Treatment of Knee Osteoarthritis

Introduction to Treatment

• The American College of Rheumatology recommends self-management programs including exercise and weight loss as first-line treatment for knee osteoarthritis 1
• The American College of Rheumatology recommends physical therapy as part of comprehensive management for knee osteoarthritis 1

Pharmacological Management

• The American College of Rheumatology strongly recommends topical NSAIDs as first-line treatment for knee osteoarthritis 1
• The American College of Rheumatology weakly recommends topical capsaicin as first-line treatment for knee osteoarthritis 1
• The American College of Rheumatology recommends acetaminophen and/or oral NSAIDs as first-line treatment for knee osteoarthritis, although evidence suggests limited efficacy for acetaminophen 1, 2, 3
• The American College of Rheumatology recommends duloxetine as alternative or adjunctive therapy for knee osteoarthritis, for patients with inadequate response to acetaminophen and NSAIDs 1, 2, 3

Intra-Articular Injections

• The American Academy of Orthopaedic Surgeons recommends against the routine use of hyaluronic acid injections for knee osteoarthritis, based on inconsistent evidence from 17 high-quality and 11 moderate-quality studies, which did not identify a subset of patients that might benefit from this treatment 4
• The American College of Rheumatology and American Academy of Orthopaedic Surgeons provide moderate strength recommendations against routine use of hyaluronic acid injections due to limited clinical benefit, although hyaluronic acid may possess structure modification properties, but more studies using standardized methodology are required, and the effect size is relatively small, suitable patients are not well defined, and pharmacoeconomic aspects are not well established 5
• The American College of Rheumatology recommends intra-articular corticosteroid injections for persistent pain in knee osteoarthritis, with a stronger evidence base than hyaluronic acid preparations, and may be considered for moderate to severe pain 1, 4, 2, 3, 6
• Hyaluronic acid injections may be considered in specific clinical scenarios, such as when patients have failed other interventions including non-pharmacologic therapies, topical and oral NSAIDs, and intraarticular corticosteroid injections, as part of shared decision-making when other alternatives have been exhausted 2, 3
• The recommended dosage for hyaluronic acid knee injections is typically administered as a course of 3-5 weekly injections, with common formulations ranging from 20-48 mg per injection, depending on the specific product used, as shown in the following table:

• Pain relief and functional improvement can last up to 6 months after completing the injection course, with effects generally slower in onset but longer-lasting than corticosteroid injections, and repeat courses may be considered after 6 months if beneficial 7, 5, 2, 3

Surgical Management

• For patients with refractory pain associated with disability and radiological deterioration, joint replacement should be considered rather than continuing with injectable therapies, according to the Annals of the Rheumatic Diseases 5
• The Mayo Clinic Proceedings guidelines suggest that intra-articular corticosteroid injections would be more appropriate as the next step in management rather than viscosupplementation, and if corticosteroid injections fail to provide adequate relief, surgical evaluation may be warranted 6, 1

Treatment Approach

• The American College of Rheumatology/Arthritis Foundation recommends a stepped approach to treatment, starting with core treatments such as weight loss, strengthening exercises, and aerobic fitness training, before considering other interventions like viscosupplementation or corticosteroid injections 3
• Viscosupplementation may be considered for longer-term pain relief (6-12 months) compared to corticosteroid injections, which provide better short-term relief, as suggested by the VA/DoD guidelines 1