Stages of Knee Osteoarthritis

Medically Reviewed by Carmelita Swiner, MD on March 02, 2023
3 min read

Osteoarthritis (OA) happens when the cartilage buffer in your joints goes away over time. The bone underlying the cartilage becomes denser and enlarges. This also impacts nearby tissue and leads to pain, swelling, a hard time moving, and stiffness. The condition doesn’t have a cure, but treatments can help control it.

Most people get this “wear-and-tear” disease in their knees, hips, hands, and spine, but it can happen in any joint.

Doctors use multiple methods to diagnose knee osteoarthritis. They may examine your legs, take X-rays, and ask you about your symptoms. Here’s how your doctor knows what stage you could have.

Stage 0

The joint cartilage between your bones is healthy and there are no signs of the disease. Treatment isn’t needed.

Stage 1

You may start to lose cartilage, but joint space probably isn’t getting smaller at this point. Growths on the end of your bones called bone spurs could start to form. It can hurt to bend and straighten your leg because of them, but you might not feel this for years.

Stage 2

Your knee begins to ache after a hard workout or a day when you’re very active. The space between your bones may get smaller as cartilage reduces. You have bone spurs.

Stage 3

Pain comes and goes as you move. You have less joint space from cartilage loss, and your bones are changing a lot. The ends of them could be thicker, denser, and deformed. You also have more bone spurs. Plus, fluid may build up and cause swelling.

Stage 4

This is the most extreme part of the disease. Daily movement hurts intensely. There is very little to no cartilage in your joint. Bone spurs are much bigger. The ends of your bones are harder and deformed.

Stages 1 to 3 are the early phases of osteoarthritis. Your doctor may recommend a mix of lifestyle changes, medication, and procedures during this time.

It’s important to lessen pressure on your knees, and you need to avoid activities that make pain worse. This means weight loss if you’re overweight (BMI of 25-29.9) or obese (BMI of 30 and over). It also helps if you work out regularly. If you’re highly active, swap high-impact exercise like running for low-impact movement like Pilates or walking.

Exercise in general will make it easier for you to move, make your knees more stable through stronger muscles, and lessen pain. Hot and cold remedies can help with day-to-day symptoms as well.

Your doctor may also recommend Kinesio taping and acupuncture. It’s not known how well these alternative medicine methods work, but they may be worth trying.

As the disease progresses and pain gets worse, nonsteroidal anti-inflammatory drugs (NSAIDs) you swallow or put on your skin provide relief and work with nondrug treatments. If those don’t help or aren’t options, other pain relief medications are available. These include:

Water-cooled radiofrequency ablation may work if other treatments don’t make symptoms better. The technique gets rid of nerves that tell your brain you’re in pain. Results last until the nerves grow back -- about 6 months to 2 years. You can have this process as many times as you need to for continued relief.

Osteoarthritis can affect the alignment of your knee when it damages one side more than the other. A cane or brace helps with this issue and provides support if you feel like you might fall when you put weight on the most affected knee. An osteotomy could also help. During this surgery, your doctor cuts and changes the shape of your femur or tibia to fix the alignment problem.

When other therapies fail, arthroplasty is the last option. In this surgery, your doctor removes damaged parts of your knee and puts a metal or plastic part in their place. If that doesn’t work, connecting the bones through fusion may ease pain. The downside is that after this procedure, other joints end up with more pressure on them to compensate for the loss of motion in the fused joint.