MAKO Robot-Assisted Patello-Femoral Joint Replacement
The Patello-Femoral Joint (PFJ) is the aspect of the knee formed by the knee-cap (patella) and the femur/thigh bone. PFJ arthritis is wear and tear of the cartilage in this part of the knee. This causes the ends of the bone to rub against one another. This may cause pain and restrict the movement of knee. Patients may experience difficulty in walking, climbing up and down stairs or hills and have difficulty with kneeling, squatting, and standing. PFJ arthritis typically causes pain at the front of the knee. Patello-Femoral Joint Replacement is a procedure to replace the back of the kneecap or patella and is considered when pain is not relieved by conservative (non-operative) treatments.
PFJ replacement is intended for patients who have isolated arthritis of only the Patello-Femoral Joint as it is only this part of the knee that gets resurfaced in the surgery. For patients with more widespread arthritis to other parts of the knee, Total Knee Replacement will likely be a more appropriate option.
Why use MAKO Robot-Assisted Technology?
Overall the Australian National Joint Registry shows that 46.1% of Patello-Femoral Joint Replacements are revised 16 years after implantation. The commonest reason for this is the progression of arthritis to other areas of the knee with some surgeons having a lower threshold to revise the Patello-Femoral Joint Replacement due to the relative ease of doing so. In young patients with isolated PFJ osteoarthritis at Patello-Femoral Joint Replacement is often seen as a means of ‘putting off’ a Total Knee Replacement. Given the results of Patello-Femoral and Total Knee Replacement in younger patients appropriate patient selection for PFJ Replacement is vital. Moreso the patient understand the relative merits of the treatment choice taken. Associate Professor Harvie will explain the pros and cons of each in detail.
Isolated PFJ osteoarthritis is not very common and surgeons are notoriously poor at assessing the accuracy of their bone cuts and positioning of Patello-Femoral Joint Replacements. Bone cuts determine the alignment and function of the implants and poor alignment can result in early implant failure. The MAKO Robotic Arm allows me to precisely and reproducibly place implants exactly where I want with minimal error every time. The Robot also assists me in balancing the soft tissues around the knee throughout the full range of motion preventing overloading of the other parts of the knee.
Detailed data related to MAKO Robot-Assisted Patello-Femoral Joint Replacement has yet to be formally captured by the Australian National Joint Registry therefore unlike with Partial and Total Knee Replacements the short and long term outcome of MAKO Robot-Assisted Technology on outcome remains unknown.
Evidence exists to show patients undergoing MAKO Robot-Assisted Partial and Total Knee Replacement have:
- Reduced soft tissue dissection and injury
- Experience less postoperative pain
- Less post-operative blood loss
- Have decreased opiate analgesia requirements
- Rehabilitate quicker
- Less post-operative stiffness
- Have increased range of movement
- Have a shorter hospital stay
- Higher patient satisfaction scores when compared to other Total Knee Replacement systems.
It is hoped these benefits translate to PFJ Replacement patients but the evidence for this is still awaited.
What does MAKO Robot-Assisted Technology actually do?
Associate Professor Harvie currently performs all Patello-Femoral Joint Replacements using MAKO Robot-Assisted Technology.
This system utilises pre-operative CT scans to form a three-dimensional model of your knee. During the operation, the surgeon collects information about the soft tissue balance of the knee. This information is combined with the CT scan and allows the surgeon to perform a virtual operation on the computer once the optimum position has been ascertained for the femoral (thigh bone) component and the patellar component, the robotic arm is then used to precisely cut the bones and allow exact placement of the implants.
The indications for Patello-Femoral Joint Replacement are not changed by the use of the robot. Accuracy of implantation has been shown to be improved whilst personalising the position of components to the patient’s own soft tissues. This means less ‘cutting’ of tissue, less post-operative pain, and faster recovery.
Will it cost more if I have MAKO Robot-Assisted Technology?
No. The only additional potential cost compared with other technologies is the requirement for a preoperative CT Scan. After negotiation with local providers no patient will be charged any out of pocket costs for these scans.
What are the Risks and Complications?
As with any major surgery, there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages.
It is important that you are informed of these risks before the surgery takes place.
Complications can be medical (general) or local complications specific to the Knee. Medical complications include those of the anesthetic and your general well being. Almost any medical condition can occur so this list is not complete.
Complications include:
- Allergic reactions to medications
- Blood loss requiring transfusion with its low risk of disease transmission
- Heart attacks, strokes, kidney failure, pneumonia, bladder infections
- Complications from nerve blocks such as infection or nerve damage
- Serious medical problems can lead to ongoing health concerns, prolonged hospitalization or rarely death
Infection can occur with any operation. In the hip this can be superficial or deep. Infection rates are approximately 1%. If it occurs, it can be treated with antibiotics but may require further surgery. Very rarely your hip may need to be removed to eradicate infection.
These can form in the calf muscles and can travel to the lung (Pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your surgeon.
Ideally, your knee should bend beyond 115 degrees but on occasion, may not bend as well as expected. Sometimes manipulations are required. This means going to the operating room where the knee is bent for you while under anesthetic.
The plastic liner eventually wears out over time, usually over 10 to 15 years, and may need to be changed. Alternatively the remainder of your own knee may wear out requiring revision to a Total Knee Replacement.
Fractures or breaks can occur during surgery or afterwards if you fall. To repair these, you may require surgery.
The operation will always cut some skin nerves, so you will inevitably have some numbness around the wound. This does not affect the function of your joint. You can also get some aching around the scar. Vitamin E cream and massaging can help reduce this. Occasionally, you can get reactions to the sutures or a wound breakdown that may require antibiotics or rarely, further surgery.
The knee may look different than it was because it is put into the correct alignment to allow proper function.
Your leg will be restored to it’s original length as the deformity caused by wearing of the knee has been corrected.
There are a number of ligaments surrounding the knee. These ligaments can be torn during surgery or break or stretch out any time afterwards. Surgery may be required to correct this problem. This problem is minimised with Robotic Assistance.
Rarely these can be damaged at the time of surgery. If recognized they are repaired but a second operation may be required. Nerve damage can cause a loss of feeling or movement below the knee and can be permanent.
Discuss your concerns thoroughly with your Orthopaedic Surgeon prior to surgery.
Summary
Surgery is not a pleasant prospect for anyone, but for some people with arthritis, it could mean the difference between leading a normal life or putting up with a debilitating condition. Surgery can be regarded as part of your treatment plan it may help to restore function to your damaged joints as well as relieve pain. Surgery is only offered once non-operative treatment has failed. It is an important decision to make and ultimately it is an informed decision between you, your surgeon, family and GP. Although most people are extremely happy with their new knee, complications can occur and you must be aware of these prior to making a decision. If you are undecided, it is best to wait until you are sure this is the procedure for you.