[ed. note: Michael Jorrin, who I like to call Doc Gumshoe (he’s a longtime medical writer, not a doctor), writes for us on health and medical issues from time to time — his articles generally are not financial in focus, but he has agreed to the same trading restrictions as our other authors, and, as with all contributors to Stock Gumshoe, he chooses his own topics and his words and thoughts are his own.]
In the most recent Doc Gumshoe piece, I let everybody know that there would be a hiatus in these communications, since I was shortly going to swap my creaky, achy, worn-out right knee for a nifty new one made out of titanium. I promised to keep you posted on how the whole thing went, since it’s possible and even likely that quite a few denizens of Gumshoe Republic are considering doing the same sort of thing.
Before I get into this thing, let me say at once that every aspect of my procedure, from the consultations with my physicians prior to surgery right through to the rehabilitation process – which I’m right in the middle of, and will continue with for some time to come – has been unqualifiedly excellent. I won’t name names or identify institutions, but if anyone wants a specific recommendation, I’ll be happy to do it off line.
An aspect of total knee replacement – we’ll call it TKR going forward – is that the procedure and the aftermath touch on a lot of issues that affect many people in many different ways, ranging from the conditions that lead up to the need for TKR, to the hazards relating to the procedure and how to minimize these, to issues relating to pain management and the potential for opioid addiction, and finally what to do to get the most benefit from the procedure, involving rehabilitation and physical therapy.
The most common antecedent to TKR is osteoarthritis, which is tantamount to saying that I swapped the old knee joint, which was pretty much worn out, for a new one. The implication of the worn-outness of old joints goes beyond “mere” pain. What people tend to do when their old joints get stiff is try not to stress the joint too much. They (and that definitely included yours truly!) don’t bend the joint as far, and also don’t straighten it out as much. As a result, when we walk, instead of putting our heels down first, as normal folks do, we tend to put our toes down first and sort of scuff the heel, which is not good. Sitting down on chairs that are too low can be tough; if the chair has arms, we push ourselves up until we can get our legs comfortably underneath our bodies for that upward push. Squatting is torture. Getting in and out of our canoe was a feat, and the only reason I managed to do it at all is because I’m truly pigheaded.
Osteoarthritis is not the only reason people get knee replacements. Some people with rheumatoid arthritis wind up getting joint replacement, although the joints affected by RA are more often upper body joints. And sometimes an accident can lead to TKR. But mostly it’s OA.
For a start, here are some fairly recent statistics about TKR, most of which I didn’t know about until I did some sleuthing around.
- Since TKR was introduced in the US in 1971, 4.7 million persons have had this procedure, 3 million of whom were women (and, therefore, 1.7 million were men.) The excess in the number of TKRs in women probably has something to do with low bone mineral density in women.
- In the year 2010, 719,000 persons had TKR, compared with 332,000 who had total hip replacement.
- The average age of persons having TKR is 70.
- The success rate for TKR, both in terms of significant pain reduction and significant improvement in mobility, is quite high. More than 90% of patients report being highly satisfied that they had the procedure.
- The rate of significant complications – particularly blood clots and infections – is low, around 2%.
- There is significant regional variation in the frequency of TKR. The procedure is twice as common in the south, where 37.8% of these procedures are carried out, than in the north-east, where 16.6% take place. A possible reason for this disparity is that more people in the south have osteoarthritis related to overweight.
- The TKR prosthesis does not last forever. The articular surfaces of the new joint will experience some wear, depending on the individual’s level of activity. However, in most cases, even when the prosthesis itself shows signs of wear, it doesn’t need to be replaced – a much simpler surgical procedure can restore the original prosthesis to normal function.
How it all started: first, my left knee
It was about six years ago that I started to have a problem with my left knee – pain and stiffness, particularly during and after long car rides. Heeding the firm advice of my wise and loving spouse, I consulted an orthopedist (whom she had also seen). The first thing this guy spotted was that I have a scar just below my left knee cap. What the heck was that?
That scar marks where I came down hard, knee first, on a sprinkler head, playing football in the front yard of a friend, when I was about 12 years old. My mother took me to our family doctor, who poked around (having given me a shot to quell the pain, which was considerable) and determined that I had significantly nicked my anterior cruciate ligament. I had never heard of the ACL at that time, and neither had my mother, but our excellent doctor told us that it was not an uncommon injury, and that he could trim off the torn parts, stitch it together, and have me pretty well back to normal in a couple of weeks, although I was sternly told not to play football and in general to take it easy on that leg. The major consequence at that time was that I couldn’t ride my bike to school and had to take the bus like a sissy.
