You are in: eMedicine Specialties > Orthopedic Surgery > FOOT AND ANKLE Triple ArthrodesisArticle Last Updated: Feb 28, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Stephen M Schroeder, DPM, Chairman of Podiatric Foot and Ankle Surgery, Medical Staff, Department of Surgery, The Vancouver Clinic Coauthor(s): Enzo Sella, MD, Chief, Orthopedic Foot and Ankle Surgery, Yale-New Haven Hospital; Associate Clinical Professor, Department of Orthopedics and Rehabilitation, Yale University School of Medicine; Peter Blume, DPM, Director of Diabetic Foot Surgery, Department of Orthopedics, Yale New Haven Hospital; Clinical Assistant Professor, Department of Podiatric Surgery, Yale University School of Medicine; Raymond O'Hara, DPM, Chief Resident, Department of Orthopedic Surgery, Yale-New Haven Hospital Editors: Heidi M Stephens, MD, Associate Professor, Department of Surgery, Division of Orthopedic Surgery, Director of Diabetic Foot Clinic, Assistant Dean for Clinical Outreach, University of South Florida College of Medicine; Courtesy Joint Associate Professor, Department of Environmental and Occupational Health, University of South Florida College of Public Health; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Shepard R Hurwitz, MD, Executive Director Designate, American Board of Orthopaedic Surgery; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Jason H Calhoun, MD, FAAOS, Chairman, J Vernon Luck Distinguished Professor, Department of Orthopedic Surgery, University of Missouri Author and Editor Disclosure Synonyms and related keywords: joint fusion, talocalcaneal joint, talonavicular joint, calcaneocuboid joint, TC joint, TN joint, CC joint, foot arthrodesis, foot joints, degenerative joint disease, DJD, degenerative arthritis, arthritis, foot arthritis, varus deformity of the foot, valgus deformity of the foot INTRODUCTIONSection 2 of 12
  A triple arthrodesis consists of the surgical fusion of the talocalcaneal (TC), talonavicular (TN), and calcaneocuboid (CC) joints in the foot. The primary goals of a triple arthrodesis are to relieve pain from arthritic, deformed, or unstable joints. Other important goals are the correction of deformity and creation of a stable, balanced plantigrade foot. History of the ProcedureEdwin W. Ryerson first described triple arthrodesis in 1923 as a fusion of the TC, TN, and CC joints.1 The goal was to create a well-aligned, plantigrade, and stable foot that would allow patients with paralytic or deforming conditions to function better. The most common indications were to correct lower extremity deformities in children resulting from poliomyelitis, cerebral palsy, Charcot-Marie-Tooth disease, clubfoot, or tuberculosis. The original procedures were performed by removing large blocks of subchondral bone and correcting the angular deformities by inserting or removing wedges. The corrections were maintained by casting that often required later manipulation for loss of position. Kirschner wires (K-wires), Steinmann pins, and staples were used over time to hold the corrections in place. Internal fixation with Association for the Study of Internal Fixation (AO/ASIF) technique and various compression screws has become standard. ClinicalPresentations in the office or clinic can vary, depending on the underlying pathology. A common feature of patients is the development of degenerative joint disease (DJD). Conditions that produce an improperly functioning, unstable foot that leads to DJD are the main indications for surgical treatment. Subtalar joint (STJ) arthritis usually manifests as pain located anterior to the distal tip of the fibula in the region of the sinus tarsi. The pain is exacerbated with forced inversion and eversion of the heel. In advanced cases, crepitation is noted with forced range of motion (ROM). Similar findings can be seen in the CC and TN joints. Pain is usually elicited with periarticular palpation. Depending on the underlying pathology, the patient may present with a varus or valgus deformity or neither. Posttraumatic arthritis often presents with a rectus foot and complaints consistent with DJD of the STJ. It commonly occurs after calcaneal fractures with posterior facet involvement. Depending on the severity of the fracture, the heel can be shortened, can be widened, and can have an uneven lateral wall with bony prominences (see Images 1-4). These findings are typically seen in lateral wall blowout fractures that do not undergo open reduction with internal fixation (ORIF). Similar fractures with inadequate ORIF or varus or valgus deformity can also be seen in these cases. Valgus deformities are commonly seen in collapsing pes planovalgus, late-stage tibialis posterior tendon dysfunction, tarsal coalition, and some neuromuscular conditions. They are easy to identify, especially in the latter stages of the deformity, and present with a heel in valgus, an abducted forefoot, and a medial arch that is typically collapsed (see Images 5-9). Varus foot deformities are seen in cavus foot types, cavovarus foot types, talipes equinovarus, and some neuromuscular conditions. The most common neuromuscular condition presenting with a varus deformity is Charcot-Marie-Tooth disease (see Images 10-14). This deformity is also fairly easy to identify. The patient will have a heel that is in a varus position, an adducted forefoot, a higher than normal arch, and ankles that are storklike. INDICATIONSSection 3 of 12
