I do not want to wash the reamings away.
Medial Exposure

Create a longitudinal incision (TECH FIG 3A).

Cauterize connecting branches of the saphenous vein so the vein can be mobilized. Identify the tibialis anterior tendon and protect it throughout the procedure (TECH FIG 3B).

Typically, fibers of the extensor retinaculum must be released to access the tibialis anterior tendon.

TECH FIG 3 • A,B. Medial approach to the talonavicular joint. (continued)

Perform a longitudinal capsulotomy (TECH FIG 3C,D).

The spring ligament may need to be divided, and the PTT tendon may need to be released from the navicular to improve access to the talonavicular joint.

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TECH FIG 3 • (continued) C. Medial exposure after capsulotomy. D. Close-up demonstrating erosive changes in the talonavicular joint in a patient with an inflammatory arthropathy.
Talonavicular Joint Preparation

Use a distractor to gain full exposure to the talonavicular joint (TECH FIG 4A,B).

In brittle bone, be careful when applying pressure to the navicular as it may fracture.

Remove the residual articular cartilage from the talonavicular joint (TECH FIG 4C).

In pes planovalgus deformity, the talar head may be weak, so be careful not to gouge the talar head when attempting to delaminate the residual articular cartilage.

The lateral talar head should have already been prepared from the lateral approach. Remove cartilage from the navicular.

TECH FIG 4 • A. Talonavicular joint distracted. B. Débriding the joint with a rongeur. C. A chisel is used to remove residual articular cartilage. D. Drilling the subchondral bone to promote fusion.

Penetrate the subchondral bone to promote fusion.

The talus is relatively easy to access with a small-diameter drill bit (TECH FIG 4D). Be careful using a chisel on the talar head as it may fracture.

The navicular can also be readily drilled.

I do not often use a burr to prepare subchondral bone for fusion, but on the navicular, it is sometimes very effective, provided cold water or saline irrigation is used simultaneously to limit bone necrosis. However, this may wash away desirable reamings that could serve as bone graft.

As for the preparation of the other joint surfaces, I irrigate the talonavicular joint before drilling then try to maintain the reamings so they can be used as bone graft.

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Hindfoot Reduction

Place bone graft in the arthrodesis sites at this time, before the reduction is performed.

I routinely use bone graft to fill voids at the surfaces to be fused. Although this is not mandatory, I believe that filling the voids enhances the body's ability to form bridging trabeculations.

The calcaneus must be centered properly under the talus.

Through the lateral wound, the optimal relationship of the posterior facet can be assessed and controlled (TECH FIG 5A,B).

Physiologically, there is a gap between the anterolateral talus and the anterior calcaneal process, and this should be recreated.

In correcting severe pes planovalgus, I aim to overcorrect the calcaneus beneath the talus (TECH FIG 5C).

TECH FIG 5 • Reducing the hindfoot. A,B. Checking the subtalar joint reduction. C. The hindfoot is maintained in the corrected position. Lateral (D) and mortise (E) fluoroscopic views after a guide pin was placed across the reduced subtalar joint. F. Reduction of talonavicular joint. G. Guide pins placed across talonavicular joint.

Once the optimal subtalar relationship established, I provisionally pin the subtalar joint.

I use a guide pin for the intended cannulated screw and try to place the pin in the intended trajectory for the screw (TECH FIG 5D,E).

Typically, I have an assistant working with me, so I hold the reduction while the assistant places the guide pin from the calcaneal tuberosity into the talar body.

The dual-incision approach affords the surgeon the ability to palpate the talonavicular and calcaneocuboid joint reductions simultaneously.

With the subtalar joint reduced, I then attempt to reduce the talonavicular joint to an anatomic position. I can palpate both sides of the talonavicular joint by having two incisions (TECH FIG 5F).

When correcting pes planovalgus deformity, I err on the side of overcorrection of the navicular on the

talar head.

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Once I have the talonavicular joint reduced, I protect the tibialis anterior tendon and have my assistant drive two guide pins, appropriately spaced from one another, from the navicular into the talar head (TECH FIG 5G).

