total knee replacement/knee arthritis

What is knee arthritis?

Arthritis is a general term that relates to cartilage loss and/or dysfunction within a joint. The most common form of knee arthritis is osteoarthritis, commonly referred to as “degenerative” or “wear and tear arthritis.” It is caused by a combination of genetics, activity level, medical comorbidities, and prior injuries or surgeries. Other causes of arthritis include: post-traumatic (prior injury), inflammatory (such as rheumatoid or lupus), infectious, and osteonecrosis (loss of blood supply to the bone).

Symptoms of knee arthritis

The main symptom of knee arthritis is pain. Pain is generally activity related, meaning the more you do, the more it hurts. However, as arthritis worsens, pain can be present even at rest or at night. Pain can be achy and dull or sharp. Other symptoms include stiffness, swelling, and mechanical symptoms such as popping and grinding. As it progresses, the knee alignment often changes such that patients become either more “bow-legged” or “knock-kneed.” This is caused when arthritis is relatively worse on either the inside or outside of the knee.
Activities that are frequently difficult include walking, going up and down stairs, squatting, pivoting, and kneeling. Symptoms can present in different ways. For some patients, these symptoms slowly worsen over a long period of time. For other patients, the knee functions very well until it eventually and suddenly “flairs up” and becomes very symptomatic over a short period of time.

Knee Arthritis


Diagnosis is based on history, physical exam, and imaging studies. Patients frequently complain of symptoms as discussed above. On exam, patients often limp, the leg may be malaligned, the knee is often swollen, with decreased range of motion, tenderness, and palpable grinding with range of motion.
X-rays show us the condition of the bone. On x-rays, we look for loss of joint space (which suggests that the cartilage and menisci are worn out), bone spurs, and cysts within the bone.
MRIs show us the condition of the soft tissues including the cartilage, ligaments, and meniscus. MRIs are not typically needed for routine evaluation of knee arthritis. In severe cases, x-rays are more than sufficient. MRIs are most beneficial when x-rays show only mild degenerative changes where the pain patients are having is more than we would expect based on the severity of the x-rays.

Non-surgical treatment options

We always recommend starting with nonoperative treatment first. While it is not possible to regrow cartilage or to make the knee totally normal again, there are options to relieve pain. While treatment plans are individualized to specific patient situations, we typically start with some combination of injections, anti-inflammatory, physical therapy, and activity modification.

Knee injections

In general, there are two categories of injections we routinely use: steroid injections and hyaluronic acid injections. Both medications act to decrease inflammation in the knee to reduce pain and swelling. There are pros and cons to each type of injection, which you should discuss with your surgeon.

Is it possible to regrow cartilage? What about stem cells?

There are treatment options available such as PRP (platelet-rich plasma) or stem cell injections. These procedures are not covered by insurance for treatment of arthritis because there is no data or research that shows them to be beneficial. Hopefully we will be able to regrow cartilage in the future, but there is currently no technology that makes this possible inside of an arthritic joint. Because there is no scientific evidence to support the benefits of these injections, we do not currently offer them for the treatment of knee arthritis.

What are the surgical options for knee arthritis?

The most common surgical procedure for arthritis is knee replacement. This may include a total knee replacement or a partial knee replacement (discussed below). Sometimes people will refer to having an arthroscopic procedure performed to “clean out” the arthritis from the knee. This is generally a misnomer. Knee arthroscopy performed in patients with arthritis may be indicated in some situations, but this procedure can often result in little improvement and sometimes worsening of symptoms. This needs to be discussed with your surgeon on a case-by-case basis. Other procedures include osteotomies – or cutting and repositioning of the bone. These procedures are mostly historical. In today’s practice, osteotomies are generally reserved for very young patients who do not wish to undergo knee replacement, and have arthritis or cartilage damage limited to only one compartment of the knee.

What is a knee replacement?

