Considering Total Knee Replacement
My Knee Hurts—Should I Consider Total Knee Replacement?
The knee is at unique risk for injury and disability throughout life. Especially so in the consideration of the knee belonging to the current or former athletic population. Like all diarthrodial joints, the knee is an articulation of two long bones (the femur and tibia) as well as the mobile articulation of the patella (knee cap). Each of these bones is made up of a hard, cortical exterior shell with a more porous cancellous interior and its articular surface (the end of the bone which contributes to the joint) is covered with a slick but perishable covering of articular cartilage. It is this articular cartilage that is most at risk for the effects of activity (and hyperactivity), including bruising, abrasions, chips, cracks, delamination and ultimately the osteoarthritis that make up the wear and tear that can result in the eventual need for knee replacement.
The painful knee can result from use, abuse, or overuse. Pain that goes away with rest may be nature’s way of addressing with the knee’s owner that a particular activity may need to be avoided in the future. Over-the-counter (OTC) pain medications are most commonly found in the form of “NSAIDs” (non-steroidal anti-inflammatory drugs), and these can help to abate the pain of an angry knee more rapidly than time alone. Ice also can be an often understated treatment for reduction of the swelling and pain associated with knee pathology.
When rest, ice, and OTC medication fails to resolve the discomfort of knee pain, it is time to turn to a physician for evaluation and management. Persistent pain can not only be troublesome, but it can herald a more severe problem than a simple sprain or strain. Ignoring these symptoms can even place one at risk for ongoing and avoidable additional damage.
At the Doctor’s Office
The best doctors listen. In medical school, a history and physical receives a great deal of attention as one of most useful tools in diving the underlying problem and the means to avoid further damage or address irreversible damage already done. Unfortunately, we physicians lose that lesson in a busy practice and surgeons even more so. But inherent in a thorough history is taking the time to listen; listen to when the pain started, to what makes it better or worse, to what has been tried so far with success, what has failed to help, and anything additional that might provide this highly trained detective in finding the underlying issue so that it can be addressed the in the most efficient manner possible.
Following the discovery phase (the history) comes the physical exam. Moving the knee through its range of motion, looking for limitations or inconsistency with a normal knee. Swelling, clicking, laxity, topical rash can all indicate differing sources of pathology to be discovered. Examination of the nearby muscles, motor and sensory innervations, and even other joints can offer clues to the attentive diagnostician.
Plain X-rays of the joint are an invaluable tool to gain insight (pun fully intended) into the health of the joint. X-rays allow the surgeon to look into the joint without ever having to undergo surgery. They offer clues as to the integrity of the bone that makes up the joint surface as well as the long bones that contribute to the joint. The surgeon can estimate the amount of articular cartilage remaining on the joint surface (the tread left on the tire) and formulate an estimate of what, if any, surgical intervention stands to offer benefit for the pathology at hand.
Options Available to the Orthopedic Surgeon
So what can the surgeon do to relieve the pain? He or she has a number of options. Probably the most commonly encountered insult to a painful joint is simply the truth of being overweight. As Americans, we are an unfortunately obese society. While this can go unaddressed in youth, it often manifests itself as invariable joint pain with time. BMI, or Body Mass Index, calculations can be very useful in helping to guide patients back toward an ideal weight whether they be a little or a lot out of bounds.
Activity modification is often the first thing to be addressed. Any repetitive motion stresses such as running or hockey, or any other high-impact sports may finally be catching up with the aging process. Even shoes can be to blame. High heels, for example, have been associated with altered mechanics that increase wear on joints. Simply trading offending footwear in on sensible shoes can offer significant decreases in pain for very little sacrifice.
Prescription pain medication can take the form of stronger NSAIDs than are available over the counter, steroid medications, or any number of prescription pain medications to affect various instigators of the pain response. These are all tailored to surgeon experience and patient specifics regarding allergies, comorbidities (other disease states), or medications tried with or without benefit up to this point.
Physical Therapy (PT) is another option available to the surgeon. A prescription for PT can be pertinent in the rebalancing of the painful knee in order to unload a problematic component of the joint and/or strengthen the important muscles around the joint to improve tracking of the patella and subluxation of the femoral component of the knee on the tibial component.
Depending on the pathology diagnosed, injection may be appropriate. Hyaluronic acid injections have proved beneficial in tamponading the effects of early arthritis in some patients and can help to put off the eventual need for knee replacement, or even act as definitive treatment for those patients with advanced degeneration of the knee for whom knee replacement may not be appropriate because of excessive body weight, comorbidity, or other complicating factor.
Steroid injections are another option available to a patient with a painful knee. Unfortunately, patients are commonly encountered who has previously received one or more possibly premature steroid injections by a well-intentioned healthcare provider prior to referral to an orthopedic surgeon. Steroid injections certainly are a powerful weapon to relieve knee pain, but their effects can be short lived in some patients. Additionally, the lidocaine (numbing agent) often combined with the steroid can actually have detrimental effects on the remaining articular cartilage, especially if the injection is given too many times or too often.
PRP (platelet-rich plasma) injections are one of the most interesting new discoveries in the emerging field of biotherapeutics. Platelets are naturally occurring components of a patient’s own blood. Platelet activation has long been acknowledged as an important component of wound and soft tissue healing. An orthopedic surgeon has the ability to extract a patient’s blood in the office, concentrate the plasma and healing factors by spinning the blood in a centrifuge, and then injecting this concentrate into the knee joint in an effort to capitalize on the potential healing capacity for the injured or diseased articular surfaces. The knowledge base on the ability of PRP to address a variety of intra-articular pathology represents truly cutting edge, developing science, and holds the potential for great advances in the non-surgical treatment for the damaged knee joint.
It may surprise one to learn that surgery is only one of the tools available to the surgeon. The specialized training that goes into the knowledge of how to treat surgically is equaled in importance only to appreciating WHEN to turn to surgery as an alternative. Arthroscopic surgery refers to the minimally invasive option of creating a number of relatively small incisions in order to look at and ultimately address pathologies identified within an injured or diseased knee. It was only in 1982 when a Japanese surgeon first discovered its potential. Dr. Watanabe used a small camera attached to a wand, intended for visualizing the bladder, into a knee joint and was able to visualize the inside of the joint; and arthroscopic surgery was born. Today, meniscal cartilage tears, articular cartilage defects, and even loose bits of cartilage and/or bone that can cause biomechanical locking, clicking, or pain can be addressed arthroscopically. An arthroscopic knee procedure is often conveniently carried out as a day surgery, where the patient leaves the hospital a few hours after the procedure is performed and follows up in a week or two in the surgeon’s office.
At the end of the proverbial rainbow, of course, is the ability to replace the surface of the diseased or injured knee joint through a partial (unicompartmental) or total knee replacement. Reproducible total knee replacement surgery was developed only in the 1970s. Literally, everything learned about successfully replacing the human knee joint has taken place over a single lifetime! Today, over 600,000 total knee replacements are performed in the United States each year, and by the year 2030, estimates are that the number is expected to be approaching 3.5 million annually. So many, in fact, that estimates are for the number of knee replacements will soon outpace the ability of available orthopedic surgeons to replace all those knees.
A Final Word
Any painful joint represents a life not fully enjoyed. Often, a painful knee can be a simple reminder of what we already know; that we’re doing something we shouldn’t be doing or else doing too much of it. OTC medications, rest and ice are available for home remedy and are often beneficial. Persistent pain, on the other hand, calls for an expert evaluation. The orthopedic surgeon is uniquely equipped to discover and treat the entire spectrum of knee pathology to keep you and your knee active, happy, and pain free.