I attempt to place the screw from the most distal aspect of the navicular, even reaming the medial wall of the first cuneiform slightly, so the pin needs to be flush against the medial aspect of the first cuneiform.

Finally, I provisionally pin the calcaneocuboid joint.

To create a relief area on the anterior process of the calcaneus for the screw insertion, I remove a small wedge of bone from the anterior process using a rongeur.

I routinely push up on the cuboid and down on the anterior process of the calcaneus to reduce the joint.

Despite the lateral approach, optimal longitudinal orientation of the guide pin across the calcaneocuboid joint is not possible.

I sometimes create a stab incision behind the peroneal tendons; dissect carefully deep to the sural nerve and tendons, creating a soft tissue tunnel; insert a drill sleeve; and then deliver the guide pin safely to the anterior process of the talus.

The guide pin is driven across the joint.
Hindfoot Stabilization

The reduction and the position of the guide pins are checked fluoroscopically (TECH FIG 6A).

Adjustments are made as necessary.

At this stage, I also routinely check the ankle fluoroscopically to be sure there is no ankle deformity that may distort the true hindfoot alignment.

I determine proper screws lengths and overdrill the guide pins but only to the initial aspect of the second bone.

Most modern screws are self-drilling and self-tapping; however, particularly in the navicular, I prefer to predrill to diminish the risk of navicular fracture.

TECH FIG 6 • A. Fluoroscopic confirmation of the guide pins placed across the talonavicular joint (this patient had undergone prior midfoot arthrodesis). B,C. Clinical and fluoroscopic views of the subtalar screw in place. D-F. Clinical and fluoroscopic views of the talonavicular screws in place. One partially threaded compression screw is placed first, and one fully threaded positional screw is placed second. (continued)

By not drilling the full length of the planned screw, purchase of the screw is typically improved.

I first place the subtalar screw as a compression screw (TECH FIG 6B,C). Next, I place the two talonavicular screws (TECH FIG 6D-F).

The first screw is a compression screw.

I use a positional screw for the second screw.

If greater talonavicular stability is needed, I create a small dorsal incision over the midfoot; protect the superficial peroneal nerve, extensor tendons, and the deep neurovascular bundle; and using a drill sleeve, place a guide pin from the centrolateral navicular into the talar body or sometimes through the inferior talar body and into the

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calcaneus. Over this, I place a third talonavicular screw, either positional or compression; although with two screws medially, further compression is generally not possible.

TECH FIG 6 • (continued) G,H. Calcaneocuboid screw. A separate stab incision is made with a carefully prepared soft tissue tunnel under the sural nerve and peroneal tendons. Note thumb pressure pushing up on the cuboid to maintain joint reduction and a more favorable position of the cuboid. I,J. Final AP and lateral fluoroscopic views confirming appropriate reduction, bony apposition at the arthrodesis sites, and proper hardware position.

For the calcaneocuboid joint, I protect the soft tissues and overdrill only the anterior calcaneal process. Then I insert a compression or positional screw across the calcaneocuboid joint (TECH FIG 6G,H).

If the joint is well reduced, I tend to use a positional screw; if the joint could stand to be compressed for better bony apposition, however, I place a compression screw.

As mentioned earlier, I push up on the cuboid and down on the anterior calcaneal process to maintain the reduction and to make sure the cuboid does not sag, occasionally leaving it prominent postoperatively. However, with an anatomic reduction, this is rarely an issue.

Occasionally, I add a lateral compression plate or staple across the calcaneocuboid joint to augment the fixation.

I get final fluoroscopic confirmation of alignment, bony apposition at the arthrodesis sites, and hardware position (TECH FIG 6I,J).
Closure

I routinely pack bone graft at the “quadruple arthrodesis” site, where talus, calcaneus, navicular, and cuboid meet at the lateral aspect of the talonavicular joint (TECH FIG 7).

Medially, the capsule is reapproximated.

Laterally, the fascia overlying the EDB muscle can usually be reapproximated to soft tissues adjacent to the peroneal tendons.

Any bone graft in the soft tissues is irrigated away, as it may interfere with wound healing. Next, the subcutaneous tissues are closed.

