CRUCIATE RETAINING / POSTERIOR STABILIZED

Cruciate retaining refers to keeping the posterior cruciate ligament. This is the large ligament in the back of the knee that gives the knee the normal roll back while bending the knee. A cruciate retaining replacement keeps this ligament to give the knee support.

Posterior stabilized components are based on removing this ligament and using changes in the components to stabilize the knee and provide the support. There is a great deal of debate as to which one produces the best results. Dr. Allison believes each patient’s anatomy, build, needs, bone structure, and ligament tension is different. Therefore, each patient is evaluated on a separate basis and chosen for cruciate retaining or posterior stabilized based on their needs. No two patients are the same and no one surgery will fit them all. This is the personal attention that makes the difference.

CONSTRAINED

The constrained knee means a more stable knee. When there are ligaments that are missing or are not viable, a constrained knee may need to be placed. Several patients of Dr. Allison have been told that they are not candidates for knee replacements due to highly unstable knees. However, with a constrained knee replacement even an unstable knee can be stabilized and still function well. These type of replacements do tend to wear out more quickly but still have a good life span.

REVISION

When a patient has had a knee replacement and it is worn out or not functioning well a revision knee can be considered. These take a great deal of planning and testing to assure the correct plan of action is taken. A full set of blood test are done and a bone scan is completed as a first step with any patient with a painful total knee replacement. Revisions are considered for mechanical problems such as loosening or poor alignment, or for problems such as infection. When a definitive diagnosis can be found a revision knee replacement functions well.