Robotic Knee Replacement Surgery
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 (http://www.ozorthopaedics.com.au/patient-matched-tkr.html)
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.
Why is Patient Specific Instrumented Knee replacement beneficial?
Even before surgery, the surgeon knows the plan for surgery with the size of prosthesis, its orientation and alignment to make sure the patients knee is aligned well with improved range of motion and hence function.
The Use of the PSI blocks also mean that it is minimally invasive with less soft tissue disturbance and no violation of the bone marrow intramedullary canal as in conventional surgery.
Robotic Assisted Partial or Total Knee replacements:
Patients have a CT scan to determine the architecture of the joint and the Robotic arm is then used to prepare the surface of the femur and tibia.
In order to determine the surface of the joints and improve accuracy, separate pins with probes also have to be placed just above the knee and below the knee through separate incisions.
The Robotic arm is then used to cut the bony surface of the knee joint and the prosthesis then inserted.
- CT scans enable to determine the anatomy of the femur and tibia
- Surgeon can plan surgery with the aid of the computer to determine position of the partial or soon to come total knee replacement components
- The robot in some instances can help less experienced surgeons with preparing femur and tibia
- Preparation time, can be cumbersome and takes up more theatre space
- Learning curve. All Surgical Procedures have a Learning Curve
- Robot Cannot identify soft tissues
- Surgeon will have to abandon operation if there are any failures in the process and move to conventional replacement
There are No convincing studies done yet to prove that robots are superior to standard techniques of an experienced surgeon.
Ultimately no machine can take over the mind and technical skills of a well trained, experienced orthopaedic surgeon.
A recent published (Journal of Arthroplasty) study revealed that:
"Robot-Assisted Total Knee Arthroplasty Does Not Improve Long-Term Clinical and Radiologic Outcomes"
This study compared standard conventional total knee replacement and robotic knee replacement (Robodoc) with average follow up of upto 10 years.
Results: There was no significant difference in clinical outcomes between the two groups and there was no significant difference in complications, including revision surgery, between both groups.
In essence, we are still in the infancy of transition & learning. In the future robotic, Virtual reality and Augmented reality total hip and knee replacements will be taking over.