Now, many decades later, my orthopedist thought it was unlikely that I would only now be experiencing the consequences of my injured ACL, but he ordered an MRI just to check what might be wrong. What the MRI discovered was that I had a severely shredded meniscus in that knee. The orthopedist did not think that laparascopic surgery to repair the meniscus was likely to result in much improvement, because there wasn’t much meniscus left to repair. For a start, he gave me an intra-articular (meaning, into the joint space) steroid shots – prednisone, to be exact – and, starting about two or three days after the shot, the improvement in my knee was considerable. I went back for more prednisone shots every six months or so, and this regimen permitted me to do whatever I wanted to do. That is, until it didn’t.
The next step: hyaluronic acid
We then moved on to hyaluronic acid, in a preparation trademarked as Euflexxa. Hyaluronic acid occurs naturally in the body, particularly in the eyes and the joints. The source of hyaluronic acid for therapeutic purposes is usually rooster combs, but it can also be created artificially by enlisting certain specific bacteria. The outer coatings of some cocci are especially rich in hyaluronic acid; this can be harvested and put to good use.
The FDA has approved the use of hyaluronic acid during certain eye procedures, including cataract removal, corneal transplantation, and repair of some eye injuries. It is injected into the eye during the procedure to help replace natural fluids.
As an ingredient in several supplements, hyaluronic acid can be taken by mouth, supposedly to counteract the effects of aging skin. Evidence for its effectiveness for this purpose is sketchy, to say the least.
Injected into the joint space, hyaluronic acid works as a lubricant and a cushion, in part replacing the cushioning effect of the abraded meniscus. There is good evidence that intra-articular hyaluronic acid can delay the necessity of knee replacement by several years – enough so that Euflexxa is specifically FDA approved for osteoarthritis of the knee, and so that many insurers will cover the cost – but only after the steroid shots stop working.
I received my Euflexxa shots – it’s a series of three shots, about a week apart – almost four years ago, and the left knee has been mostly okay ever since.
But then, about a year and a half ago, the right knee started causing problems.
The story of my right knee
The orthopedist wasn’t surprised that trouble should have descended on my right knee. Both knees had been X-rayed when I first presented, and in both knees the joint space had narrowed to the degree that looming troubles could be predicted. He also assumed that we would treat the right knee much as we had treated the left knee – prednisone first, then, if and when the prednisone stopped being effective, moving on to the hyaluronic acid.
It didn’t work out that way. I got a prednisone shot in October, 2013, and it provided no relief. The knee was stiff and painful, and simple actions like sitting down in a chair with no arms – and then getting back up out of that chair – proved increasingly difficult. Choir rehearsals were a trial, because our music director keeps telling us to stand up and sit down. Singing Bach and Brahms were compensation for this torture.
After the wait imposed by the insurer, we moved on to hyaluronic acid with, again, no benefit. At that point, early 2014, TKR seemed the only option. But then I recalled another knee-related affliction that might be involved.
I remembered that I had a bone spur – an osteophyte – just above my right knee. It was discovered during a physical examination when I was being inducted into the U. S. Army. I had enlisted, just after graduating from college, not out of a particular sense of patriotic duty, but because it was that or be drafted, and enlistment led to better opportunities in the service; also, if you enlisted you knew well in advance the date you were to report and didn’t have to wait around for the notice from your draft board.
But it was not meant to be. In the course of the physical, the examining physician gave my right leg a vigorous squeeze, just above the knee. I jumped through the roof. I was then put behind a fluoroscope, which is a type of X-ray machine that gives an immediate image on a screen, much less used today than formerly because of the high radiation doses they employ. The fluoroscope revealed the bone spur, jutting up into the quadriceps muscles like a skeletal finger.
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That was it for my military career. The representative of the U. S. Army told me to go home. If my bone spur were to cause me any serious problem during my time in the service, the Army would have to compensate me for disability, and Uncle Sam didn’t want to risk the expense.
The question now, several decades later, was whether the bone spur – after not bothering me for all those years – was now finally acting up. My orthopedist thought likely not, but best to rule it out. The procedure of choice for this was to give me ultrasound-guided steroid injections at the site of the bone spur.
