Christopher P. Chiodo and Catherine E. Johnson
DEFINITION
Tibiotalocalcaneal arthritis is formally defined as the loss of cartilage from both the tibiotalar (ankle) and the talocalcaneal (subtalar) joints.
Tibiotalocalcaneal arthritis can cause significant disability in terms of pain and limitation of function. Nonoperative treatment options are limited, as in most instances they only partially relieve pain and usually cannot correct deformity.
The goal of tibiotalocalcaneal arthrodesis is to produce a stable, plantigrade, pain-free foot and ankle.
Achieving stable fixation can be challenging in osteopenic bone. Blade plate fixation of the tibiotalocalcaneal joint has been shown in biomechanical studies to have higher initial and final stiffness.
ANATOMY
The ankle joint comprises the talus as it articulates with the tibial plafond. The body of the talus is saddle-shaped dorsally and fits congruently within the mortise created by the distal tibia and fibula. In addition, the talus and the tibial plafond are narrower posteriorly to accommodate rotation with ankle dorsiflexion and plantarflexion.
The subtalar joint comprises the talus and the calcaneus as they articulate through anterior, middle, and posterior facets.
The talus is divided into head, body, and neck. Roughly 70% of the bone is covered with cartilage, and there are no muscular or tendinous attachments. The main blood supply of the talar body enters retrograde through the neck of the talus, which makes the body prone to avascular necrosis in the case of displaced talar neck fractures.
The lateral aspect of the foot is innervated by the superficial peroneal and sural nerves. The superficial peroneal nerve typically exits the crural fascia 10 to 12 cm proximal to the tip of the lateral malleolus. The nerve then courses anteriorly to give sensation to the dorsal aspect of the foot.
The sural nerve has contributions from branches of both the tibial and common peroneal nerves. It courses lateral to the Achilles tendon and is found about 1 cm distal to the tip of the fibula at the level of the ankle.
PATHOGENESIS
Arthritis of the tibiotalar and subtalar joints has multiple causes, including primary osteoarthritis, trauma, neuroarthropathy, infection, avascular necrosis, inflammatory arthritis, and failed surgery.
Patients typically complain of diffuse ankle pain and cannot differentiate tibiotalar from subtalar symptoms. Although it is preferable to fuse only one joint to retain an adjacent motion segment, such isolated fusion in the setting of residual arthrosis can result in persistent pain.
In posttraumatic cases, failure to restore articular congruency can result in increased contact stresses, with resultant cartilage wear and the development of arthritis.
NATURAL HISTORY
Hindfoot arthritis is usually a progressive disorder, although the rate of progression can vary. However, arthritis due to malalignment, trauma, and avascular necrosis of the talus can progress relatively rapidly.
Nonoperative treatment of hindfoot arthritis in an ankle–foot orthosis (AFO) likely does not prevent or slow progression of the disease, but merely decreases symptoms.3
Failed surgery can be quite debilitating and frequently needs expedited treatment.
PATIENT HISTORY AND PHYSICAL FINDINGS
Physical examination should include:
Gait. The surgeon should watch the patient walking both toward and away from him or her and should clinically determine whether gait is normal or antalgic on both sides. The examiner should look for any assistive devices. Patients with painful arthritis will have an antalgic gait on that side. The patient may require the use of a cane or a walker.
Hindfoot alignment. The hindfoot is examined from behind. The surgeon should determine whether the hindfoot is in varus or valgus. Patients can have both varus and valgus malalignment.
Tibiotalar range of motion. Active and passive sagittal plane motion is assessed. Normal ankle motion is about 50 degrees of plantarflexion and 10 to 20 degrees of dorsiflexion. Tibiotalar motion is usually significantly decreased compared to the unaffected side.
Subtalar range of motion. Active and passive coronal plane motion is assessed. Normal subtalar motion is about 10 to 20 degrees of inversion and 5 to 10 degrees of eversion. Subtalar motion is usually significantly decreased compared to the unaffected side.
