Scandinavian Total Ankle Replacement: The Surgical Technique

Abstract

The Scandinavian total ankle replacement prosthesis was designed in 1978 and has been in clinical use since 1981. The operative technique has remained unchanged throughout the years using an anterior curved approach. The concept is: alignment of the entire foot to a neutral position in the 3-dimensional plane, debridement of the ankle joint including extirpation of the posterior capsule to get a free mobility, and, thereafter, a surface replacement of the joint. If necessary, anatomic ligament stabilization of the ankle joint must be performed. The talus component has medial and lateral wings to cover the medial and lateral talus facets. This is necessary because of the alignment technique-talus sculpturing-by which the talus and the entire hind foot is rotated and tilted into normal position. Apart from giving a vast area for ingrowths of the talus component, this technique is especially rewarding in alignment of varus and valgus feet, because these can be corrected within the ankle mortise. Therefore, supramalleolar and calcaneal osteotomies are not necessary. All cases are in a prospective series with regular follow-ups. From these data, the indications and contraindications have been established. The safe indications are traumatic osteoarthrosis, idiopathic osteoarthrosis, and arthritis forms, that is, rheumatoid arthritis. The main contraindications are: talus necrosis including osteochondritis dissecans (magnetic resonance imaging judgment), very aggressive arthritis forms, that is, psoriatic arthritis, severe arteriosclerosis, and severe osteoporosis, mentally disturbed persons, and persons without motor power over the ankle joint. Survivorship analysis at 12 years shows 95% survival rate for the uncemented, meniscal-bearing Scandinavian total ankle replacement.