Edwin W. Ryerson first described triple arthrodesis in 1923 as a fusion of the talocalcaneal, talonavicular, and calcaneal cuboid joints.¹ The goal was to create a well-aligned, plantigrade, and stable foot for patients with deformity or progressive neurologic and arthritic conditions. This procedure should be reserved for instances when all conservative measures have been tried and failed, and a more limited surgical procedure will not afford appropriate pain relief and reduction of the deformity. In cases of a flexible deformity, consideration should first be given to those procedures that are joint sparing, such as tendon transfers or osteotomies.

The following is a list of indications for triple arthrodesis:

Fig. 1 Posttraumatic arthritis. Lateral view radiograph. Patient is status after calcaneocuboid fracture. Degenerative hindfoot arthritis is noted.

Contraindications for triple arthrodesis include any clinical situation that could be treated with a more limited fusion. It is important to isolate the affected joints. Initially this may be done through clinical examination and imaging evaluation. Alternatively, the affected joints may be isolated through the use of intra-articular lidocaine injections. Patients with peripheral vascular disease and blood supply inadequate for healing following surgery should not undergo the procedure. Preoperative evaluation by a vascular specialist is always advised when there is any question as to the patient’s ability to heal. It is also not advisable to perform a triple arthrodesis on patients with neuroarthropathy or with systemic healing issues.

Advanced age and diabetes mellitus are not direct contraindications for triple arthrodesis, although it has implications for the postoperative care regimen.³ Proper control of blood sugar is necessary to allow an optimal postoperative course.

Evaluation of the foot in both standing and resting positions is imperative to patient evaluation. Usually, a varus hindfoot has a compensatory forefoot valgus with a plantarflexed first ray. In this case, additional procedures may be necessary to bring the foot in a plantigrade position following the triple arthrodesis. Claw toes may be present as well. Underlying neuromuscular disorders such as Charcot-Marie-Tooth disease or spinal lesions can cause a cavus foot type.

The hindfoot and forefoot are linked because they compensate for one another. A valgus hindfoot usually compensates with forefoot varus deformity and an abducted forefoot. This compensation is usually centralized around the Chopart joint. For this reason, there is little need for more distal surgery because much can be corrected simply with a triple arthrodesis. Sometimes in valgus foot the Achilles tendon becomes contracted. The Achilles tendon is shortened and calcaneus is laterally deviated. In such cases, the patient also has limited dorsiflexion of the ankle joint. If there is a rigid hindfoot deformity, it may not be possible to evaluate for contracture of the Achilles tendon before surgery. In instances such as this, evaluation of the need for either an Achilles tendon lengthening or gastrocnemius recession must be made during surgery.

Neutral foot weight bearing has 5° of hindfoot valgus. The flatfoot in the non–weight-bearing position has 5° of hindfoot valgus, but it compensates in weight bearing and has 17° of hindfoot valgus. The cavus foot in the non–weight-bearing position has 5° of hindfoot valgus, but in the weight-bearing position it compensates with 17° of hindfoot valgus.

The position of the foot with a respect to the entire lower extremity must be evaluated when preoperatively planning for triple arthrodesis.

The angle of the tibial mechanical axis and its relation to the forefoot should be considered. The tibial mechanical axis has 3 basic forms:

Preoperative valgus mechanical alignment and preoperative varus tibial alignment have an effect on the ultimate position of the foot after triple arthrodesis. Even if the tibial malalignment is not corrected, foot malalignment can be avoided, because the foot has been placed in a plantigrade position with respect to the preexisting proximal lower alignment. This concept comes into play when a patient is to undergo later correction of deformity at the knee joint, because the foot has already been placed in a plantigrade position relative to the original deformity of the tibial mechanical axis. Therefore, in cases such as this, the patient may require revision for correct alignment of the hindfoot.³

A thorough history and examination is critical in providing a diagnosis and outlining indications that will determine the direction of the operative procedure. It is important to review the anticipated outcome of the procedure with the patient so that a realistic goal can be met by both the patient and surgeon. The patient must understand that the time to recovery from this procedure, even with an optimal outcome, is long and challenging, and must not be taken lightly. Patients should be evaluated in a standing position to establish whether the foot is in a plantigrade position to determine the need for correction of angular relationships. The foot should also be evaluated in a non–weight-bearing position to evaluate range of motion and stability. Any osseous prominences or callosities should be noted. Observing the patient’s gait can allow the surgeon to observe functional derangements that are causing symptoms. The inability to perform a single limb heel rise facilitates the diagnosis of posterior tibial tendon dysfunction. Severe hindfoot valgus is observed when excessive abduction of the forefoot produces a too-many-toes” sign. Radiographs of both the foot and ankle should be evaluated.

