Archive for the ‘Patient-specific total knee replacement’ Category

How long do robotic partial knee replacements (MAKOplasties) last?

Tuesday, November 2nd, 2010
I really can’t comment on the longevity of our newest-generation partial knee (aka uni-knee arthroplasty, or UKA) implants.
 
Historically, total knee replacements (aka total knee arthroplasty, or TKA) have nearly a 90% survivorship at 10-15 yrs.  Newer-generation TKAs we expect to surpass that, but none of them have been around long enough to say.
 
Historically, UKAs have had only an 80% survivorship at 8-10 yrs, most of the failures likely due to flaws in implantation.  Newer-generation UKAs are still seeing similiar results, but may have a slight improvement to this.
 
Newest-generation UKAs (ie- robotic) are seeing an astounding success in the short-term (3 yrs), with the added new possibility of continued resurfacing of other parts of the knee if they wear out in the future.  Historically, if the partial knee was doing OK, but your arthritis progressed to the other side of your knee, your only option was a conversion to a TKA.  Now, we can reliably implant a new UKA or patellofemoral joint (PFJ) knee arthroplasty to the other portions of your knee to match your original one.
 
So, many robotic, minimally-invasive & UKA surgeons believe that robotic UKAs have solved 2 major issues for failure of traditional UKAs: 1) less-than-perfect implantation and 2) progression of arthritis.  Unfortunately, this technology is too new to tell.  The first one ever placed in a human being was done in 2006.
 
Regardless of the longevity of the implant, you will find that the surgical impact to your knee, and the speed of recovery, is an order of magnitude easier than that of a TKA.  For this reason, many of my patients request a robotic UKA, even accepting the potential for future surgeries (which also exists for TKA).

You said that your anesthesia protocol involved “local & regional anesthesia”. Is this the same as the “twilight-sleep” I got during my colonoscopy?

Thursday, September 2nd, 2010

You will be completely asleep, and you will have no knowledge or recollection of the surgery.  This is far more sedation than your described colonoscopy, but not so much that you would require a machine to “breath” for you.

How long is the recovery from your joint replacement surgeries?

Sunday, August 29th, 2010

A very general guide for all joint replacement is:
- You will continue to improve for an entire year, even if you feel 100% within weeks after surgery.

The following is highly variable, and represents a reasonable baseline.  The recovery can be longer depending on the severity of the disease.  Most of my patients stop their pain medication on the following schedules:
- Total hips in 1-3 weeks
- Partial knees in 1-4 weeks
- Total knees in 2-10 weeks
- Revision hip or knee replacement, too variable to comment

I usually recommend that my patients take 2 months off of work for any joint replacement.  That way, you can always go back to work sooner if you feel like it.  Most of my patients return to work within a few weeks.

How long does a total -vs- partial -vs- revision joint replacement last?

Sunday, August 29th, 2010

Regarding implant longevity, the short answer is: we don’t know.

The point that I need to emphasize is that longevity of an implant is HIGHLY VARIABLE.  It really depends on multiple factors.  No patient is the same, activity levels vary, accidents can happen, and the modes of failure are numerous and unpredictable. 

For total joint replacement, 10-15 years is an often quoted average.  Individually, joint replacements can last as long as only a few weeks to 40+ years.

Revision joint replacements may also last as long, but depending on how extensive the revision is, this can also vary widely, and is less predictable than the original (known as a “primary”) joint replacement.  Additionally, your joint’s function can decrease with every surgery that is done to it, mostly because of scar tissue formation.  This also varies widely.

Partial knee replacements can have the same longevity, but they have a higher rate of revision than total knee replacements at 10 years by most studies. 

Advantages of partial knee replacements are that they are easier & quicker to recover from, they feel more natural, and if/when they need to be revised, chances are high that the revision will recover and act more like a primary knee replacement rather than a revision knee replacement at that time.  Even though a partial knee replacement may be the only surgery you need during your entire lifeitme, one way to view a partial knee replacement is that it may be a way to postpone getting a total knee replacement.  To use dental terms: a partial knee is a “filling”, a total knee is a “crown”.

