Osteoarthritis of the ankle joint (ankle joint prosthesis, artificial ankle joint replacement)

Osteoarthritis of the ankle joint, often as a result of previous injuries, leads to progressive cartilage wear and the associated pain and functional limitations. In cases of advanced cartilage damage and considerable suffering, the use of an ankle joint prosthesis can significantly alleviate the symptoms and improve quality of life.

The implantation of an artificial ankle joint is now carried out after precise planning based on a computerised tomography (CT) scan of the ankle joint. This imaging examination makes it possible to analyse the bone structure and the extent of osteoarthritis with millimetre precision. Based on this data, the prosthesis manufacturer produces customised guide templates that define the exact saw cuts on the bone. By using these templates, the bone cuts are made with millimetre precision in accordance with the previously created planning.

Figure 1-4 (from left to right):

  1. Anatomical representation of an arthritic ankle joint in frontal view, based on the CT image
  2. Placement of the patient-specific guide templates for exact realisation of the planned saw cuts on the bone
  3. Carrying out precise bone cuts according to the template guide
  4. Computer-aided planning of prosthesis positioning in the ankle joint

In a second step, the ligament tension of the ankle joint is balanced during the operation so that the joint is evenly stabilised by the ligaments throughout the entire range of motion. This step is called «ligament balancing». I have published a paper, which received an award from the American Orthopaedic Foot and Ankle Society, examining the ligament tension of the individual ligaments in the rearfoot and midfoot, thus providing fundamental information for ligament balancing during the insertion of an artificial ankle joint.

Merian M, Glisson RR, Nunley JA
Ligament balancing for total ankle arthroplasty: an in vitro evaluation of the elongation of the hind- and midfoot ligaments.
Foot & Ankle Int. 2011; 32(5 Suppl): S457-472.
DOI: 10.3113/FAI.2011.0457 PMID: 21733454