Once again, no benefit ensued. The choices had once again narrowed, and TKR loomed. But first, to satisfy the insurer that all possible options had been explored, another series of hyaluronic acid injections was scheduled and carried out.
This time around, I thought that I detected some benefit, at least in the first few weeks after the injections. The question was whether I was being honest with myself, or just pretending that the knee was better to avoid facing up to TKR. However, my perspicacious wife pointed out to me that doing routine stuff, like getting into the front seat of the car, was causing me more and more trouble as time went on. So TKR it would be.
The orthopedist I had been seeing is not himself the surgeon, but he referred me to an ace in his practice, with whom I made an appointment. This excellent fellow was candid: I had put off doing this thing quite long enough. We scheduled the surgery for April 7th of this year. My wife and I sang our last concert of the season, celebrating the 90th birthday of our choir. I cooked several tasty dishes to put in the freezer, treats for when I came home. I told Gumshoe denizens not to look for anything in April, and into the hospital I went.
It’s difficult not to feel that the procedure itself is the least of it. That, of course, immensely undervalues the skill of the surgical team, and fails to take into account the huge gains in experience with doing TKRs in the 45 years since these were first carried out. My surgeon has done many, many, many TKRs, which is what you want, of course. It’s almost routine, but “routine” on an exceedingly high level, like landing a jet plane on an aircraft carrier. Or as Earl Weaver used to say about the performance of his Baltimore Orioles, in the days of their glory, “We do this every day.” My surgeon does TKRs every day, as well as other complex surgeries demanding the highest level of skill and judgment.
What the procedure consist of is sawing through the leg bones above and below the knee joint – the femur, the tibia, the fibula – removing the old wrecked knee joint, inserting and cementing the shafts of the prosthesis (the new knee) into the leg bones, replacing the knee cap, and putting all the muscles back in place. Of course, the muscles have to be separated and pulled away from the leg bones to permit access to the immediate knee joint, and this, without doubt, is major trauma – an “insult to the body,” as they sometimes say. An important part of the procedure is that the tendons and ligaments are left intact. They do not have to be attached to the prosthesis.
Preparing for the surgery is much like preparing for any other major surgery – avoid aspirin and other agents that might lead to bleeding, hydrate copiously, eat or drink nothing after midnight on the day of surgery – all normal preparations. I had a pre-operative once-over with my primary care physician, including chest X-ray, blood work, and the usual thumping and prodding. TKR patients are advised – gently – to do some exercises prior to the procedure to build up muscle strength and flexibility. The assumption is that most people who need TKR have been going easy on the bad leg, which leads to a tightening and shortening of muscles and ligaments that we’re going to need later on; this was certainly so in my case.
The anaesthesiologist then comes in and blesses you, making sure that all cardiac and respiratory signs are okay and that you’re in good shape to weather the surgery. At this point, you just go with the flow, and the next thing you know, you’re awake and feeling no pain. A particular feature of the anaesthesia for this procedure is that a femoral nerve block is employed, which means that for at least 24 hours after the surgery, the operated leg is untrustworthy. All the same, the morning after my surgery, nurses came and helped me out of bed and on my feet. I took a few steps, aided by my walker, while the nurses watched like hawks.
Hazards and precautions
Immediately after surgery, and for the next few weeks, the biggest bugaboo is the risk of a fall, which could hugely complicate matters, potentially requiring surgical intervention. At the very least, the pain quotient would rise drastically, and the process of recovery would be seriously set back. One has to be really, really careful. Many post TKR patients are wheelchair bound for the first few days, or even longer. I was lucky, or perhaps just cussed, but I never used the wheelchair. For a bit over a week I got around with a sturdy walker, and then graduated to a cane; now (about four weeks post-surgery) I keep the cane with me, but mostly don’t need it when walking within a room. But I definitely need it going up and down stairs.
The other main hazards are infection and blood clots.
The hospital takes extraordinary precautions regarding infection control. A minimum number of people are in the OR, and the air pressure in the OR itself is such that when the doors are opened, air flows out of the OR rather than into the OR. I had to use specially-treated cloths to clean my right leg, both the evening before surgery and the morning of surgery. Then, prior to surgery, the whole leg is disinfected once again.
