This allows movement on both its surfaces. The addition of this component, though not present in the normal ankle, allows the artificial joints movement to match the normal ankle more closely.
This involves rotation as well as up and down movement (flexion and extension)
This ability to match the normal ankles movement also significantly improves the durability of the joint.
Principle ankle replacement
An ankle replacement works by removing the worn out joint surfaces which are generating the pain and as a result the ankle symptoms disappear. Replacing them with a mobile weight bearing surface means that existing ankle movement can be retained. Adequate muscle and tendon function is required.
Both components have bioactive coatings which encourage the growth of your own bone onto them, forming a natural bond.
When and for whom?
This is a procedure whose indication is chronic severe arthritic pain (as with other joint replacements). It is not a ‘prophylactic’ procedure to prevent the occurence of severe symptoms . The progression of an arthritic ankle is often unpredictable. Generally patients should be over the age of fifty. This relates to probable higher functional requirements in the younger age group and as a result likely reduced longevity of the joint. The age of fifty is not an absolute figure.
This age is not an absolute lower limit. The good evidence on longevity of ankle replacements mainly relates to patients over this age. It is likely that, as with other joint replacements, in younger and more active patients an ankle replacement will not last as long as the quoted figures. An exception to this would be a younger patient with multiple arthritic joints (such as with severe rheumatoid disease) who is likely to have low functional requirements.
As important as age are the functional requirements of any patient. Those in ‘heavy manual’ occupations (builders, farmers, heavy industry workers) who are over fifty are probably better advised for a fusion if they have isolated ankle arthritis.
Improving the RANGE of movement per se is not an indication, though may occur. The pre-operative range is probably maintained. Improved MOBILITY is possible, as a result of the pain free joint.