Tibiotalocalcaneal Arthrodesis with Intramedullary Fibular Strut Graft and Adjuvant Hardware Fixation.

Abstract

Background: In patients with irreparable damage to the articular surfaces of the hindfoot, hindfoot arthrodesis is frequently chosen to provide pain relief and improve activities of daily living. Common etiologies leading to hindfoot arthrodesis procedures include osteonecrosis, failed total ankle arthroplasty, and deformities resulting from Charcot arthropathy or rheumatoid arthritis. Traditionally, this operation utilizes an intramedullary nail to obtain fusion of the tibiotalocalcaneal joint. Although 80% to 90% of patients achieve postoperative union, the remaining 10% to 20% experience nonunion^1-3. Factors affecting the rate of nonunion include Charcot neuroarthropathy, use of nonsteroidal anti-inflammatory drugs or methotrexate, osteopenic bone, and smoking⁴. In the present video article, we describe a tibiotalocalcaneal arthrodesis performed with use of a fibular strut autograft for repeat arthrodesis following failure of primary tibiotalocalcaneal arthrodesis or as a salvage operation in end-stage pathologies of the hindfoot. Our surgical technique yields union rates of approximately 80% and provides surgeons with a viable surgical technique for patients with complex hindfoot pathologies or fusion failure.

Description: The patient is placed in the supine position, and a 10-cm curvilinear incision is made including the distal 6 to 8 cm of the fibula. The incision is centered directly lateral on the fibula proximally and transitions to the posterolateral aspect of the fibula distally. As the incision continues distally, it extends inferiorly and anteriorly over the sinus tarsi and toward the base of the 4th metatarsal, using an internervous plane between the superficial peroneal nerve anteriorly and the sural nerve posteriorly. Exposure of the periosteum is carried out through development of full-thickness skin flaps. The periosteum is stripped, and a sagittal saw is used to make a beveled cut on the fibula at a 45° angle, approximately 6 to 8 cm proximal to the ankle. The fibular strut is decorticated, drilled, and stripped of the cartilage on the distal end. Preparation of the tibiotalar and subtalar joints for arthrodesis are completed through the lateral incision. The foot is placed in 0° of dorsiflexion, 5° of external rotation in relation to the tibial crest, and 5° of hindfoot valgus while maintaining a plantigrade foot. This placement can be temporarily maintained with Kirschner wires if needed. Next, the plantar surface overlying the heel pad is incised, and a guidewire is passed through the center of the calcaneus and into the medullary cavity of the tibia. Correct alignment of the guidewire is then confirmed on fluoroscopy. The fibular strut autograft is prepared for insertion while the tibiotalocalcaneal canal is reamed to 1 to 2 mm larger than the graft. The graft is tapped into position, followed by placement of two 6.5-mm cancellous screws to immobilize the joint, taking care to avoid excess contact of the fibular graft with the screws.

Alternatives: Alternatives to this procedure include traditional arthrodesis techniques, nonoperative treatment (such as rehabilitation or bracing), or no intervention. Patients with failed primary hindfoot arthrodesis may undergo an additional traditional arthrodesis, but may face an increased risk of complications and failure^1,2.

Rationale: A recent study¹ has shown that the use of a fibular strut autograft for tibiotalocalcaneal arthrodesis produces union rates similar to those seen with the traditional intramedullary nailing technique^4,5. These results are important to note, as the presently described technique, which is used as a salvage procedure, produces outcomes that are equivalent to those observed for primary tibiotalocalcaneal arthrodesis with nailing, which is used for the treatment of severe trauma, extensive bone loss, or severe hindfoot pathologies. We recommend using this technique particularly in cases of failed primary tibiotalocalcaneal arthrodesis or in patients with end-stage hindfoot pathologies. The fibular strut autograft is a viable salvage option to decrease daily pain and provide quality improvement in patient activities of daily living.

Expected outcomes: Tibiotalocalcaneal arthrodesis with a fibular strut autograft has been shown to produce a union rate (81.2%) similar to that of the traditional arthrodesis technique with intramedullary nailing (74.4% to 90%). The strut graft provides an osteoinductive environment for healing and increases the post-arthrodesis load tolerance¹. Mean visual analog scale pain scores improved from 6.9 preoperatively to 1.2 postoperatively with use of this procedure¹. The most common complication was wound dehiscence requiring additional wound care (37.5%); its rate was higher than the rates reported in other studies of tibiotalocalcaneal arthrodesis, possibly because of the small sample size of patients undergoing such a complex procedure for a complex medical issue^2,11. Although 7 patients required a reoperation, all ultimately experienced a union and recovered postoperatively. All non-retired patients were all able to return to work¹.

Important tips: Place your incision precisely to allow adequate exposure of both the tibiotalar and subtalar joints.Curvilinear incision should begin 6 to 8 cm proximal to, and directly lateral to, the distal end of the fibula. It should continue posterolaterally to the fibula distally and extend inferiorly and anteriorly over the sinus tarsi, toward the base of the 4th metatarsal.Prepare the tibiotalar and subtalar joints this same incision.Decorticate the fibular strut autograft; this plays a key role in obtaining fusion.Harvest the fibula 6 to 8 cm above the ankle joint line. Once the graft is harvested, smooth the edges of the fibula with a burr; this facilitates graft insertion.Finally, when immobilizing the joint, take care to avoid excessive perforation of the graft as this increases the likelihood of fracture.

Acronyms and abbreviations: OR = operating roomIM = intramedullaryCT = computed tomographyTTCA = tibiotalocalcaneal arthrodesisTTC = tibiotalocalcanealK-wire - Kirschner wire.