Infection control is particularly important when a prosthetic device is being implanted. Even though the new knee is made of titanium, which is highly resistant to corrosion, the body recognizes that the prosthesis is a foreign intruder. The body’s response to the presence of this invader is to coat the prosthesis with a biofilm, which consists of cells that normally inhabit the body. The biofilm in turn creates a habitat for bacteria. Infections anywhere in the body can seek out and colonize this habitat.
The need for measures to prevent infections goes way beyond the surgery itself. Post TKR, any surgical procedure, no matter how minor, requires prophylactic antibiotics. For example, the next time I have my teeth cleaned (and from then on), I will take prophylactic amoxicillin in advance.
Although prior to surgery it’s important to avoid anything that prevents blood clots (such as aspirin) and that therefore might promote uncontrolled bleeding, once the surgery has taken place, the priorities are totally reversed. Now blood clots, especially of the type termed “deep venous thrombosis” or DVT, become major threats. Large blood clots tend to form naturally in the surgical area as a result of impeded blood flow in the veins. If a big clot became detached, it could travel to the lungs and cause a pulmonary embolism, preventing oxygenated blood from being transported back to the heart for recirculation to the rest of the body. Smaller clots could cause problems of varying degrees of severity in other parts of the body.
Clot prevention starts immediately. The operated leg is placed in a device that continually flexes it, keeping the blood from pooling in the veins. This goes on for a couple of days, and in my highly sedated state, I was hardly aware of it. I also was given enoxaparin (Lovenox), a medication that effectively blocks two of the 13 blood clotting factors. Lovenox is a low-molecular-weight heparin, given subcutaneously. It has at least one important advantage over warfarin (Coumadin), which is the anti-clotting medication commonly given to persons with atrial fibrillation as a means of avoiding strokes. Lovenox does not require blood monitoring for prothrombin time, an indication of how long it takes for blood to clot. Subcutaneous Lovenox continues for about two weeks post surgery, and it is really easy to self-administer. You just pinch a bit of stomach fat (yes, I have a tiny bit of stomach fat), stick in the needle and press the syringe. There is no pain whatever, and not even a droplet of blood.
As part of the clot prevention regimen, I have to wear a compression stocking on the operated leg for about a month after the surgery, which is a bother. This provides a little mechanical assist with venous blood return, preventing the blood from pooling in the veins. It may also help a bit with reducing the inflammation.
Pain management and the risk of addiction
Yes indeed, there is pain. Persons undergoing TKR will be asked, over and over again, what is the level of their pain on a scale of zero to 10, where 10 represents the worst possible pain. The joke, if you can call it a joke, is that 10 is the usual pain level that TKR patients experience. Actually, I don’t quite see it that way. Perhaps I have been lucky in my life that I have not had prolonged periods of extreme pain, but I have certainly experienced severe pain. However, it strikes me that the pain experience has a number of different dimensions.
For example, there was that time I picked up the roaster with the turkey in it, straight out of the oven, with the mitten on the wrong hand. This was agonizing, searing pain, for just a few minutes, until I ran cold water on it. But my dominant sensation was that I had just done a really dumb thing. I may even have laughed at myself for being stupid. It didn’t feel threatening.
If I had felt pain somewhere in my body cavity similar in intensity to that burn, or to the pain in my knee, I would have taken the pain to mean that something was seriously amiss, and I would have been deeply frightened. But with the knee pain, I know where the pain is, and why I am in pain, and I know that it will diminish over time. And, maybe most important, I know that I am experiencing the pain for a purpose, that being to recover the function and mobility that I have lost as my poor old knee wore out. So I am able to distance myself from the pain, which makes it easier to manage.
Of course, there was pain medication. Initially, in hospital and at the rehab facility, nurses came around with little plastic cups containing quite a lot of medications. The principal pain medication was (and is – I’m still on it for a few more days) oxycodone, an opioid. At the start, I got the oxy every three hours including one dose in the wee predawn hours. Over the days, the frequency of the doses diminished, and by the time I was discharged from rehab, I had to ring for the oxy, and was down to about five doses per day, 10 mg per dose. I am now down to one dose per day, at bedtime.
In hospital, I was also given acetaminophen, three 325 mg tablets, four times per day, for a bit under the 4000 mg maximum dose. I stopped this during rehab, since my personal experience with acetaminophen (supported by recent trials) is that it doesn’t do much for pain associated with arthritis. I think the rationale is that it addresses pain through a different mechanism, thus perhaps adding to the pain relief activity of the oxycodone. And I was also given (and will continue to take for another few days) meloxicam, an NSAID, not primarily for pain relief, but to diminish the inflammation that still affects the bad leg.