Triple arthrodesis should be considered as a salvage procedure and only used after other treatment modalities have been exhausted. In conditions in which a lesser fusion or soft-tissue procedure will suffice, triple arthrodeses should not be used because of the potential long-term complications associated with it. The primary indications for the procedure are as follows2:
RELEVANT ANATOMYSection 4 of 12
The bony anatomy consists of the talus, calcaneus, cuboid, and navicular. The talus and calcaneus make up the STJ. Its articular portion is composed of the more important posterior facets of the talus and calcaneus and the smaller anterior and middle facets. The anterior talofibular, posterior talofibular, calcaneofibular, deltoid, and interosseous TC ligaments stabilize it. Subtalar motion is triplanar and is described appropriately as pronation (dorsiflexion, eversion, and external rotation) and supination (plantarflexion, inversion, and internal rotation). Clinically, however, most motion takes place in the frontal plane and is seen as heel eversion and inversion. Although normal ROM values are difficult to measure, a practical rule of thumb is 30° of total motion with approximately 10° of inversion and 20° of eversion. The sinus tarsus is a tunnellike structure extending from distal lateral to posterior medial in the rearfoot. It is formed dorsally by the concavity in the neck of the talus and plantarly by the sulcus between the posterior facet and sustentaculum tali of the calcaneus. This structure is widest laterally and contains the bifurcate, cervical, and interosseous ligaments. It is filled by a fatty plug known as the Hoke tonsil and serves as the origin of the extensor digitorum brevis (EDB) muscle. The head of the talus and the navicular constitute the TN joint. This is a condylar joint. The head of the talus is convex, and the corresponding surface of the navicular is concave. This is an important spatial relationship to understand because the navicular forms a lip around a portion of the talar head, making it difficult to fully access the joint and remove adequate amounts of cartilage. Normally, during stance phase, the calcaneus everts, and the talus plantarflexes and internally rotates. This action produces a relative dorsiflexion, eversion, and abduction of the navicular, which subsequently translates that motion to the forefoot. In excessive or pathologic cases, this presents as medial arch collapse with forefoot abduction. The opposite takes place with weight-bearing STJ supination. The anterior articular portion of the calcaneus and cuboid make up the CC joint. This is often the first joint resected during a triple arthrodesis and is the most easily accessible of the 3 joints. Directly superior to the joint is the EDB muscle belly and lateral to it are the peroneal tendons. The sural nerve courses along the lateral side of the foot, and the superficial peroneal nerve takes a more dorsal lateral position. It should be noted that there is significant anatomic variation of the sural nerve and care must be exercised when making the incision. The lateral incision is placed between these 2 nerves. The saphenous nerve and vein enter the foot on the dorsal medial aspect. A medial incision is also made and is usually located in line and just plantar to these structures. CONTRAINDICATIONSSection 5 of 12
Contraindications to triple arthrodesis include conditions that can be adequately corrected and maintained via external bracing, soft-tissue procedures and tendon balancing, or lesser fusions. Chronic smoking is a relative contraindication due to the associated high incidence of nonunion. WORKUPSection 6 of 12
Lab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
TREATMENTSection 7 of 12
