Knee Osteoarthritis: Symptoms & Treatment

If you've been told you have knee arthritis — or your knee has been telling you so on the stairs — the reassuring truth is that it's common, it's manageable, and you have real options at every stage. This guide covers how knee osteoarthritis feels, how it tends to progress, and the full continuum of care, from simple activity changes to replacement when the time is right.

What knee osteoarthritis is

Smooth cartilage normally caps the ends of the bones in your knee so they glide painlessly. In osteoarthritis, that cartilage gradually wears down. The knee has three compartments, and arthritis can affect just one — which sometimes opens the door to a partial replacement — or spread across the whole joint. As the cushion thins, the knee becomes stiff, swollen, and painful, and it can begin to change shape over time.

What knee arthritis feels like

Knee arthritis has a recognizable pattern. The most common signs include:

• Pain on stairs — especially going down, one of the earliest and most telling signs.
• Stiffness after sitting — the knee “gels” after a movie or a long drive, then loosens as you walk.
• Swelling — recurrent puffiness that flares with activity.
• Grinding or catching — a sense of roughness, clicking, or the knee briefly hanging up.
• The knee “giving way” — a loss of confidence that it will hold you, which makes uneven ground and stairs feel risky.
• A shrinking walking tolerance — distances that were easy start to feel limited.
• Night pain — aching that disturbs sleep as arthritis advances.
• A change in alignment — some knees gradually become more bow-legged (or, less often, knock-kneed) as cartilage wears unevenly.
• Stepping back from what you love — quietly giving up golf, tennis, hiking, travel, or the gym.

How it progresses — and realistic expectations

Osteoarthritis is generally progressive, but rarely in a straight line: many people have long, comfortable stretches interrupted by flares. How fast it advances varies widely, and — this matters — X-rays don't always match symptoms. Some people with significant arthritis on film feel relatively good, and others with milder changes hurt more.

Over time, uneven cartilage wear can subtly change the knee's alignment, which is part of why arthritis tends to be self-reinforcing. Because cartilage can't be regrown, the honest goal of nonsurgical care isn't to reverse the arthritis — it's to control symptoms and keep you active for as long as possible.

Nonsurgical treatment: what comes first

Almost everyone starts here, and many patients manage their arthritis this way for years. The options build on one another — our complete guide to nonsurgical treatment of hip & knee arthritis covers them in depth. Here's how they fit:

Activity modification

Favoring lower-impact activities — cycling, swimming, the elliptical, and walking over running and deep squatting — and managing weight where relevant meaningfully reduces load and pain. The goal is to keep moving, not to stop.

Physical therapy

Strengthening the quadriceps and the muscles around the knee improves stability, reduces pain, and restores confidence in a knee that's been feeling unreliable. It's a cornerstone of nonsurgical care.

Cortisone (corticosteroid) injections

A cortisone injection can quiet inflammation and a swollen, painful flare, giving meaningful — if temporary — relief. It's a useful tool for getting through a bad stretch or an important event, used selectively. See our guide to cortisone injections.

Hyaluronic acid (gel) injections

These aim to supplement the knee's natural lubrication. They're more established for the knee than other joints and are a reasonable option for some patients with mild-to-moderate arthritis — with realistic expectations, since they don't help everyone. See our guide to gel (hyaluronic acid) injections.

PRP and regenerative options

Platelet-rich plasma (PRP) is an area of genuine interest and ongoing research. The balanced view: PRP may help selected patients with mild-to-moderate symptoms, but it is not a cure for advanced arthritis and should be viewed as one part of a broader treatment strategy — not a replacement for proven options, and not the miracle it's sometimes marketed to be. For the full picture, see our evidence-based guide to PRP.

When knee replacement becomes reasonable

Replacement isn't about a number on an X-ray — it's about your life. It becomes a reasonable option when arthritis limits the things that matter to you (walking, sleeping, working, the activities you love) despite a good trial of nonsurgical care. Depending on how much of the knee is involved, that may mean a partial replacement (resurfacing one worn compartment) or a total replacement. Modern knee replacement is highly successful, with more than 75% of implants remaining intact at 30 years. For help recognizing that point, see signs you may need a knee replacement.

When that time comes, you can explore Dr. Harb's knee replacement options (partial and total), the recovery timeline, what to expect with swelling afterward, and how to prepare for surgery.

Realistic goals of treatment

Whatever stage you're at, the goals are the same: relieve your pain, keep you moving, and protect the active life you want — whether that's with activity changes and an occasional injection today, or a well-timed replacement down the road. Knee arthritis is a manageable condition, and with the right plan, most patients get back to doing what they love.