Tibiotalocalcaneal Fusion With a Plate

54 Tibiotalocalcaneal Fusion with a Plate

Clifford L. Jeng


Arthrodesis of the tibiotalar and subtalar joints is a procedure to alleviate arthritis pain, correct deformity, or provide stability. The procedure is done through a transfibular approach, which provides excellent visualization of the two joints for preparation. Excellent correction of even severe deformities can be accomplished with this approach. Multiple dedicated tibiotalocalcaneal fusion plate systems are available, but alternative fixation can be achieved with a pediatric blade plate or proximal humeral locking plate inserted “upside-down” as well.

Keywords: tibiotalocalcaneal, ankle, subtalar, arthritis, arthrodesis

54.1 Indications

• Ankle and hindfoot arthritis.

• Ankle deformity.

• Avascular necrosis of the talus.

• Charcot arthropathy.

• Failed total ankle replacement.

• Failed arthrodesis.

• Flaccid paralysis.

• Trauma.

• Rheumatoid arthritis.

• Reconstruction after tumor resection.

• Osteomyelitis.

54.1.1 Clinical Evaluation

• Standing alignment of both the operative leg and normal contralateral leg to determine desired limb alignment and any limb length inequality.

• Evaluation of the ankle joint, subtalar joint, and transverse tarsal joints to determine arthritic involvement and which joints need to be included in the fusion procedure.

• Vascular evaluation to determine circulation with noninvasive arterial ultrasound studies if there are no palpable pedal pulses.

54.1.2 Radiographic Evaluation

• Weight-bearing plain radiographs of the foot and ankle, including a heel alignment view.

• Computed tomography (CT) scan and magnetic resonance imaging (MRI) as needed to assess alignment, quality of bone, and presence of avascular necrosis.

• White cell–labeled nuclear scintigraphy to assess for potential infection if there is a clinical concern.

54.1.3 Contraindications

• Active infection.

• Poor soft-tissue envelope.

• Inadequate bone stock to hold fixation.

• Medical comorbidities.

• Inability to remain non-weight-bearing or to comply with postoperative protocols.

• Metal allergy.

• Relative contraindications include peripheral vascular disease, uncontrolled diabetes, and smoking.

54.1.4 Nonoperative Options

• Brace immobilization.

• Activity modification.

• Rocker bottom sole and cushioned heel to shoe; orthotic inserts.

• Medications: cortisone injection; hyaluronic acid injections; anti-inflammatory medications.

54.2 Goals of Surgical Procedure

• The goal of a tibiotalocalcaneal arthrodesis is a stable, plantigrade, painless limb.

54.3 Advantages of Surgical Procedure

• The biggest advantage of plate fixation is that there are more points of fixation available in the calcaneus compared to an intramedullary rod.

• There is also less risk of injury to the plantar nerves because no incision or reaming is required on the plantar aspect of the heel.

Disadvantages: The main downside to lateral plate fixation is that the plate is not load-sharing, and if a nonunion occurs, the screws will eventually break. An additional disadvantage is that if a wound-healing problem occurs, the lateral plate is more likely to get infected and require removal.

54.4 Key Principles

• Appropriate debridement and preparation of the joint surfaces of the ankle and subtalar joints for fusion.

• Reestablish anatomic alignment of the ankle and subtalar joints in neutral (0 degrees) dorsiflexion and 5 to 10 degrees of valgus and 10 degrees of external rotation.

• Compression of the ankle and subtalar joints through a separate screw from the calcaneus into the distal tibia anteriorly.

• Rigid fixation of the ankle and hindfoot with the plate.

54.5 Preoperative Preparation and Patient Positioning

It is easiest to do this procedure in the lateral decubitus position as long as no additional medial-sided work needs to be done. Assessing alignment can be slightly more difficult in this lateral position, especially rotational alignment. Supine or “sloppy lateral” positions are also acceptable positions that make it easier to approach the medial ankle gutter through a separate arthrotomy or to include a talonavicular fusion to the procedure. Make sure that the patient is well padded with axillary roll if necessary and egg crate/sponge under the down side. A thigh tourniquet is helpful given this procedure can be fairly bloody. A popliteal block or other regional anesthesia prior to the induction of general anesthesia can be helpful for postoperative pain relief. The operative limb should be prepped and draped above the knee so that alignment of the fusion can be accurately assessed and proximal tibial bone graft can be harvested if necessary. TED hose and a sequential compression device on the down leg during surgery may be helpful in preventing deep venous thrombosis. Preoperative intravenous antibiotics must be given. A Foley catheter may be helpful to avoid excessive bladder distension during what can often be a lengthy anesthetic.15