Past medical history may be significant for antecedent ankle or hindfoot trauma, talar osteonecrosis, diabetes, neuroarthropathy, osteochondral defect, or recurrent ankle instability.
Past surgical history may include previous ankle or hindfoot surgery, including open reduction and internal fixation, total ankle arthroplasty, and previous arthrodesis.
Patients usually complain of pain and instability with weight bearing. Selective anesthetic injections into the ankle or subtalar joints can help to determine which joints are symptomatic.
Upon examination, hindfoot swelling and tenderness are usually evident. Most patients have decreased passive range of motion in both joints. Malalignment is also often present.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Weight-bearing plain radiographs including AP, lateral, and mortise views of the ankle and AP, lateral, and oblique views of the foot are standard.
FIG 1 • Preoperative AP (A) and lateral (B) radiographs of the ankle.
A weight-bearing lateral should be performed to assess talo–calcaneal and talo–first metatarsal angles (FIG 1).
CT is often helpful preoperatively to assess bony anatomy, alignment, and articular integrity in greater detail.
DIFFERENTIAL DIAGNOSIS
Talar avascular necrosis
Talar osteochondral injury
Isolated ankle arthritis
Isolated subtalar arthritis
Ankle instability
Foreign body
NONOPERATIVE MANAGEMENT
Nonoperative treatment is aimed primarily at alleviating symptoms rather than correcting deformity. The patient is placed in a robust brace such as an ankle–foot arthrosis (AFO) or Arizona brace in an attempt to provide support and limit motion.
Bracing may not always be possible depending on the severity of the deformity. In addition, bracing typically does not prevent progression of disease.
SURGICAL MANAGEMENT
Surgical management is generally indicated when nonoperative modalities have failed to provide adequate relief or are impractical (eg, a non-braceable deformity).
Tibiotalocalcaneal fusion is indicated in patients with arthritis in both the tibiotalar and subtalar joints. The goal of surgical intervention is to obtain a stable, plantigrade, and pain-free foot and ankle.
Blade plate fixation can be used primarily or in instances when the surgeon feels that intramedullary rod fixation is contraindicated. The latter may include poor bone stock or advanced osteopenia, a distal tibia deformity greater than 10 degrees, or significant loss of calcaneal height.10
The main two contraindications to this procedure are (1) the presence of active infection and (2) destruction of calcaneal bone stock to the extent that purchase with the blade is compromised. In these instances, the use of a small wire ring fixator should be considered.
Preoperative Planning
A full patient assessment is made before the operation. Smokers should be counseled with regard to smoking cessation because in this population, a 14-fold increase in the nonunion rate has been documented.4
If active infection is suspected, an appropriate workup should be performed. This may include laboratory studies, MRI with contrast, and nuclear imaging. If there is still uncertainty despite these tests, a bone biopsy or joint aspirate may be necessary.
Disease-modifying antirheumatic drugs (DMARDs) should be held preoperatively, typically for 2 weeks or a period determined in conjunction with a rheumatologist.
Patients with significant comorbidities such as diabetes, cardiovascular disease, and nephropathy should be medically optimized by their primary care doctor before surgical intervention.
Positioning
The patient is placed supine on the operating table with a bump under the ipsilateral buttock to maintain the foot in neutral or slightly rotated medially.
The extremity is prepared and draped, including the iliac crest if structural autograft is desired. An alternative bone graft harvest site is the proximal tibia. A thigh tourniquet is used (FIG 2).
Approach
Traditionally, an extensile lateral approach to the ankle and subtalar joints is used, although a posterior approach has also been described.8
A 15to 20-cm curvilinear incision is made through the skin centered over the fibula shaft proximally, then curving toward the base of the fourth metatarsal distally.
FIG 2 • Preoperative positioning of the patient.
