There are 3 – 4 components of a Knee replacement
- The femoral component
- The Tibial Component
- The Plastic Insert
- Patella button (in some cases)
The outcome and success and longevity will all depend on how the implants are inserted into the knee joint. This will depend on how the surface of the knee joint (Femur and Tibia is cut).
Traditionally and conventionally, most surgeons use Xrays and plan the bony cuts during surgery as a guide and intra-operatively they use Jigs, which tell them how much bone to cut and check alignments of the prosthesis.
This comes with experience. Hence the higher the number of cases a surgeon does the better the success rates and outcomes and longevity.
More recently Patient Specific Instrumented Knee replacements use Pre- operative CT or MRI scans to Print 3D instrumentation / guides. Most of these are made in USA (Patient Matched TKR)
These Guides are Patient Specific and hence Custom Made Blocks, which determine pre-operatively through navigated computer software to determine bone cuts and determine alignment and component sizes (The size of the prosthesis, the orientation and alignment).
The correct size, the right orientation and right alignment means better functional outcomes and success.