On Bended (Robotic?) Knee

Robotic Partial Knee Resurfacing Q&A on the RIO System by MAKO Surgical/Stryker Corporation (Revisited)

The MAKO robotic partial knee resurfacing technology has been FDA approved since 2005 and the first procedure was performed in 2006. The current MAKO RIO system which is a physician-guided robotic system that uses fiducials, bone-anchored surgical reference markers, to guide surgeons in the controlled resurfacing of the knee was FDA approved for partial knee resurfacing in 2008. In 2010 the FDA approved its use for total hip arthroplasty.

Two years later, in 2013, MAKO Surgical was acquired by Stryker Corporation which received FDA approval for the MAKO robotic system to be used in total knee reconstructions in August 2015.

We first sat down with Certified Orthopaedic Assistant and Licensed Surgical Assistant, Michael McHann, OA-C, LSA from the Center for Orthopaedics and Sports Medicine in Tomball, Texas for a Q&A about robotic partial knee resurfacing in November, 2015 to discuss this new procedure. Now that a couple of years have gone by, we are once again sitting down with Michael McHann to gain insight on how this technology has been received, and the impact it is having in this space.


Our initial interview from November, 2015


Wayne Adams, BSRT (R) of MD Buyline: How long have you and your surgeon used the MAKO RIO system, and about how many partial knee procedures have you done with this robotic system?

Michael McHann, OA-C, LSA: We did our training in late April and did our first two partial knee replacements in mid-June on the same day. We have done eight medial MAKOplasty procedures to date.

Wayne: Is there a steep learning curve in becoming proficient with the MAKO RIO System?

Michael: In terms of outcomes, there is no learning curve at all. The beauty of this system is that we are able to preoperatively plan our procedure to determine what size implants are needed. Then, in the intraoperative planning, we can manipulate the implants virtually on the navigation system to ensure perfect placement in terms of tracking and tissue balancing before we have resected any bone at all. So we get perfect placement each and every time.

In terms of time, there is a small curve. Becoming familiar with the navigation system and where to take the bone registration points takes some time to become proficient. I have worked with my surgeon for 20 years, and it did not take us long to work together to create a proficient workflow during the procedure. Our last MAKOplasty, we had a 36-minute “MAKO time,” which is the time it takes for us to start with the navigation system until we are done using the robotic arm to resect the bone and done cementing the implants and double-checking our balancing. Of course, it takes a little longer to close the knee, but overall, it was done in about an hour total.

Wayne: Is there a set of criteria that determines whether a patient is a candidate for the MAKO partial knee vs. a traditional partial knee, or is the MAKO partial knee procedure an option for all patients needing a partial knee procedure?

Michael: If the patient is a candidate for a partial knee replacement, then they are a candidate for a MAKOplasty.

Wayne: In your experience, what are the primary benefits seen with the MAKO RIO System?

Michael: Outcomes, plain and simple. Manual partial knee replacements have high complication rates because of the learning curve involved in becoming proficient. The major factor in partial knee replacement failure is due to poor implant alignment. Independent studies have shown that the robotic-assisted partial knee replacements have two to three times more accurate implant placement and at least three times more reproducible implant placement. The mean revision rate at two years is at 1.1 percent as opposed to about 4.5 percent with manual partial knee replacements. Studies of patient satisfaction rates show, when asked about their satisfaction with the overall function of their operative knee, 92 percent of patients reported “Very Satisfied” or “Satisfied.” We had never included manual partial knee replacements in our practice before because of the learning curve and the lack of volume to become proficient enough to not be doing our patients a disservice. We would have to refer our patients to another surgeon who was proficient and had good results. Now, we have the ability to provide that service to our patients and be confident that we are giving them perfect implant placement and tissue balancing every time. All of our patients that we have performed a MAKOplasty on have been extremely pleased so far. All of them have been performed without the use a tourniquet, and all of them have been discharged from the hospital in less than 24 hours. We had one patient who played 18 holes of golf at six days post op.

Wayne: Are there any drawbacks, or disadvantages to using the MAKO RIO System?

Michael: There really is no clinical disadvantage to using the MAKO system. There is an increase of operative time initially, but the extra time is worth the results.

Wayne: Does the cost to reimbursement ratio make it a viable option for all orthopedic programs?