The skin incisions are then reapproximated to tensionless closures.

I routinely release the tourniquet prior to subcutaneous layer closure. I also routinely use a lateral drain.

The stab incisions for screw placement are closed.

Sterile dressings and a posterior or sugar-tong splint are placed over adequate padding, with the ankle in neutral position.

TECH FIG 7 • Bone grafting the confluence of all four hindfoot bones at the “quadruple arthrodesis” site.

PEARLS AND PITFALLS

Achilles ▪ If an equinus contracture is not corrected, anatomic reduction will be difficult or tendon impossible.

Severe pes ▪ This is perhaps more safely corrected with a single-incision medial approach planovalgus double arthrodesis. A traditional dual-incision triple arthrodesis may lead to a lateral deformity wound complication when correcting severe flatfoot deformity.

Ankle ▪ In severe deformity, be sure to check the ankle preoperatively. With preexisting ankle deformity, a triple arthrodesis is sure to fail.

Sequence of ▪ Although the talonavicular joint may be reduced first, the most important reduction correction of deformity, in my opinion, is the centering of the calcaneus

anatomically under the talus.

Talonavicular ▪ If a traditional dual-incision triple arthrodesis is performed, use the lateral access joint to prepare the lateral talonavicular joint because it is difficult to reach the lateral preparation talar head from the medial approach.

POSTOPERATIVE CARE

I routinely keep patients overnight for pain control, nasal oxygen (which may improve wound healing), and limb elevation.

Although I recognize that some of my colleagues perform this surgery as a pure outpatient procedure, I believe that one night (which still qualifies as an outpatient procedure) is in the patient's best interest after major hindfoot surgery.

The patient wears a splint for 2 weeks.

The patient returns to the clinic at 2 weeks for suture removal and short-leg cast.

The patient returns to the clinic at 6 weeks after surgery for radiographs out of cast and repeat casting. Touchdown weight bearing is the rule for a full 10 weeks.

The patient returns to the clinic at 10 weeks, and if repeat simulated weight-bearing radiographs suggest healing and no complications, he or she can be placed in a cam boot with gradual progression to full weight bearing by 12 to 14 weeks.

The patient returns to the clinic at 14 to 16 weeks for full weight-bearing radiographs (FIG 3), then gradual progression to full activities.

OUTCOMES

Patients are generally improved with an appropriately performed triple arthrodesis.

At intermediate to long-term follow-up, patients are functional in their activities of daily living but few are able to perform demanding recreational activities.

With time, patients tend to develop adjacent joint arthritis, but it is unclear if this causes functional deficits.

“Triple arthrodesis” performed through a single medial incision and including only the subtalar and talonavicular joints is gradually displacing the traditional triple arthrodesis. Results of this procedure are promising, but it is not clear if they are more favorable than those of the traditional triple arthrodesis.

COMPLICATIONS

Nonunion Malunion

Wound dehiscence

Infection

Sural neuralgia Prominent hardware

Persistent pain despite appropriate management and satisfactory clinical and radiographic findings

FIG 3 • Follow-up weight-bearing radiographs of the patient with fixed hindfoot deformity secondary to PTT dysfunction and spring ligament tear. Note the congruent alignment of the talar-first metatarsal axis in both the AP and lateral views.

Traditional Triple Arthrodesis

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Traditional Triple Arthrodesis

DEFINITION

ANATOMY

PATHOGENESIS AND NATURAL HISTORY

PATIENT HISTORY AND PHYSICAL FINDINGS

IMAGING AND OTHER DIAGNOSTIC STUDIES

NONOPERATIVE MANAGEMENT

SURGICAL MANAGEMENT

Preoperative Planning

Positioning

Approach

TECHNIQUES

Lateral Exposure

Subtalar, Calcaneocuboid, and Lateral Talonavicular Joint Preparation

Medial Exposure

Talonavicular Joint Preparation

Hindfoot Reduction

Hindfoot Stabilization

Closure

POSTOPERATIVE CARE

OUTCOMES

COMPLICATIONS

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