Update on knee osteoarthritis.

Knee pain related to osteoarthritis (“wear-and-tear”) is extremely common, affecting roughly 30 million Americans. As opposed to the knee pain that nearly everybody experiences after a day strolling through the mall or gliding down the slopes, osteoarthritis is a chronic condition, defined as “pain in and around the knee on the majority of days for at least one month during the preceding year, accompanied by characteristic x-ray changes of degeneration.” I see someone with this kind of knee pain every day. It’s a real problem. People are decidedly unhappy with: “Take some Motrin, put some ice on it, and see your doctor in 2 weeks if it’s not better.”

But let’s be clear: the ER cannot fix osteoarthritis (and neither can anybody else). It is the result of applied forces over time that exceed the body’s capacity for resistance. And just as I am no stronger in the ER than the nurses and techs surrounding me, the bones of the knee are no stronger than the muscles, tendons, ligaments, and cartilage that surround them. This is why weight-bearing exercise is so important to prevent the ravages of arthritis—it strengthens not only the bone, but also the support system surrounding it. But it’s not just about the quadriceps; it’s equally important to maintain flexibility, elasticity, and proper alignment. Stretching is critical as we age and should include the core muscles of the hip, pelvis, and low back, in addition to the traditional muscles surrounding the knee (especially the hamstrings). Yoga and Pilates work wonders here. We’ve all seen those overweight, knock-kneed people waddling through Walmart—no wonder they hurt. Spoiler alert: sedentary lifestyle and excess weight are the leading risk factors for developing osteoarthritis of the knee. Given our culture, it’s not surprising that 90% of people over age 60 have tears of the knee’s inner, shocking-absorbing cartilage (medial meniscus).

Osteoarthritis is primarily a degenerative process—not an inflammatory one—which is why NSAID drugs like ibuprofen and naproxen are largely ineffective. It’s also a stretch to think that taking chondroitin and glucosamine (substrates of cartilage synthesis) increase the density of the cartilage lining the articular surfaces of the knee, but it might be worth a shot if the alternative is a knee replacement. What’s clear is that arthroscopic surgery is of no benefit for either osteoarthritis or medial meniscus tears. It just doesn’t work [for more on why, see my posts: “I’m skeptical about … arthroscopic knee surgery” (10/5/15), and “Update on arthroscopic knee surgery” (10/8/16)].

So, if NSAIDs, chondroitin/glucosamine, and arthroscopic surgery don’t help, what about steroid injections? At least once a week someone comes to my ER requesting a “steroid shot.” When I decline they sometimes think I’m holding out, that I don’t want to be bothered, or that I simply don’t know how to do the procedure, but it’s not any of those things: it’s because steroids don’t work! It has never made sense to me to inject a potent anti-inflammatory agent into a joint suffering from a degenerative process (not to mention that there is little data to support the notion that an injected steroid actually stays where it is injected).

Earlier this year, a paper appeared in JAMA comparing the injection of either a ml of a standard steroid preparation (triamcinolone 40 mg) or a ml of salt water into the knee of 140 patients with documented osteoarthritis. Both patients and physicians were blinded to the treatment received/administered. Injections were given at 3-month intervals over 2 years. Patients were evaluated using previously validated scoring systems for pain, stiffness, function, and overall health. They were also timed on a 20 meter walk and a chair-sit-stand-and-walk test. Everyone showed trivial improvements after the first injection but nobody improved thereafter. There wasn’t even much of a placebo effect. Steroids didn’t help, but may have harmed. In addition to function and pain testing, participants also underwent before-and-after MRI scans to determine the effect of treatment on the structure of the knee. Those receiving steroids had twice the degree of cartilage erosion (0.21 versus 0.1 mm) compared to the saline group. Since cartilage erosion typically precedes bone erosion, this wasn’t a good finding. Conclusion: When injected into the knee of osteoarthritis patients, steroids provide no short-term benefit and likely cause long-term harm. Steroids are out.

 

Reference 1

Reference 1

 

That leaves total knee replacement surgery, in which the end of the femur is removed, the top of the shin bone shaved flat, and the joint replaced with a titanium prosthesis. It’s an amazing, expensive bit of surgery, and for those with severe, irreversible erosion, it likely remains the best treatment option. What concerns me is the concept of “indication creep,” wherein patients with increasingly less severe disease are opting for the surgery. Each year nearly 700,000 Americans undergo the procedure with charges totaling more than $36 billion annually. So, it had better work, right?

 

Surgical components of a total knee replacement.

Surgical components of a total knee replacement.