(By the way, the pill regimen in hospital and also in rehab included a bunch of other medications and supplements – vitamins, calcium, a stool softener. Valium (for anxiety) and Ambien (in case of insomnia) were on offer, but I didn’t need those. And I’m now back on aspirin 325 mg per day.)
Oxycodone is potentially addictive. It is a semisynthetic opioid, available in two formulations – an immediate release version, which is the one I was prescribed, and a controlled release version, which slows the absorption of the active drug by encasing particles of the drug with a coating that delays the drug’s solution. Individuals who are looking for a rush, or a high, mash up the controlled release version to overcome the delaying activity of the coating. Alternatively, they dissolve the tablets in water and inject the solution. Oxycodone is also available as Percoset, compounded with acetaminophen, which, along with providing some pain relief (limited, as I said above), also inhibits the cannabis receptor, which may result in damping the high that the opioid might produce.
Patients with post-surgical pain do not usually experience a high with oxycodone; however, they can become addicted. The mechanism appears to be a build-up of tolerance for the drug as the pain receptors are primed to detect lower levels of pain. Some post-surgical patients want to achieve the same virtually pain-free level that they experienced immediately after surgery, and want to increase their intake of the pain medication until the pain disappears. This doesn’t happen frequently, but it does happen. At this point, I can say, with a high degree of confidence, that it’s not going to happen to me.
Onwards to the rehabilitation phase
The objective of the whole ordeal is to recover the capacity and mobility that you had before the knee began to wear out. The surgery, and the prosthesis, deals with the failure of the old joint, but it doesn’t do a thing for the adverse changes in the muscles and ligaments that have taken place as accommodation to the stiff, incompetent old joint. That’s the job of physical therapy.
For me, physical therapy began in hospital the day after the surgery. The therapist, a brisk-but-kind young woman, had me out of bed, walking a bit with my walker, and starting the program both of straightening out my leg and bending the knee joint. Because of favoring the old joint, I could no longer completely straighten out my right leg, nor could I, on my own, bend it to any more than a 90⁰ angle, at most. The ultimate objectives are to straighten the leg completely and also be able to bend it to an angle that they call 110⁰. (In geometry class, this angle, an acute angle, would have been called 70⁰, but no matter, the physical therapy community has its ways.)
After my three-day hospital stay, I went to a residential rehabilitation facility, where the physical therapy continued at a stepped up rate – morning and afternoon, under the supervision of a chap I called Lorenzo the Magnificent, who had a Medici-like appetite for submitting me to torture. The physical therapy consisted of a variety of exercises, all with the objectives of bending and straightening the leg, and also strengthening the muscles, particularly the quadriceps. Without question, this was painful – remember that the quads had been manipulated considerably during the surgery, and that while he was at it, the surgeon also had to get in there to cut out my notorious bone spur. By the time I left the rehab place, after 12 days, the knee bend had reached 108⁰, with Lorenzo pushing with all his might and main.
At this point I am continuing with out-patient rehab. My knee bend is currently about 106⁰, but the therapist (the Cruel Christina) isn’t pushing me nearly as hard as Lorenzo. The deviation of my leg from the straight angle, with just a bit of pushing from Christina, is about 6⁰. She’s confident that we’ll get those measurements to 115⁰ and 0⁰ before I’m declared at liberty.
So, what’s the conclusion?
I was told by my surgeon that at the two-week past surgery point, many patients wondered why they had submitted themselves to such pain, and that even at the one-month point, many patients were unsure whether they would do it again if they had a choice. But by the three-month marker, the word is, just about everybody is happy that they did the TKR, and most even wish they had done it sooner. For my part, I never had any doubts as to whether I was doing the right thing, and now, about a month out, I have no doubts that when the time comes, I’ll go ahead and do the left knee. Maybe I’m lucky, maybe I just happened to have exceptional treatment, or maybe (as my mother would have insisted) I was born with rose-colored glasses permanently implanted.
I want to thank the Gumshoe tribe for going along with me on this detour into the personal. I ventured on that path in the hopes that it would provide a bit of perspective for people who are thinking about having TKR themselves. I know that when I was facing the prospect, I paid more attention to the personal reports of friends who had experienced the procedure than I did to the literature on the subject.
Many thanks to you all, and very best regards. Michael Jorrin (aka Doc Gumshoe)