54.5.1 Anatomic Issues to Consider

The sural and superficial peroneal nerves are vulnerable in this approach. The sural nerve is found distally over the calcaneal tuberosity and the superficial peroneal nerve proximally near where the fibula is transected. The fibula is difficult to remove due to the strong interosseous membrane and syndesmotic ligaments. Once the fibula is removed, it is important to find and cauterize the peroneal artery, which will be cut from incising the interosseous membrane. The peroneal tendons at the distal end of the incision can be either retained or excised. There are no long-term negative effects from excising the peroneal tendons. Two large bony prominences, the lateral process of the talus and the Chaput tubercle of the tibia, interfere with laying the plate flat against the bone. These must be removed in order to position the plate flush, which is important because if the plate is elevated off the bone, it can be difficult to obtain a good closure distally. The posterior facet of the subtalar joint is surprisingly vertical. The middle facet of the subtalar joint is visualized distal and medial to the posterior facet and should be prepared as well to maximize fusion surface area. The medial gutter of the ankle joint can be prepared either across the ankle using a lamina spreader and angled curettes or through a separate anteromedial arthrotomy. Throughout the procedure, be careful not to injure the neurovascular bundles lying anteriorly and posteromedially.6

54.6 Operative Technique

54.6.1 Surgical Approach

Make a 15-cm longitudinal incision centered over the middle of the fibula. It is helpful to use the planned internal fixation plate to measure how proximal the fibula will need to be transected. Dissect through the subcutaneous tissue in order to identify the superficial peroneal and sural nerves. The superficial peroneal nerve will be in the proximal aspect of incision running from posterior to anterior. The sural nerve will be distal in the incision over the calcaneal tuberosity. The sural nerve always runs together with a large vein from posterior to anterior. Protect these nerves and then incise directly down to bone on the fibula, talus, and lateral aspect of the calcaneus. Expose subperiosteally the fibula and lateral malleolus. Identify the syndesmosis anteriorly with a scalpel blade and then use a Cobb elevator or osteotome to release the syndesmosis and interosseous membrane between the tibia and fibula. Use Hohmann retractors anterior and posterior to the fibula as far proximally as your incision will allow and make a fibular osteotomy using a sagittal saw. The osteotomy should be either transverse or beveled slightly distally to avoid a sharp point underneath the skin. Continue to release what is left of the interosseous membrane and syndesmosis until the fibula is free and remove it to the back table to be harvested for bone graft. Find the peroneal artery which is routinely cut in this approach and cauterize it (Figs. 54.1, 54.2).

54.6.2 Joint Exposure

Identify the ankle and subtalar joints. The peroneal tendons cover the posterior facet of the subtalar joint and may be either retracted during joint preparation or excised. There are no long-term negative effects of excising the peroneal tendons. Approach the subtalar joint first, using scalpel and rongeur to remove the contents of the sinus tarsi including the interosseous ligament which will interfere with distracting the joint open. An elevator can then be inserted into the subtalar joint and twisted to pry apart the capsular ligaments. Once this is complete, insert a toothed lamina spreader into the sinus tarsi and distract open the posterior facet of the subtalar joint. Further debridement medially is necessary to see the middle facet of the joint (Fig. 54.4). Now remove the lamina spreader and insert it in between the tibia and talus to expose the ankle joint. If it is too tight, a Cobb elevator can be passed anterior and posterior to the ankle joint to gently pry off the capsule, and a scalpel can then be used to release subperiosteally around the joint. Be careful not to overstrip the periosteum, which may damage the blood supply to the tibia and talus and impair healing. An elevator can then be inserted between the tibia and talus and twisted to pry open the remaining capsular ligaments. Now a toothed lamina spreader is inserted between the tibia and talus to fully expose the joint for preparation (Fig. 54.3).

Jul 19, 2019 | Posted by in SPORT MEDICINE | Comments Off on Tibiotalocalcaneal Fusion With a Plate

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