 

The first good randomized-controlled study regarding surgery versus no-surgery appeared in 2015. The Danish trial, published in the New England Journal of Medicine, randomized 100 patients to either total knee replacement surgery followed by an intensive 12-week rehab program, or the same rehab program without the surgery. Similar to the study noted above, patients were evaluated at the end of 1 year as regards to pain, stiffness, function, quality of life, and return to sports. The rehab program was fairly intense and included twice-weekly exercise sessions supervised by a physiotherapist, educational material, dietary advice, and the use of foot wedges and insoles to correct knee malalignment. Pain medications (acetaminophen or ibuprofen) were allowed at the patient’s discretion. Additionally, patients were allowed to cross-over and undergo surgery if they felt the rehab wasn’t successful. The surgical patients fared better across the board. But it should be noted that the nonsurgical group fared well, too, with 68% (versus 85% of the surgical group) demonstrating a 15% or more improvement in knee function. For the patients enrolled in this study, doing something was a lot better than doing nothing.

 

http://orthoinfo.aaos.org

http://orthoinfo.aaos.org

 

But should that ‘something’ be as drastic as replacing the knee? Results from other studies cite a mortality rate within 90-days of surgery of 0.5-1%, mostly from blood clots, pulmonary emboli, and/or infections, while another 20% of patients have poor outcomes with ongoing pain lasting at least 6 months. Finally, a more recent study published earlier this year found less impressive surgical results when reviewing outcomes of more than 4,000 patients from the Osteoarthritis Initiative database. Their conclusion: “Total knee replacement as performed in a recent US cohort of patients with knee osteoarthritis had minimal effects on quality of life.” Not exactly a ringing endorsement for a major, irreversible surgery. Not surprisingly, results depended largely on the degree of disability going in—those with little disability showed little improvement, while those with severe disability showed large improvement. So, if you’re a 75-year old who has failed rehab and weight loss and still has daily knee pain preventing you from walking to the mailbox then this is the surgery for you; but if you’re a 55-year old who simply wants to keep bombing down those black diamond slopes at Vail you should think again.

 

Screen shot 2017-05-26 at 5.49.52 PM

 

As for me, I have much less knee pain than I did 30 years ago, having even returned to running a couple of half-marathons a year. How did I do it? Three lifestyle changes; I stopped doing the things that were damaging my knee, like heavy, free-weight squats and playing basketball (nobody over age 35 should play this sport unless they’re being paid to do so); I kept my core strong through inline skating; and, most importantly, dedicated myself to a 21-minute routine that combines static and dynamic stretching with yoga and Pilates—it works! For osteoarthritis, prevention is the cure. Maintain a healthy weight. Stay active. Avoid the scalpel.

 

References:

  1. Timothy McAlindon et al., “Effect of Intra-Articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients with Knee Osteoarthritis: A Randomized Clinical Trial,” JAMA 2017; 317 (19): 1967-75.
  2. Soren Skou et al., “A Randomized, Controlled Trial of Total Knee Replacement,” NEJM 2015; 373 (17): 1597-1606.
  3. Jeffrey Katz, “Parachutes and Preferences — A Trial of Knee Replacement,” NEJM 2015; 373 (17): 1668-9.
  4. Bart Ferket et al., “Impact of Total Knee Replacement Practice: Cost Effectiveness Analysis of Data from the Osteoarthritis Initiative,” BMJ 2017; 356: j1131.

4 thoughts on “Update on knee osteoarthritis.

  1. Brother Bob…Happy Memorial Day! I hope you are well. I really enjoyed your article, as I have recently been diagnosed with this lovely ailment. Back in college, while playing hoops, I blew my knee out. The great Rittenauer Health Center didn’t even X-ray me, just gave me crutches and told me to stay off it. I really can’t remember what happened, but somehow rehabbed on my own and I guess survived. About four years late, playing softball, I did it again. That time I got scoped and they just cleaned me out, as I didn’t want the full reconstructive procedure. Had a Don Joy knee brace made and used that to play hoops and softball for many years. Now my knee is bothering me. Especially during golf. Visited the Rothman Institute in the Philadelphia area, got x-rayed and received the osteoarthritis diagnosis. Fun getting old. Thanks for the informative article. +LT. Dave Budney

    • Bold-man, good to hear from you, but sorry that your knees are problematic (whose aren’t?). For additional comments see below.

  2. Bob,
    Great article and very informative. I look forward to more like it.
    Here’s my history. Prior to tearing the meniscus in my left knee 11 years ago, I was running, doing triathlons and skating at a high level. I’ve always stretched religiously and done core strength training and yoga. Following arthroscopic surgery (removed 20%? of meniscus) running was no longer possible and within 6 years skating more than 10 miles was no longer pain free. Three years ago I could barely climb stairs and exersise was basically limited to cycling and swimming. No fluid or severe swelling of the knee, just chronic pain.