Medical therapyAs with most cases, nonsurgical measures should be exhausted before considering surgical intervention. This is especially true when planning a salvage procedure like a triple arthrodesis. Conservative treatment consists of physical therapy, strapping and tapping, nonsteroidal anti-inflammatory drugs (NSAIDs), steroid injections, and bracing. Surgical therapyMost triple arthrodesis procedures are performed by removing all of the cartilage from the three joints and fusing them with bone-to-bone contact. Positional corrections can usually be achieved by rotating the foot along the natural contours of the joint surfaces prior to fusion. In cases of severe deformity, however, wedges of bone may need to be removed from or added to the joints to achieve the desired correction.4, 5, 6, 2, 3, 7, 8, 9, 10, 11 Preoperative detailsThe patient is placed supine on the operating table and either general or spinal anesthesia is administered. A proximal thigh tourniquet is applied, and a sandbag is placed under the ipsilateral hip. This positioning internally rotates the foot and allows easier access to the lateral incision and the ipsilateral iliac crest should autogenous bone graft be needed. Intraoperative detailsA lateral incision is made from just inferior to the distal tip of the lateral malleolus to the base of the fourth metatarsal (see Images 23-24). The STJ, CC joint, and the lateral portion of the TN joint are thereby exposed. Care is taken to avoid branches of the sural and superficial peroneal nerves running just inferior and superior to the incision. This approach follows a plane between both nerves, but small branches may enter the area and should be avoided if possible. The deep fascia is visualized through the entire course of the incision, and the EDB muscle belly is identified. An L-shaped incision is made through the deep fascia traveling along the course of the EDB insertion and then distally across the CC joint (see Image 25). This releases the insertion of the EDB, allows access to the CC joint, and gives exposure to the sinus tarsi and the Hoke tonsil. The EDB muscle belly is flapped distally, starting at its proximal lateral margin, giving excellent exposure to the CC joint and allowing eventual exposure to the lateral TN joint. The Hoke tonsil is next evacuated by carefully following the contours of the calcaneus with a No. 15 blade beginning at the anterior process (see Image 26). Care should be taken to identify and protect the peroneal tendons. All of the contents of the sinus tarsi should be removed, including the interosseous ligament, to gain exposure to the anterior portion of the STJ. A laminar spreader is placed into the sinus tarsi and used to open the STJ, vertically separating the talus from the calcaneus. Transection of the calcaneofibular (CF) ligament may become necessary in cases in which the joint remains tight and adequate exposure is not achieved. Articular cartilage is removed from the anterior, middle, and posterior facets by scraping with a curette or stripping with an osteotome. The remaining subchondral bone is then fenestrated using a 0.062 K-wire, small drill bit, or power bur. This allows vascular ingrowth through the subchondral plate and excellent bone preparation for fusion. Another method for penetrating the subchondral bone is to use a small osteotome or gouge to shingle the surface. Attention is next directed to the CC joint where the cartilage is denuded, leaving only subchondral bone. The surfaces are fenestrated in the fashion described above. Care should be taken to leave as much bone as possible at this joint, especially in valgus deformities, because lateral column length is important for correction. The lateral border of the TN joint can be reached after the CC joint is prepared by dissecting directly medially. A capsulotomy is performed and the laminar spreader is once again used to separate the articular surfaces. Any cartilage that can be removed through this incision should be before starting the medial approach. A medial incision is made beginning just anterior to the distal tip of the medial malleolus extending dorsomedially toward the naviculocuneiform joint (see Images 27-28). It lies between the anterior and posterior tibial tendons. The saphenous vein and nerve are typically located slightly dorsal to the incision and should be carefully retracted away during the dissection. A capsulotomy of the TN joint is performed in line with the skin incision, and periosteal flaps are created to expose the articular surface. A laminar spreader is inserted for exposure, and the cartilage is removed. The articular surface of the navicular is usually deeply concave making cartilage excision difficult. Care must be taken, however, to ensure the surface is properly denuded. Osteophytes and a large medial tubercle, if present on the navicular, can be removed. The foot is next manipulated into the corrected position and bone on bone contact at each joint is confirmed. Larger deformities may require wedges to be removed for optimal correction. Small gaps in joints can be filled with bone graft to help ensure solid union. Once satisfied that the foot will reduce