Michael: The cost of the robot is significant. There is no billable difference between a manual vs. a robotic partial knee replacement. However, in this day and age of outcome-driven reimbursements, I think the cost will be mitigated by the results eventually. Having clinically significant reduction of hospital stays and reduced complications will have an impact at the rate in which the facility can expect to get reimbursed. Facilities with the MAKO robot are also able to market to orthopedic surgeons from other facilities that do not own one, to their hospital, thereby bringing in more volume.

Wayne: What is the view/feedback from patients in regard to being presented with the option of having a robotic partial knee procedure?

Michael: Most patients are excited by the technology and the procedure, itself. They are happy to find out that they will generally have much quicker recovery times and fewer complications than with total knees and are able to get back to normal activities sooner.

Wayne: With the recent FDA approval for the use of the MAKO RIO System for total knee replacements, do you foresee this technology being used for all knee replacement procedures, or will this technology be reserved for a specific patient population?

Michael: I can foresee a day that because of the level of precision a surgeon is able to achieve with his cuts using a robotic arm, that it will become a standard of care. I think that every total knee patient can benefit from the technology. I think that because of the improved placement of the implants, we are going to see the revision rates go down significantly, and patient satisfaction rates will drastically improve. I personally feel that this technology is a game changer for patients and surgeons.

Wayne: To your knowledge, will the robotic total knee system be limited to proprietary MAKO components, or will surgeons have additional component options to choose from?

Michael: As far as I understand, for the information given to me so far, for now, the robotic total knee system will be limited to proprietary Stryker (who owns MAKO) implants. The good news is that as this technology expands, I can foresee a day where other brands may be used. In the MAKO hips, you can use the arm to ream the acetabulum at the ideal angle and anteversion. From there, you can implant any manufacturer’s implants; however, you are unable to take advantage of the technology to preplan the femoral neck cuts and the precision neck lengths that are available to you with the Stryker implants. I think that we will see the hip system to be the first to accommodate other brands. There is also currently work being done to use this technology for other procedures, like ACL reconstructions. I think that the future of orthopedic surgery is very bright indeed.

With today’s healthcare focused on clinical outcomes, faster recovery times and a reduction in redo procedures, robotic systems like the MAKO RIO are paving the way for a safer, more accurate way of providing state-of-the-art healthcare.


Our revisit with Michael McHann – August, 2017


Wayne: It has now been nearly two years since you and your physician first started using the MAKO RIO System for partial knees. Has this technology provided a positive enough impact to have made a difference in the way that you and your physician approach these procedures?

Michael:  We have done well over one hundred robotic assisted partial knee replacements during that time.  The technology and our confidence in the system has given us the opportunity to expand our patient selection slightly and still have successful outcomes.  In some cases where we would have normally suggested a total knee replacement to the patient in the past, we have been able to do a partial knee replacement and still get outstanding results.


Wayne: From an outcome standpoint, does this technology continue to provide the results that were initially expected and seen?

Michael: We still get excellent results.  With the exception of a single post op infection, we have not had to revise one to a total knee yet.


Wayne: Have there been any changes in reimbursement for this procedure? Have we reached the point that the cost to reimbursement ratio will allow this technology to be an option for every facility doing these procedures?

Michael: Reimbursements remain the same.  Facilities are beginning to see the value of having MAKO robots as patients and physicians are being better educated.


Wayne: Is Stryker still the only vendor that manufacturers components for the MAKO procedure, or have other manufacturers teamed up with Stryker to offer additional options to the physicians?

Michael:  Stryker has remained the only company providing implants for the MAKO procedures.


Wayne: In closing, can you briefly tell our readers about the additional orthopedic robotic options that are currently available and the impact that these technologies are having on you and your physician’s practice?

Michael: Since we first spoke, we have also been doing robotic assisted total hip procedures.  That has been beneficial in getting precise placement of the acetabular component and restoring neck length.  In April Stryker released the MAKO total knee replacement.  We have done the training course and are eagerly waiting for the facility to purchase the software and arm attachment. The options available for precise bone resection and soft tissue balancing should very positively impact our outcomes and reproducibility.   

Wayne Adams, Consumables Analyst

Wayne Adams joined MD Buyline in 2011 with more than 18 years of experience in the cardiac cath lab/peripheral vascular field.