The “30 year” total knee

Saturday, August 28th, 2010

Q: On TV, they talk of a knee replacement that has a life of 30 years… does yours last that long?

A: First, I must say that I DO use a fair amount of this technology in my practice for my total knees (you will find me on the Smith & Nephew website www.RediscoverYourGo.com), and it IS great technology.  It is not available in the robotic partial knee replacement.  While we hope that they will last longer, most of us feel that most total knee systems will reliably last 10-15yrs under standard use, despite the wear claims.

The “30 year knee” is part of the Smith & Nephew total knee replacement product line.  The specific technology is tradenamed “Verilast”, which is the combination of a specialized ceramic-like metal and a high-density plastic.  Wear-simulator studies have shown a compelling decrease in wear for these 2 surfaces in combination, which is why the FDA has approved the claim “30 year knee”.

However, I am hesitant to make a claim that any total knee replacement will last 30 years.  This technology has not been implanted for long enough for us to know.  Additionally, the wear that we are seeing in the simulator studies is controlled wear, and likely does not truly mimic what happens in the human body naturally.  Finally, the “30 year” claim is for WEAR ONLY.  A knee replacement can fail for a variety of reasons over time (fatigue of the metal, bone loss around the implant, failure of the cement interface, fracture, infection, etc.) that are not related to the materials’ wear characteristics.

Knee replacement -vs- partial knee replacement

Saturday, August 28th, 2010

Q: I would like to know more about your knee replacement techniques.  I am in my mid-50s, and have been told that I have bone-on-bone arthritis in my knee.

A: What I can provide for you really depends upon the location and severity of the arthritis in your knee.  If the bone-on-bone arthritis is limited to 1 or 2 compartments, then you would be an excellent candidate for a robotic partial knee replacement.  This is done minimally-invasively, and the recovery is very fast and natural-feeling.

However, if your bone-on-bone arthritis is in all 3 compartments of your knee, then you would be better suited for a patient-matched total knee replacement.  In this case, I would still provide minimally-invasive surgery, but the recovery time would be longer than that of a robotic partial knee.  Your hospital stay would still likely be only 24-48 hrs

Medical tourism – setting up the visit

Saturday, August 28th, 2010

Q: Do you treat patients from out-of-town?

A: Flying to Phoenix for surgery is not only feasible, but it is becoming routine in my practice.  I have established relationships with local hotels to make this easier.  Once I accept you as a patient, our office will contact you regarding all of the necessary pre-operative steps.  This will involve a visit to your primary care physician to “clear” you for this surgery (this is essential to ensure that your trip to Phoenix is not wasted).  Once you are “cleared” by your local physician, our office will work with you to schedule a surgical and visit date.

Medical tourism – needed information

Saturday, August 28th, 2010

Q: If I am traveling to see you, what information do you need to accept me as your patient?

A: I will need to see 2 main items prior to being able to accept you as a patient:

  1. Imaging – xrays, minimum 2 views (pelvis & lateral views are preferred for hips; ap, lateral & sunrise views are preferred for knees).  Recent MRIs will be necessary for arthroscopic procedures only.
  2. Most recent medical records (history & physical)

You should establish a rapport with my staff prior to your visit.  They will help you get any further necessary items to make your trip as smooth as possible.

Billing & insurance coverage

Saturday, August 28th, 2010

Q:  Is your surgery covered by my insurance?  Does your office verify what is covered by insurance well in advance of any procedures?

A:  We accept all insurances except one access plan called “Care First”.  Our office authorizes all procedures in advance with the appropriate payer.

SuperPATH total hips bill identically to that of a standard total hip replacement with all providers, including Medicare.  Likewise, MAKOplasty knees bill identically to any partial knee replacement, and patient-specific total knees bill identically to that of any total knee replacement.

Any further billing inquiries should be directed to our billing department.  I try to distance myself from the finances for ethical reasons.