Total talus replacement and total ankle arthroplasty after ankle, talonavicular joint arthrosis and aseptic necrosis of the talus. A case report.

Abstract

INTRODUCTION Avascular necrosis (AVN) of the talus presents challenges in treatment. Factors such as patient functional status and other health conditions need to be taken into account. In the past, the standard approach for treating talar AVN focused on arthrodesis surgeries, which could limit movement in the ankle joints. Total talus replacement is a potential solution to alleviate pain and maintain motion range. The emergence of 3D-printed talar implants provide opportunity to preserve ankle joint mobility. Total talus replacement surgery is a procedure that involves the complete replacement of the talus bone in the ankle joint.The surgery aims to restore the stability and functionality of the ankle joint, enabling patients to resume normal activities and alleviate discomfort associated with ankle joint disorders.

AIM OF THE STUDY A 43-year-old patient complained of persistent left ankle pain for several years. Conservative treatment was ineffective. Range of motion for the left ankle joint was 10°/0°/25°. CT scan showed aseptic necrosis of the talus, involving the entire talus. Grade II-III osteoarthritis of the ankle joint and grade IV arthrosis of the talonavicular joint was also present. Calcaneonavicular fibrous coalition was also detected. The ankle joint arthroplastic surgery, with the talus being replaced by an individual implant was set. During the operation, anterior ankle joint arthrotomy was performed, the distal end of the fibula was prepared according to templates, the talus was removed, a special endoprosthesis and tibial components were implanted. The talus component was fixed with a screw through the heel bone. A spacer was inserted. The Achilles tendon was lengthened using the Hooke method. Osteosynthesis was performed to increase medial malleolar stability using two 4.0 mm cancellous screws. The ankle was immobilized in a plaster cast post-operation. Antibiotics and anticoagulants were prescribed postoperatively. No complications were observed post surgery. It was recommended to wear a special orthopedic brace for the ankle for 10 weeks. Weight-bearing begin 6 weeks after the surgery, rehabilitation was prescribed after 8 weeks. After a year, the surgical wound healed, ankle range of motion was 15°/0°/25°, stability was sufficient, and the subtalar and talonavicular joints were immobile. X-ray examination showed good positioning of the ankle endoprosthesis, with bony fusion between the calcaneus, talus, and navicular bones. MATERIALS AND METHODS

CONCLUSIONS Total talus replacement surgery emerges a promising results to ankle joint function increase and pain allevation, presenting an alternative to ankle arthrodesis. This surgical method has shown potential in restoring the functionality of the ankle joint post injury or degenerative conditions.