Knee Osteoarthritis Treatment Options: A Complete Guide

What is knee osteoarthritis?

Knee osteoarthritis (OA) occurs when the articular cartilage that cushions the ends of the bones gradually breaks down, leading to pain, stiffness, swelling, and reduced function. It is the most common form of arthritis. Age, prior knee injury, obesity, and genetics all contribute to its development.

Symptoms range from mild morning stiffness and activity-related aching to severe pain at rest and significant walking limitation. X-rays can show joint space narrowing, bone spurs (osteophytes), and changes in the bone beneath the cartilage — but the degree of imaging change does not always match the degree of symptoms.

Why is exercise the cornerstone of knee OA treatment?

It may seem counterintuitive to exercise a painful knee, but physical activity is consistently the most effective non-surgical treatment for knee osteoarthritis. Multiple national and international guidelines — including the AAOS, OARSI, and others — recommend exercise as a first-line intervention for all people with knee OA regardless of severity 1Ref 1Brophy RH, Fillingham YA (2022).AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition.Exercise, topical NSAIDs, injection recommendations, and corticosteroid injection guidance for knee OA2Ref 2Bannuru RR, Osani MC, Vaysbrot EE, et al. (2019).OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis.Exercise and weight management as cornerstone non-surgical treatment for knee OA3Ref 3Fransen M, McConnell S, Harmer AR, Van der Esch M, Simic M, Bennell KL (2015).Exercise for osteoarthritis of the knee.Land-based exercise produces clinically meaningful short-term reductions in pain and improvements in function for knee OA.

A Cochrane systematic review of land-based exercise for knee OA found it produces clinically meaningful short-term reductions in pain and improvements in physical function 3Ref 3Fransen M, McConnell S, Harmer AR, Van der Esch M, Simic M, Bennell KL (2015).Exercise for osteoarthritis of the knee.Land-based exercise produces clinically meaningful short-term reductions in pain and improvements in function for knee OA. Benefits come from: - Strengthening the muscles around the knee (especially quadriceps and hip abductors), which reduces joint load - Improving joint stability - Reducing systemic inflammation through regular physical activity - Maintaining a healthy body weight

Recommended exercise types include strength training, aquatic exercise, cycling, and walking programs. A physical therapist can design an individualized program and ensure you are not loading the joint in ways that worsen pain.

What is the role of weight management?

Weight loss is a strongly recommended intervention for people with knee OA who have excess body weight 1Ref 1Brophy RH, Fillingham YA (2022).AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition.Exercise, topical NSAIDs, injection recommendations, and corticosteroid injection guidance for knee OA2Ref 2Bannuru RR, Osani MC, Vaysbrot EE, et al. (2019).OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis.Exercise and weight management as cornerstone non-surgical treatment for knee OA. The mechanical forces through the knee joint are substantially higher than body weight alone, meaning even modest weight reduction can produce a meaningful decrease in joint load and pain.

Weight loss combined with exercise produces greater improvements in pain and function than either intervention alone.

What medications are used for knee OA?

Acetaminophen (paracetamol): Often used first for mild pain, but its effectiveness for knee OA pain is modest compared to NSAIDs according to more recent reviews.

Oral NSAIDs (ibuprofen, naproxen, diclofenac): More effective for pain and function than acetaminophen in most patients. Risks include gastrointestinal irritation, kidney effects, and (at higher doses or with prolonged use) cardiovascular concerns. Used at the lowest effective dose for the shortest necessary time 4Ref 4MedlinePlus / U.S. National Library of Medicine (2024).Ibuprofen: MedlinePlus Drug Information.Oral NSAID safety considerations for pain management.

Topical NSAIDs (topical diclofenac): The AAOS guideline recommends topical NSAIDs for knee OA. They provide meaningful pain relief with substantially less systemic absorption than oral forms — an advantage for those with GI or cardiovascular concerns 1Ref 1Brophy RH, Fillingham YA (2022).AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition.Exercise, topical NSAIDs, injection recommendations, and corticosteroid injection guidance for knee OA.

Duloxetine: A serotonin-norepinephrine reuptake inhibitor with evidence for chronic pain conditions including knee OA pain. An option when other medications are insufficient or not tolerated.

Supplements (glucosamine, chondroitin): Evidence for these supplements is mixed; most major guidelines do not recommend them specifically for knee OA. Discuss their use with your clinician.

What injections are available for knee OA?

Intra-articular corticosteroids: Injections of corticosteroids directly into the knee joint typically provide several weeks to a few months of meaningful pain relief. They are useful for acute flares and as a bridge while pursuing rehabilitation. Repeated injections at frequent intervals may have cartilage effects — your clinician will advise on appropriate frequency 1Ref 1Brophy RH, Fillingham YA (2022).AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition.Exercise, topical NSAIDs, injection recommendations, and corticosteroid injection guidance for knee OA.

Hyaluronic acid (viscosupplementation): These injections replace or supplement the joint's natural lubricant. Evidence for benefit is mixed, and the AAOS guideline has cautious recommendations. Some patients report meaningful relief. Discussion with your orthopedic surgeon can help weigh whether this is appropriate for you.

Platelet-rich plasma (PRP): PRP injections have generated interest but the evidence remains inconsistent. Guidelines do not yet strongly recommend them for knee OA.

What surgical options exist for knee osteoarthritis?

Arthroscopic surgery for knee OA (cleaning out loose debris, trimming frayed tissue) is generally not recommended for patients whose primary problem is diffuse osteoarthritis 5Ref 5Sihvonen R, Paavola M, Malmivaara A, Itälä A, Joukainen A, Nurmi H, Kalske J, Järvinen TLN; FIDELITY Group (2013).Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear.Arthroscopic surgery not superior to sham for degenerative knee conditions6Ref 6Thorlund JB, Juhl CB, Roos EM, Lohmander LS (2015).Arthroscopic surgery for degenerative knee: systematic review and meta-analysis of benefits and harms.Arthroscopic surgery provides no meaningful benefit over non-surgical treatment for degenerative knee OA. Studies comparing arthroscopic procedures with sham surgery showed no meaningful difference in outcomes for most patients with degenerative knee OA.

High tibial osteotomy (HTO): Realigning the leg to shift load away from the more damaged compartment of the knee. Appropriate for younger patients with isolated medial or lateral compartment OA and malalignment.

Total knee arthroplasty (TKA) or partial knee replacement: The most definitive surgical treatment. Recommended when pain is severe, functional limitations are significant, and non-surgical treatments have been adequately tried and found insufficient. See the dedicated article on joint replacement timing for more detail.

An orthopedic surgeon is the right specialist to discuss surgical options. Gale can help you find one and prepare your questions.