Why do nearly thirty million Americans suffer from pain and loss of function due to osteoarthritis (OA) of the knee? The knee joint is not a simple hinge. Knees exist at the epicenter of the Perfect Storm of orthopedic problems.
They are used with
1.) High frequency – knees undergo thousands of movement cycles every day for decades.
2) Under load – unlike elbows or wrists, knees bear the brunt of your body mass and impact associated with walking, climbing, carrying, running, and jumping.
3. Long levers – the knee joint is the longest lever in the body, which amplifies any
imprecision of movement at the foot, ankle, and hip.
If you run, jump, and accelerate a lot, sooner or later this will probably effect your knees.
If you suffer a traumatic hit, slip, or twist of the leg, it’s probably going to effect your knees.
If you have simple tightness at the foot, ankle, or hip, in time this will effect your knees.
If you have weakness at the foot, ankle, or hip, this will gradually grind your knees.
The research clearly shows that those with knee OA suffer a downward spiral of pain, decreased activity level, and general poor health and fragility. “So you better get moving” say the rehab people. “Lose some weight” order the medical people. But moving hurts. Now what?
Beat Up Your Knees-Save Your Knees
Is exercise a cause of or treatment for knee pain? Both! Well, it depends on what kind of exercise. The role of physical activity in causing and treating osteoarthritis has been extensively studied and reviewed. What we know is what you could have guessed.
-Low impact exercise and not being overweight are helpful. Manage your weight and quit doing anything fun.
-Physical therapy (which includes a variety of interventions) is just as effective as surgery in the treatment of meniscal tears and mild to moderate arthritis of the knee.
-If you still have debilitating pain with advanced OA, have stopped doing anything fun, and tried conservative treatments like anti-inflammatory medications and injections of corticosteroids and lubrication, then you’re a good candidate for knee replacement.
-Knee replacements do reliably reduce pain and improve self-reported quality of life in 90% of patients. Yay.
-Knee replacement is a major ordeal. You should expect two or three days in the hospital, unless the new joint gets infected. Then you go home and have at least one month of depression, constipation, restless nights, and increased yelling at your spouse. Oh, and thrice-weekly trips to your physical therapist are always a blast.
New Knee, New You?
Here are a few important pieces of evidence that we probably would NOT have guessed:
-Patients generally plateau in their recovery at nearly six months after surgery. You better have achieved full knee extension (straightening) and flexion (bending) to at least 115 degrees by then.
-Although most patients have much less pain and recover to preoperative levels of strength and range of motion, by about six months after surgery, they exhibit the EXACT same level of functional limitations.
-With or without surgery, those with knee OA function about half as well as people without significant knee pain.
-Two years after surgery, function declines significantly below pre-surgery levels. A new knee won’t keep you from getting older. Sorry.
-“Preoperative level” does not imply good strength. Before surgery, people are painful and weak in the legs. After surgery, they usually have less pain but are still very weak in the legs. It is thought that this strength deficit holds the key to the unfortunate stats below.
-Compared to adults without significant knee pain, those who have had knee replacement surgery exhibit 18% slower walking speed, 51% slower stair-climbing speed, and a 40% leg strength deficit. They report having greater difficulty kneeling, squatting, moving laterally, carrying loads like groceries, exercising and playing light sports, dancing, gardening, and participating in sexual activity.
Don’t ask me! I’m just reporting what the literature says.
What we can gather from all this is that knee replacement surgery helps with pain but not much with function. Some people are content with that. But I work with many people who are considering or have already underwent knee replacement, and are not content to sit on the couch, roll over and die.
The Dark Night of Knee Surgery
Oh, the first weeks after knee surgery. There’s definitely an x factor here, an unknown. The x may have to do with expectations and other deep psychology that’s difficult to quantify. It may have to do with other unmeasurables involving blood chemistry and inflammatory response.
You may be a fit, active, and otherwise healthy adult. But that won’t change how your body handles the pain, swelling, and other miseries due to the controlled trauma of orthopedic surgery. A skilled but mere human subluxed your kneecap, removed the ends of your femur and tibia with a hack saw, jammed a fancy peg into the marrow, added some glue to hold everything together, and stitched it back up.
Despite your neighbors friends uncle who experienced Job level devastation after having his knee replaced, the orthopedic docs are great at selecting appropriate candidates for surgery. The patient satisfaction is above 90%. But knee replacement is a process. In my physical therapy clinic a few weeks after surgery, almost everyone regrets having gone through with it. Their pain rating, on a scale of 1 to 10, is approximately “Go shove that pain scale up your…” By two months from surgery, the same folks are reasonable and tend to forget how difficult the first few weeks were.
How well do you really function after surgery? This depends on number mechanical factors beyond recovering the knee range of motion. What chewed up your knees to begin with? It is highly likely that the imbalances in strength and flexibility and motor control do not go away when you have a new knee.
Nearly everyone with knee pain has to sit on the sidelines far more than they would like, and this has propitiated poor balance and an “I can’t” mentality. After years of pain and surgery, patients are afraid of falling and have no idea what they *can* accomplish and safely build up to doing.
Typical Rehab is Not Enough.
Long after your insurance benefits have expired, and your orthopedic doctor and physical therapist have discharged you with a good outcome (typically based only on range of motion), you still exhibit weakness, stiffness, and poor movement patterns.
|You need more than 2 lb leg raises!|
The literature indicates that leg strength correlated with real world function more than anything else. Pushing the strength training is critical, especially in that first six months after surgery. That means pushing 20 pounds instead of 2. That means achieving great control while walking up stairs even before you have recovered sufficient range of motion to descend stairs well. It means challenging your limits in strength and balance with exercises like progressive lunge variations and steps-ups if you can, rather than 3 sets of 100 leg raises and butt squeezes.
Knee to the Future
How much activity can you get away with after having an arthritic or replaced knee? How long will the replacement last? Orthopedic doctors often warn patients about the lifespan of a replaced knee being 15 or 20 years. But I read and hear varying recommendations. The guidelines are definitely anecdotal. I think there’s more to it than that.
How WELL is the knee loaded? Is the replaced joint getting the appropriate support from above and below? Many of those questions depend on the client more than the actual knee hardware. I do not suggest basketball or parachuting, but joint replacement clients can do a lot more than they would think when they have built a fit and generally robust body.
References are available upon request.