During an operation, the surgeon removes the arthritic surfaces of the bone and resurfaces the ends of the bone with metal or ceramic caps. A plastic insert separates these caps so that in the place of bone on bone, you have a joint surface which doesn’t grind and is not painful. A total knee replacement replaces both the medial (inside) and lateral (outside) compartments of the knee. The joint between the kneecap and femur is typically replaced as well.

Total Knee Replacement

What is a partial knee replacement?

A partial knee replacement only replaces a single compartment of the knee. The most common type of partial is a medial unicompartmental replacement, wherein only the medial (inside) portion of the knee joint is replaced. It is also possible to replace just the patellofemoral (under the kneecap) or lateral (outside) joint. Metal or ceramic and plastic components are also used for partial replacements. With a partial knee replacement, patients keep all the native ligaments of the knee (ACL, PCL, MCL, and LCL), which may allow for more rapid improvement and a more “normal” feeling knee. However, not everyone is a candidate for partial replacement. This needs to be discussed on a case-by-case basis with your surgeon.


There are complications that can happen with any surgery such as bleeding, wound problems, infection, pain, damage to the structures around the knee, and medical problems such as heart attack or blood clots. Complications that we particularly pay attention to include: infection, stiffness, instability, persistent pain, and loosening of the components. We take special precautions around the time of surgery to avoid complications, but they do happen. You should discuss these potential complications with your surgery prior to proceeding with surgery.

How can I minimize my risk of complication?

Despite best efforts, complications can occur for any patient. However, there are certain factors that can be optimized in order to lower the risk of infection. The most common modifiable risk factors include smoking, diabetic control, and obesity. These factors play a significant role in the risk of complications such as wound problems and infection. Based on your situation, your surgeon may recommend modification of these variables prior to surgery.


Day of surgery: We typically have our patients up walking and putting full weight on the leg within a few hours following the surgery. We use a combination of pain control techniques that allows patients to mobilize soon after surgery with very manageable pain control. A physical therapist will teach you a few simple exercises to do, practice using a walker, and practice going up and down stairs. It is now common for patients to go home either the same day or one day following knee replacement.
First two weeks: For the first two weeks, you should plan to have help. You can get up to walk short distances, but will need to spend a fair amount of time relaxing, icing, elevating, and working on range of motion. Most patients will start physical therapy about 5-7 days after surgery. Patients typically use a walker for the first two weeks.
Weeks 2-6: After two weeks, patients start doing more and more at their own rate. The knee will still be sore, but patients are encouraged to gradually increase activities as tolerated. You continue to work with physical therapy during this period to maximize strength and range of motion.
Weeks 6-12: During this period, the knee continues to calm down and patients can start getting back to usual activities as tolerated. The knee can still be sore and there can be some swelling. Most patients can get back to work during this period, though it may be sooner or later based on an individual’s recovery and the exact work requirements.
Weeks 12+: Most patients will be back to doing all activities by three months. In general, there are no long-term restrictions. Our goal is to get patients back to recreational activities they enjoy including golfing, skiing, tennis, hiking, etc. That being said, a knee replacement is a mechanical device that can wear out with time, so it may be advisable to avoid repetitive impact activities such as distance running, jumping, and other high impact activities.


Replacement surgery is a very reliable option to treat arthritic knee pain with most patients able to get lasting relief from pain and improved ability to perform daily and recreational activities. Most knee implants will last 15-20 years, though there can be great variability. If there are early complications such as infection, the lifespan can be short, but many patients get more than 20 years out of a knee replacement.

Why should I have my knee replacement done at ROC?

At ROC, we have the most comprehensive team of expert surgeons in Northern Nevada. This allows us to provide our patients with expert care, from nonoperative treatments such as physical therapy and injections to precision joint replacements to revision of even the most complex revision cases. Our Joint Teams’ experience and dedicated focus allows them to combine cutting edge technology with tried and true principles to give patients the best chance at an excellent outcome.