properly, it is temporarily fixated. The STJ should be placed in about 4° of valgus relative to the ground. It is extremely important that the STJ not be left in varus, as this will most certainly lead to postoperative complications. Once again the most important thought to keep in mind during this procedure is "thou shall not varus!" The forefoot is then aligned plantigrade to the floor. Fixation techniques vary and often depend on surgeon preference. The STJ should be fixated with a cannulated 6.5 or larger screw and can be placed from the posterior plantar portion of the calcaneus into the body of the talus or from the neck of the talus into the body of the calcaneus (see Images 29-31). Care should be taken not to disrupt nutrient arteries entering the neck of the talus if the latter approach is used. The TN and CC joints can be fixed with either staples or screws. If staples are used, at least 2 are placed in each joint directed at 90° angles to each other. The technique preferred by the authors is to use two 4.5 cannulated screws placed parallel to each other in the TN and CC joints and to use a single 7.3 cannulated screw in the STJ (see Image 31). This technique works very well and spares time because the guide pins are used as temporary fixation. Once in place, the corrected position is verified using fluoroscopy, and the screws are easily placed over the guide pins. Screw placement is verified using fluoroscopy, and residual gaps in joints, including the sinus tarsi, are filled with bone graft. The surgical sites are closed in layers with care taken to repair the CF ligament and insertion of the EDB. A lateral drain should be used to help prevent hematoma formation, especially when large portions of bone are resected. If a preoperative block was not performed, an ankle block with 0.5% plain Marcaine is performed to help decrease postoperative pain. Finally, a Jones-style compression dressing is applied with a posterior splint prior to deflation of the tourniquet. Postoperative detailsPatients are usually kept overnight in the hospital for observation, pain control, and IV antibiotics. After discharge, patients are instructed to spend at least the first three days with their foot elevated above their heart in order to control edema and pain. Sutures are removed after two weeks and the patient is placed into a non–weight-bearing (NWB) removable boot. If excellent fixation was achieved during the procedure, ROM exercises may begin. If in doubt, a NWB short leg cast is applied. The authors have also used external electric stimulation from the first day postoperatively with good success. Follow-upThe patient remains NWB for 6-8 weeks and is then reevaluated. At that time, the patient is allowed to bear weight in a removable walker boot if no complications have arisen and trabeculation is noted on radiographs. A second set of films is obtained at approximately 12 weeks and evaluated for consolidation. If stable fusion is observed, the patient is taken out of the cast boot and allowed to progress to normal shoes. The patient should undergo physical therapy for continued ROM and strength training. Delayed union, especially at the TN joint, is not uncommon and may require further immobilization and NWB. For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center and Arthritis Center. Also, see eMedicine's patient education article Rheumatoid Arthritis. COMPLICATIONSSection 8 of 12
Because of the complex nature of the procedure and the various disease states being treated, complications after triple arthrodesis are relatively common. Those most frequently encountered are as follows: Nonunion As with any type of arthrodesis procedure, nonunion is a potential complication. In the case of the triple arthrodesis, the TN joint is the most common site, with most literature reporting a rate of 5-10%. This is probably related to poor preparation of the joint surfaces, which are difficult to expose, especially if only a single lateral incision is used. Adding a second medial incision provides much better access to the joint and allows for a more aggressive capsule release as well as easier distraction and better exposure for complete cartilage removal. A cadaveric study by Bono showed that only 38% of the cartilage from the TN joint was successfully removed using a lateral incision alone.7 Degenerative joint disease A properly functioning foot goes through a multitude of movements with each phase of the gait cycle. A high degree of these movements takes place at the ST, TN, and CC joints. Most foot pronation and supination occurs around these joints. Once these joints are fused, a large amount of stress is transferred to the joints immediately proximal and distal. Midfoot DJD can develop with time. An important intraoperative