The decision to have a stress test is left to the discretion of your cardiologist. Like any procedure, a thorough pre-operative workup is required for your safety. This includes general medical clearance, as well as any specialty clearance that is deemed necessary (depending on any pre-existing conditions). This would likely involve some sort of cardiac workup in the face of known cardiac issues, regardless of age.
Archive for the ‘Knee’ Category
For an elderly patient with known heart blockage, is a stress-test necessary for a micro-invasive hip replacement (SuperPATH)?
Saturday, May 19th, 2012How long do robotic partial knee replacements (MAKOplasties) last?
Tuesday, November 2nd, 2010I 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).
Are your procedures covered by Medicare and AARP Medicare Supplement?
Tuesday, October 5th, 2010Q: Considering your hip and knee surgeries: Are the procedures now covered by Medicare and AARP Medicare Supplement? One article on your website from 2009 said they are not covered by Medicare.
A: Yes, all of my procedures are now covered by Medicare & all insurances in the same fashion as any standard procedure. The article you are referring to is out-of-date, and the coverage issue has been addressed. I am sorry for any confusion.
How do you feel about “rocker bottom” (ie- MBT, Sketcher’s Shape Up, etc) shoes for people with hip or knee issues?
Saturday, September 11th, 2010It really depends on how your body reacts to wearing them. Walking mechanics can vary greatly from person-to-person.
On average, your natural foot position is in a few degrees of “plantar-flexion”, meaning that a slightly raised heel in a shoe’s foot-bed would be the most supportive and natural for walking. Most walking/comfort shoes are designed this way, and you will find most have a 1-2″ heel. This should be the most natural for walking, and the “easiest” on your hip & knee joints for the average person.
The MBT style shoes are designed and marketed as a form of “exercise-in-a-shoe”. They purposely make it harder for you to walk, forcing you to use more muscles than you would naturally during a normal gait. This is done by forcing a slightly lowered heel (sort of a reverse high-heel), a very unnatural foot position for walking. Additionally, most experts agree that very flat shoes (ballet flats, flip-flops, etc), while fine on an occasional basis, are detrimental long-term due to overall lack of support. They lack an adequate heel, arch support and foot-bed. Of course, very high heels may have the same shortcomings for the opposite reasons. Any of these shoes may increase forces across your knees & hips.
Any shoe-wear that changes your natural stride can alter your mechanics around your hip & knee. Whether that hurts or helps your problems depends on how your body reacts to wearing them. It is best to gradually introduce yourself to new footwear, starting with short wearing times and increasing that daily until the desired wearing time is achieved comfortably. This is true of all shoes: from MBTs to flats to walking shoes to the highest stilettos.
A good rule of thumb is this: Listen to your body. If wearing any sort of footwear causes your back/hips/knees/ankles/joints to hurt, then your body is telling you to “back off”. This is nearly universally true for all activities and the human body. The “no pain, no gain” mantra for exercising refers specifically to effort, stretching, muscle fatigue & conditioning. You should not do any activity that increases or causes pain inside your joints.
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, 2010You 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, 2010A 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, 2010Regarding 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”.
What is a “revision” total joint?
Sunday, August 29th, 2010Q: If realistically a total joint replacement can fail over time, what about “do-overs”? Are they possible, and can they be effectively performed?
A: “Do-overs” (commonly referred to as “revisions”) are becoming more routine. Technology, techniques & knowledge are advancing quickly in this realm. For all of my patients receiving a joint replacement earlier than 75 years of age, I try to prepare them for the possibility of 1 or more revisions during their lifetime. More information can be found on my website at http://chowhipandknee.com/revision-surgery.html
The “30 year” total knee
Saturday, August 28th, 2010Q: 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.
Patellofemoral replacement
Saturday, August 28th, 2010Q: One of my colleagues just heard Dr. Chow speak at a conference last week and was very impressed. I am a Physical Therapist who has Grade IV patellofemoral changes bilaterally. Does Dr. Chow do patellofemoral replacments?
A: The quick answer is “yes”: I do robotically-assisted limited patellofemoral (PF) replacements.
To more fully answer your questions: I would need to thoroughly evaluate your knees prior to commiting to a limited PF replacement. The reason is that limited PF disease is not easily corrected. PF replacements, in particular, have a relatively poor track-record in our orthopaedic history. Most joint specialists will recommend a total knee replacement for limited PF arthritis, simply because it is the most reliable procedure for the problem.
There are many more related factors that play in sucessful PF replacements: presence of lateral patellar compression syndrome, a tight lateral PF ligament, instabilty of the PF joint, past PF trauma, past re-alignment procedures, extreme natural knee malalignment, etc… just to name a few.