With deep dissection, care is taken to avoid injury to the superficial peroneal nerve, which exits the fascia about 12 cm proximal to the fibular tip. Distally, the surgeon must take care to avoid injury to the sural nerve along its course lateral to the fifth metatarsal (FIG 3).
Distally, the extensor digitorum brevis is elevated to expose the subtalar joint.
In some instances, a medial (longitudinal) incision may be necessary. These include (1) to remove medial bony prominences and debris and (2) to assist in resection of medial bone when advanced varus deformity precludes reduction of the foot to neutral.
FIG 3 • The ankle and subtalar joints are approached through an extensile curvilinear incision.
TECHNIQUES
OSTEOTOMY OF THE FIBULA AND PREPARATION OF THE TIBIOTALAR JOINT
Make an osteotomy of the fibula about 6 to 10 cm proximal to the tip of the lateral malleolus (TECH FIG 1). Resect the distal section of the fibula. If desired, this can be morselized for bone graft. Retract the peroneal tendons posteriorly and protect them.
Enter the ankle joint sharply and fully expose it by releasing the lateral ligaments and anterior and posterior capsule.
Distract the joint using a lamina spreader.
Remove any remaining cartilage with a curette.
After removing the cartilage, prepare the joint surface with flexible chisels or a small, low-speed burr. If using a burr, use copious irrigation to avoid thermal necrosis. Burr holes should be just through the subchondral bone and separated by about 3 mm on all sides to avoid weakening or fracture of the cortex.
TECH FIG 1 • An osteotomy of the fibula is performed about 6 to 10 cm proximal to the tip of the bone.
PREPARATION OF THE SUBTALAR JOINT
Enter the subtalar joint sharply with release of the lateral ligaments, capsule, and the talocalcaneal intraosseous ligament.
Maintain distraction of the joint using a lamina spreader.
Curette the remaining cartilage off the joint surface and prepare the subchondral bone with flexible chisels or a burr as described above.
If there is significant bone loss or fragmentation of the talus, the tibia may have to be fused directly to the talus. In this case, the calcaneal articular processes will need to be removed with an osteotome to create a flat surface that will lie flush with the tibial plafond.
Bone graft can be packed into the subtalar and ankle joints. If there is a large bony deficit with substantial loss of limb length, structural graft in the form of iliac crest autograft or femoral head allograft can be used to restore height.
INSERTION OF THE BLADE PLATE
After preparing the joint surfaces, insert a 90 or 95-degree fixed-angle blade plate for fixation. The use of both an adolescent blade plate and a humeral blade plate has been described. The length of the blade is typically 40 mm. The side plate can range from five to eight holes based on the size of the patient and the surgeon's preference.
Ensure that the hindfoot is positioned in neutral to 5 degrees of valgus and the ankle is in neutral dorsiflexion and plantarflexion. External rotation should approximate that of the contralateral extremity, usually 5 to 10 degrees.
TECH FIG 2 • A. A 2.0-mm guidewire is inserted through the drill guide into the calcaneus. B. The blade plate is inserted over the guidewire using the insertion handle.
The ankle and subtalar joints must be held rigidly during insertion of the blade plate. Provisional fixation can be obtained with guidewires or a Schanz pin.
Use a 2.0-mm guidewire to facilitate insertion of the blade plate. The guidewire should be inserted such that 5 to 10 mm of calcaneal bone will remain plantar to the blade. Place the guidewire through the middle hole of the blade plate drill guide (TECH FIG 2A). The lateral calcaneal cortex may then be further prepared for blade insertion by predrilling with a 4.5-mm drill bit (through appropriate holes in the drill guide).
Remove the drill guide and insert the blade plate over the guidewire using the inserter–extractor handle (TECH FIG 2B). Impact the blade until it is flush with the lateral cortex of the tibia. Rotational control is best achieved by using a slotted hammer.
Contour the plate to the lateral aspect of the tibia and fill the screw holes sequentially. Use 4.5-mm cortical screws proximally and 6.5 mm cancellous screws distally.