consideration is foot position. Excessive varus or valgus alignment of the rearfoot or forefoot can accelerate the onset of DJD. Wound healing problems Many of these patients are elderly or debilitated from an underlying disease process that requires chronic steroid therapy. These issues can lead to delayed wound healing most commonly seen as a mild dehiscence at the edges of the incision. Excessive postoperative edema can also delay healing. A rare situation that can cause large amounts of skin slough is placing the lateral tissues on stretch after reducing a large valgus deformity. An important point that must also be appreciated is the relatively small amount of subcutaneous and fatty tissue in the foot. Dissection should be meticulous with delicate handling of tissues, and healthy skin flaps need to be maintained. Nerve injury The placement of both the lateral and medial incisions are close to underlying nerves. The lateral incision lies between the sural and the superficial peroneal nerves. Small branches from each may be transected during the procedure. The intermediate dorsal cutaneous nerve, which is an extension of the superficial peroneal, is located very close to the distal portion of this incision. Variations of these nerves do exist and can cross the path of the standard lateral incision so careful dissection is warranted. The medial incision is located in proximity to the saphenous nerve as well as the medial dorsal cutaneous nerve at the distal margin of the wound. Entrapments within surgical scar tissue can take place in the postoperative period; however, painful neuromas rarely occur. When they do happen, standard conservative measures with appropriate medications, injections, and physical therapy should be used. If these measures fail, surgical neurolysis or proximal neurectomy with implantation into muscle is performed. Avascular necrosis This is a rare complication but has been reported.8 The predominant bone affected is the talus. The main reason for this is disruption of the blood supply while accessing the STJ, resecting a large portion of the talar head to increase correction of deformity, or excessive dissection of the talar neck while placing a screw from the talus down into the calcaneus. Lateral instability Lateral instability occurs for 2 main reasons. The first is malposition of the rearfoot in varus leading to excessive lateral stress on the ankle joint postoperatively. The other is inherent within the procedure. The CF ligament must often be transected for adequate exposure to the STJ. If the ligament does not heal properly, lateral ankle instability can result. Stiff foot Stiff foot is not so much a complication of the procedure as it is a result of the procedure. The motions of pronation and supination around the STJ allow the foot to adapt over uneven terrain. When the STJ is pronated, the entire foot becomes flexible. Conversely, when the STJ is supinated, the entire foot becomes rigid. These motions are normal and allow for shock absorption and conformation to surface terrain when pronated and propulsion when supinated. Once the three joints are fused, the foot becomes stiff and loses flexibility. This should be explained to the patient before surgery as something to expect postoperatively. Ankle motion is also affected. One report showed a 13% decrease in dorsiflexion and a 16% decrease in plantarflexion.9 OUTCOME AND PROGNOSISSection 9 of 12
Outcomes are typically good with high union rates of the subtalar and CC joints. The TN joint has the highest incidence of nonunion; however, this decreases with better understanding of the procedure and stable fixation. Degenerative changes at the unfused distal and proximal joints are still a long-term complication, but this is true with any fusion procedure. A study examining 400 triple arthrodesis procedures found less than perfect results in 24.5% of patients. Up to 10 months are required for the patient to become pain free. Return to high-impact activity is not a given. Lower-impact activities like walking, cycling, and swimming should be obtainable goals postoperatively. FUTURE AND CONTROVERSIESSection 10 of 12
The future and controversy for this procedure pertain to using external fixation devices. Proponents would argue it to be a stable fixation method that allows the patients to ambulate with partial to full weight bearing on the operative side. Others would argue that the risk of pin-tract infections is high and could be disastrous to the procedure's outcome. A study looked at 87 patients using a ring-style external fixation device. A 97% fusion at 6-8 weeks, with 36% developing superficial pin-site infections, was reported.11 MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
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