Evaluation of disorders at the knee joint must be taken into consideration. Patients with longstanding planovalgus deformity also present with lateral knee discomfort and arthritic changes. It is suggested that the patient address the knee deformity before undergoing correction of the foot so that the foot may be positioned plantigrade to the leg.

Ankle joint disorders and degeneration must be taken into consideration when preoperatively planning. A patient who displays both ankle and rearfoot joint degeneration may benefit more from a pantalar arthrodesis. Typically, this is performed in a staged process.

All patients should have weight-bearing radiographs of their feet and ankles: anteroposterior foot, lateral foot, and anteroposterior ankle views. Oblique foot and a mortise view may be taken as well to facilitate preoperative evaluation. Talar head uncovering is seen on anteroposterior view in patients with planovalgus deformity (Fig. 2). These patients also display divergence of the talocalcaneal angle on both the anteroposterior and lateral views. Conversely, these angles tend to be parallel or converge in patients with cavus foot type. The anteroposterior view of the ankle can be used to evaluate any degenerative joint disease, talar tilt, or to visualize calcaneal fibular impingement that is seen with flatfoot deformity.⁵

Fig. 2 Anterior posterior view flatfoot. Talar head uncovering may be visualized. Note the divergence of the talocalcaneal angle.

Other advanced imaging studies such as computed tomography, bone scanning, and magnetic resonance imaging are generally not required for preoperative evaluation. Advanced imaging may prove useful if there is suspicion of avascular necrosis of bone, or in instances in which posttraumatic primary arthrodesis in conjunction with open reduction and internal fixation is being undertaken. If there is a question of infection to bone, this may be confirmed with advanced imaging; however, arthrodesis should not be performed when there is active infection.

Preferably a tourniquet is placed around the upper calf region. Generous soft roll underpadding is placed around the undersurface of the tourniquet, particularly surrounding the course of the peroneal nerve as it wraps around the fibular head to impart adequate protection. This technique allows for the use of lower cuff pressures, typically around 250 mm Hg, compared with higher thigh tourniquets. Standard lower extremity surgical prep and draping may be used. The toes and forefoot may be covered using a surgical glove or iodine adhesive plastic to prevent contamination from debris from the toenails. Appropriate preoperative antibiotic therapy is advocated.³

Proper incisional placement is a key to allowing for sufficient anatomic exposure and ultimately proper reduction of the deformity. The 2-incisional approach is most commonly used; however, alternative single-incisional approaches may be used but do not impart the same degree of exposure.

The lateral incision allows for exposure the subtalar, sinus tarsi, calcaneal cuboid, and lateral talonavicular joint articulations. The incision begins 1 cm distal to the tip of the lateral malleolus, extends along the lateral margin of the floor of the sinus tarsi, and ends along the base of the fourth metatarsal. Correct placement of this incisional line is parallel and between the course of the intermediate dorsal cutaneous and sural nerves. Occasionally, a communicating branch between these 2 nerves may be seen, and may be carefully resected if it will be traumatized during surgery.

Lateral dissection is typically initiated first. The peroneal tendons should be identified running along the lateral inferior aspect of the calcaneus and calcaneal cuboid articulation and retracted inferiorly. Next, the extensor digitorum brevis muscle belly is identified. The deep fascial, capsular, and periosteal tissues overlying the subtalar and calcaneal cuboid joint are opened simultaneously as 1 layer through and inverted-L–shaped flap. The flap is then reflected distally. There may be a large venous plexus along the distal extent of the extensor digitorum brevis muscle belly, so care should be taken to achieve proper hemostasis to prevent possible postoperative complications. The sinus tarsi may now be visualized (Fig. 3). The contents of the sinus tarsi are evacuated by using a hand rongeur or by placing a #15 blade along the osseous constraints of the talus and calcaneus and carefully moving the blade in a circular fashion. Care should be taken that all intertarsal ligaments are removed to allow the calcaneus to be reduced from its valgus position. Visualization of the posterior facet of the subtalar joint can now be made through the void in the sinus tarsi. A lamina spreader is then placed within the subtalar joint to allow wider exposure (Fig. 4).

Fig. 3 Lateral surgical exposure. Note the peroneal tendon coursing below the calcaneocuboid joint. The extensor digitorum brevis belly is reflected distally. The sinus tarsi is visualized centrally. The subtalar plug (Hoke tonsil) may now be evacuated.

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Soft Tissue Closure of Severe Diabetic Foot Infections: A Combination of Biologics, Negative Pressure Wound Therapy, and Skin Grafting Joint Arthrodesis Metatarsophalangeal Joint Arthrodiastasis and Biologic Resurfacing with External Fixation: A Case Report Metatarsophalangeal Joint Arthrodesis Arthrodesis for Charcot Arthropathy Arthrodesis

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