    Two years ago I met a rheumatologist (Dr Kirkwood Johnston, Kelsey-Seybold, Houston) who has been giving me quarterly cortisone shots. I get significant relief to where stairs are no longer an issue and I’m back to skating 15-25 miles 2x per week. I’ve ramped up the core strength work and stretch and do yoga daily. I also ice regularly. Am also taking circumin and citracal + mag supplements.

    After 2 years of injections, I still get a good 10 weeks of relief from quarterly cortisone shot (pain increases 1-2 weeks prior to the next shot), but I understand my knee will continue to degrade.

    Can you give me additional specific exercises I can add to my regimen? And I would love to sit down and discuss future options as the osteoarthritis progresses.

    • There are generally 4 categories of patients with chronic knee pain (with a lot of cross-over between them):
      • Those with prior knee injuries. As expected, football and basketball players top the list. According to Dr. Constance Chu, director of the UPMC Cartilage Restoration Center, “After an ACL (anterior cruciate ligament) injury, nobody’s cartilage is normal. Half of the people who tear their ACLs will have osteoarthritis within ten years.” (Pittsburgh Post-Gazette, 10/14/11). Those undergoing surgical reconstruction of a torn ACL have 2-3 times the risk of requiring a total knee replacement down the road.
      • The unlucky. These are people cursed with chronic inflammatory conditions like lupus, rheumatoid, psoriatic, or gouty arthritis. Because these diseases are inflammatory and immunologic in nature, NSAIDs, steroids, and immunosuppressive drugs work. Unfortunately, the same drugs that work for inflammatory arthritis may actually hasten the development of osteoarthritis.
      • Those with malalignment and posture problems. People who are bow-legged, knock-kneed, those with pelvic tilts, ankle pronators and supinators, and those with hip and back problems are all at increased risk for chronic knee pain, as well. Compensatory mechanisms to adjust for an injury in one place work by shifting stress to another. Here is where tai chi, yoga, and Pilates can work wonders. It also pays to have a qualified gait analysis before buying running shoes and being fitted by an expert before buying that $5,000 bike. It’s amazing what proper fitting equipment can do to lower the risk of injury.
      • Those who are overweight and sedentary. This constitutes the majority of patients with osteoarthritic knee pain. In a study of overweight older adults, a 5% weight-loss over 18 months resulted in an average 18% improvement in knee function, while combining exercise with the same weight loss achieved a 24% improvement. Impressively, a pound of weight loss translates to a 4-pound reduction in knee stress. This really adds up. Per mile walked, a loss of 10 pounds translates to 48,000 fewer pounds of transmitted knee stress! [Arthritis & Rheum 2005; 52 (2):2026-32.] By age 65, 80% of Americans will have the tell-tale signs of osteoarthritis when their knees are x-rayed, but that doesn’t mean they will all have pain. Only a minority of those with abnormal x-rays develop chronic pain, usually in combination with other factors described above.

      In your case, Duane, you appear to have traumatic, degenerative, and inflammatory components to your knee pain. It also appears that you’re doing everything possible to combat them. There’s no magic. Regarding supplemental curcumin, there are no randomized controlled trials to show that either turmeric or curcumin work to treat osteoarthritis. The peddling of this spice seems all hype and no substance but, hey, it does make brisket taste better!

      There are very few good trials on the use of knee braces and sleeves, although a decent one from 2015 did demonstrate a significant improvement in pain with a corresponding decrease in knee volume (a marker for inflammation) in osteoarthritis patients who wore a knee sleeve for 6 weeks versus those who didn’t. (Ann Rheum Dis 2015; 74: 1164-70.) The downside to braces has always been the fear that their use reduces the strength of the muscles supporting the knee, but a follow-up study by the same author actually found slight gains in quadriceps strength associated with their use. (J Ortho & Sports Phys Ther 2016; 146: 19-25.) So, sleeves and braces are likely a useful adjunct.

      If your pain progresses despite all that you are doing, there are some promising surgical therapies besides knee replacement that include: autologous chondrocyte transplants (wherein cartilage is harvested from a non-injured site and grown in vitro before being transplanted to an area of injury), and mesenchymal stem cell transplants (similar, but done with harvested stem cells). Another surgery known as osteoplasty has been less successful (the intentional creation of microfractures designed to stimulate local inflammation and chondrocyte synthesis of new cartilage into an area of prior injury). There is also a new type of imaging available at a few specialized centers called optical coherence tomography that is supposed to be 100-times more detailed than plain MRI, so there’s hope. In the meantime, keep doing what you’re doing. See you at the races!

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