A single 6.5-mm or 7.3-mm cortical screw can be used to augment the blade plate fixation. Place the screw under fluoroscopic guidance from the calcaneal tuberosity into the anterior tibial cortex at roughly a 60-degree angle.
Closure
Given the large amount of bleeding cancellous bone exposed during the procedure, a meticulous layered closure should be performed. Further steps that will aid in the prevention of a postoperative hematoma include releasing the tourniquet and assessing hemostasis before closure, the use of drains, and the use of a compression dressing.
POSTOPERATIVE CARE
Postoperatively, patients are placed in a splint and admitted for 24 hours of intravenous antibiotics.
After 10 to 14 days, patients return to the office for evaluation of the wound and suture removal. At this visit patients are placed in a non–weight-bearing short-leg cast.
Patients remain non–weight-bearing in a short-leg cast for 6 to 12 weeks, based on radiographic healing.
Thereafter, patients are transitioned to a short-leg walking cast or boot and progressive weight bearing is begun.
The fusion is protected until sufficient clinical and radiographic healing is obtained (FIG 6). A CT scan may be needed to assess the adequacy of the fusion.
OUTCOMES
A successful outcome is usually the norm for tibiotalocalcaneal fusion.
Most studies report combined results of different approaches to fusion. In studies examining the use of blade plate fixation exclusively, the reported fusion rates have ranged from 90% to 100%.2,8,10
FIG 6 • Postoperative radiographs showing healing. In this case, the talus was “replaced” with a carefully contoured femoral head allograft.
COMPLICATIONS
Overall complication rates for tibiotalocalcaneal fusion have been as high as 50% in some series.3,5 The most common complications include nonunion, malunion, infection, and neuroma.
In patients undergoing tibiotalocalcaneal fusion (regardless of fixation technique) the nonunion rate ranges from 0% to 40%. This is most common when there is avascular necrosis of the talus. In this patient population, the nonunion rate has been as high as 89%.5 Nonunion rates are also significantly higher in smokers and patients with neuroarthropathy (33% to 75%).4,5
Superficial and deep wound infection can be minimized through the use of appropriate perioperative antibiotics, meticulous soft tissue handling, a layered wound closure, avoidance of hematoma formation, and postoperative elevation.
Peripheral neuroma of either the sural or superficial peroneal nerves can be minimized by careful incision placement and gentle retraction and soft tissue handling. In patients with neuroarthropathy, there is usually decreased if not absent distal sensation. In these patients, peripheral nerve injury is usually clinically insignificant.
REFERENCES
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2. Chiodo CP, Acevedo JI, Sammarco VJ, et al. Intramedullary rod fixation compared with blade-plate-and-screw fixation for tibiocalcaneal arthrodesis: a biomechanical investigation. J Bone Joint Surg Am 2003;85A:2425–2428.
3. Chou LB, Mann RA, Yaszay B, et al. Tibiocalcaneal arthrodesis. Foot Ankle Int 2000;21:804–808.
4. Cobb TK, Gabrielsen TA, Campbell II DC, et al. Cigarette smoking and nonunion after ankle arthrodesis. Foot Ankle Int 1994;15: 64–67.
5. Cooper PS. Complications of ankle and tibiotalocalcaneal arthrodesis. Clin Orthop Relat Res 2001;391:33–44.
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9. Morrey BF, Wiedeman GP. Complications and long-term results of ankle arthrodesis following trauma. J Bone Joint Surg Am 1980;62A: 777–784.
10. Myerson MS, Alvarez RG, Lam PWC. Tibiocalcaneal arthrodesis for the management of severe ankle and hindfoot deformities. Foot Ankle Int 2000;21:643–644.
11. Papa JA, Myerson MS. Pantalar and tibiotalar calcaneal arthrodesis for post-traumatic osteoarthritis of the ankle and hindfoot. J Bone Joint Surg Am 1992;74A:1042–1049.
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