In this review article, orthopedic surgeons from around the country bring us up to date on the latest research and evidence on the management of knee osteoarthritis in young, active adults. This patient population presents quite a challenge as they want to remain active but may be too young for a total knee replacement.
What are their options? On the conservative (nonsurgical) side is exercise, physical therapy, bracing, medications, and injections (steroids or viscosupplementation). When surgery is needed, arthroscopy, high tibial osteotomy, unicondylar knee replacement (replacement of only one side of the joint), or total knee replacement are the choices.
Treatment is determined by the patient’s age, severity of joint damage, and desired level of activity. Management is different for patients who want to return to sports. Returning to normal activity and sports participation may be more likely after a unicompartmental knee replacement compared with a total knee replacement. Some activities are not advised at all after a total knee replacement, whereas other activities can be a part of patients’ lives with experience.
For example, there are no restrictions on activities like walking, low-impact aerobics, golf, bowling, swimming, horseback riding, and dancing. Rock climbing, soccer, singles tennis, football, gymnastics, jogging, handball, racquetball, and handball are on the no-no list. Activities that fall in between must be done with common sense and experience. The questionable activities include road cycling, hiking, cross-country skiing, speed walking, ice skating, and weight machines.
But let’s back up a bit and start with conservative care. What do the experts have to say about each of these modalities? And what’s the evidence to back up those recommendations? Antiinflammatory drugs are used when painful knee symptoms first start. These medications work to reduce pain and inflammation. They can cause some stomach problems so patients
must be followed closely by their physicians when taking these medications.
Many high-quality studies have confirmed that exercise is helpful in reducing pain and improving function. Muscle strengthening is especially helpful in reducing pain. Aerobic exercise contributes to long-term improvements in function. Of course, these programs only work if the patient does them consistently. Once the exercises are stopped, the pain returns and the patient loses ground quickly.
Knee braces can be helpful for some people. Former athletes who have hurt themselves while in action and who want to remain active may benefit from a knee brace. Patients who benefit the most from knee bracing have arthritis on one side of the joint (unicompartmental arthritis) and don’t want (or are too young for) a knee replacement. Bracing helps redistribute the weight and load placed on the joint so that it isn’t all on one side. This type of biomechanical unloading doesn’t work forever but it can delay the need for surgery while still allowing activity.
There are some studies that support the use of foot orthoses (inserts placed in the shoe to correct leg alignment) for patients with medial compartment arthritis. The medial compartment is the side of the knee joint closest to the other knee. Uneven wear on the joint is caused by misalignment of the bones. Placing a specially designed wedge inside the shoe helps shift the foot and realign the knee. The result is to redistribute weight evenly across the entire
joint and unload the medial side of the joint.
One final conservative management tool available to patients with early knee osteoarthritis is the injection of hyaluronic acid (HA). This substance lubricates the joint and can potentially protect the joint surface. This type of injection has some advantages over steroid injections. There are very few harmful side effects of hyaluronic acid and the results last longer than with steroid injections. Either type of injection is meant as a temporary measure to provide short-term relief from pain.
When patients have tried conservative care for at least six months but without satisfactory improvement, then it may be time to consider surgical management. The surgeon may conduct an arthroscopic exam to look inside the joint and see what’s going on. During the arthroscopic procedure, it’s possible to shave off any loose pieces of cartilage and smooth the joint surface. This type of surgery is called debridement. Surgical debridement is used when the arthritis is moderate-to-severe and has not responded to conservative care.
Studies have been published with results on both sides of recommending/not recommending surgical debridement for knee arthritis. There is some evidence to suggest that in the long-run, results following surgery aren’t any better than with an extended period of time in physical therapy and following a home program of exercise.
Surgeons are unable to predict who might benefit from arthroscopic surgical debridement. Many patients who have this procedure end up having a total knee replacement anyway, so the benefit of the arthroscopic debridement is still questionable. It is clear that certain factors such as smoking, obesity, having osteoarthritis for two years or more, and the presence of bone spurs around the joint contributes to worse outcomes after surgical debridement.
Another surgical procedure that has been used to save the joint is called high tibial osteotomy (HTO). The surgeon removes a wedge-shaped piece of bone from the upper part of the tibia (the tibia is the shin bone). The goal of the surgery is to shift weight off the damaged side of the joint more to the middle, healthy portion of the joint.
The high tibial osteotomy procedure allows patients to remain as active as they would like to be. It also saves the joint and preserves bone for a later joint replacement procedure if needed. In some cases, high tibial osteotomy has delayed joint replacement by up to 20 years or more.
It is not recommended for patients who have a previously damaged meniscus, rheumatoid arthritis, or damage to the other side of the joint. Any of these conditions means that both sides of the joint have a significant amount of degeneration. These patients would be a more likely candidate for a total joint replacement.
And that brings us to the subject of unicompartmental (unicondylar) knee replacement and total knee arthroplasty (replacement). More and more people are benefitting from either of these treatments. Better implants, improved surgical technique, and the results of ongoing studies to guide treatment have helped expand the use of joint replacement.
Placement of a unicompartmental joint allows younger patients to remain active in high-demand activities until such time that a total joint replacement is needed.
For those patients who end up having a total knee replacement, there is evidence now to show that 90 per cent of patients still have good knee function up to 10 to 15 years after the implant was put in. This is called the implant survival rate and is much better now with improved durability of the implants used.
In all cases, patients with knee osteoarthritis are treated on an individual basis. Their goals and expectations are taken into consideration when trying to find what treatment will work best for them. Conservative care is the first
choice. Surgery is delayed as long as possible. But when needed, there are several different choices with good results reported. As a result of improved understanding of management techniques, today’s knee arthritis patient can remain active, even returning to sports or high-demand activities.