A successful total knee replacement procedure depends on positioning of the replacement knee components to most accurately reflect the placement of the original natural joint components. There are three current approaches to this - the conventional procedure (described here), computer assisted surgery (described here) and patient-specific technology.
Also referred to as Patient Specific Instrumentation ('PSI') and 'Patient Matched Technology', the approach involves the creation of accurate 3D models of the joint components needing to be replaced, using information from an MRI (Magnetic Resonance Imaging) scan or Ct scan of the knee joint.
Alignment jigs (positioning tools) are then manufactured which match the patient’s own measurements to ensure that during the procedure cuts to the bones are made accurately prior to the implantation of the artificial components.
PSI is especially helpful in specific circumstances, as it allows a surgeon to assess bone defects and plan aspects of the procedure in advance. It is also helpful where limb deformities caused by trauma are present.
There is some evidence that the technique may reduce damage to surrounding tissue, as no pins or rods (called ‘intramedullar guides’) need to be inserted into the bone, as is the case in conventional techniques.
We will discuss with you the various different approaches to total knee replacement surgery and which approach is most suitable in your individual case.