A debilitating condition, knee osteoarthritis (OA) significantly impacts patients' lives, necessitating a multifaceted approach to management. Knee OA is a prevalent chronic joint condition characterised by the degradation of articular cartilage, accompanied by changes in the underlying bone and soft tissue.¹ With up to 25% of people over the age of 50 years suffering from knee OA,² it’s important for pharmacists to have a good understanding of the condition to effectively manage medications and provide informed guidance.

ETIOLOGY AND PATHOPHYSIOLOGY

The exact cause of knee OA is multifactorial, involving a complex interplay of genetic predisposition, biomechanical factors, joint injury, and systemic factors such as obesity and metabolic syndrome.3 Primary OA typically develops due to age-related wear and tear on the joint cartilage, while secondary OA may result from previous knee injuries, abnormal joint alignment, or inflammatory conditions such as rheumatoid arthritis.¹

UNIQUE CONSIDERATIONS:

Knee OA poses unique challenges due to its impact on mobility and quality of life. Be mindful of the following considerations when managing patients with knee OA:

• Functional impairment: Knee OA can significantly impair physical function and reduce patients' ability to perform daily activities.⁴
• Psychological impact: Chronic pain and disability associated with knee OA may lead to depression, anxiety, and decreased overall well-being.^5,6
• Comorbidities: Patients with knee OA often have comorbid conditions such as cardiovascular disease, diabetes, and hypertension, requiring comprehensive management.⁷

TREATMENT OPTIONS

Management of knee OA aims to alleviate pain, improve joint function, and enhance quality of life.

• Non-pharmacological interventions: Weight management, exercise (e.g., strengthening and low-impact activities), physical therapy, and heat/cold therapy are crucial for managing pain and improving function.⁸
• Pharmacological management:
  • OTC pain relievers: NSAIDs (nonsteroidal anti-inflammatory drugs) are recommended as first-line therapy for pain relief and inflammation.⁹
  • Topical agents: Topical NSAIDs,10 capsaicin cream,11 and menthol-containing12 creams can provide localised pain relief with fewer systemic side effects compared to oral medications.¹⁰
  • Intra-articular injections: Corticosteroid injections and hyaluronic acid injections are administered directly into the knee joint to reduce inflammation and improve joint lubrication, respectively.^14,15
  • Nutraceuticals: Glucosamine and chondroitin sulphate are popular OTC supplements believed to support joint health and alleviate osteoarthritis symptoms, although evidence supporting their efficacy is mixed.16 Boswellia and its extract may relieve pain and stiffness and improve the joint’s function.^17,18

While conventional pharmacological options remain valuable, emerging therapies such as those including Boswellia serrata extracts offer a promising adjunctive treatment modality with the potential to alleviate symptoms, improve joint function, and enhance overall quality of life for individuals living with knee osteoarthritis.

REFERENCES

1. Hsu H, Siwiec RM. Knee Osteoarthritis. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507884/

2. Goff AJ, Elkins MR. Knee osteoarthritis. Journal of Physiotherapy. 2021;67(4): 240-241. Available from: https://www.sciencedirect.com/science/article/pii/S1836955321000898

3. Coaccioli S, Sarzi-Puttini P, Zis P, Rinonapoli G, Varrassi G. Osteoarthritis: New Insight on Its Pathophysiology. J Clin Med. 2022 Oct 12;11(20):6013. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9604603/

4. Clynes MA, Jameson KA, Edwards MH, Cooper C, Dennison EM. Impact of osteoarthritis on activities of daily living: does joint site matter? Aging Clin Exp Res. 2019 Aug;31(8):1049-1056. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6661019/

5. Zheng S, Tu L, Cicuttini F, Zhu Z, Han W, Antony B, Wluka AE, Winzenberg T, Aitken D, Blizzard L, Jones G, Ding C. Depression in patients with knee osteoarthritis: risk factors and associations with joint symptoms. BMC Musculoskelet Disord. 2021 Jan 7;22(1):40. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7791830/

6. Sharma A, Kudesia P, Shi Q, Gandhi R. Anxiety and depression in patients with osteoarthritis: impact and management challenges. Open Access Rheumatol. 2016 Oct 31;8:103-113. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5098683/

7. Muckelt PE, Roos EM, Stokes M, McDonough S, Grønne DT, Ewings S, Skou ST. Comorbidities and their link with individual health status: A cross-sectional analysis of 23,892 people with knee and hip osteoarthritis from primary care. J Comorb. 2020 May 14;10:2235042X20920456. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7238776/

8. Dantas LO, Salvini TF, McAlindon TE. Knee osteoarthritis: key treatments and implications for physical therapy. Braz J Phys Ther. 2021 Mar-Apr;25(2):135-146. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7990728/

9. Magni A, Agostoni P, Bonezzi C, Massazza G, Menè P, Savarino V, Fornasari D. Management of Osteoarthritis: Expert Opinion on NSAIDs. Pain Ther. 2021 Dec;10(2):783-808. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8586433/

10. Shi C, Ye Z, et al. Multidisciplinary Guidelines for the Rational Use of Topical Non-Steroidal Anti-Inflammatory Drugs for Musculoskeletal Pain (2022). J Clin Med. 2023 Feb 15;12(4):1544. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9966446/

11. Can Capsaicin Cream Help Joint Pain? Hospital for Special Surgery. 2021. Available from: https://www.hss.edu/article_capsaicin_cream.asp

12. Kraemer WJ, Ratamess NA, et al. A cetylated fatty acid topical cream with menthol reduces pain and improves functional performance in individuals with arthritis. J Strength Cond Res. 2005 May;19(2):475-80. Available from: https://pubmed.ncbi.nlm.nih.gov/15903393/

13. Ayhan E, Kesmezacar H, Akgun I. Intraarticular injections (corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis. World J Orthop. 2014 Jul 18;5(3):351-61. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4095029/

14. hyaluronan injections. Versus Arthritis. 2024. Available from: https://versusarthritis.org/about-arthritis/treatments/drugs/hyaluronan-injections/

15. Cortisone Shots (Steroid Injections). Cleveland Clinic. 2024. Available from: https://my.clevelandclinic.org/health/treatments/cortisone-shots-steroid-injections

16. Popular Supplements for Arthritis: What You Need to Know. Arthritis Foundation. Available from: https://www.arthritis.org/health-wellness/treatment/complementary-therapies/supplements-and-vitamins/vitamins-supplements-arthritis

17. Yu G, Xiang W, Zhang T, Zeng L, Yang K, Li J. Effectiveness of Boswellia and Boswellia extract for osteoarthritis patients: a systematic review and meta-analysis. BMC Complement Med Ther. 2020 Jul 17;20(1):225. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7368679/

18. Andrea H. Zengion, Eric Yarnell. Herbal and Nutritional Supplements for Painful Conditions. Pain Procedures in Clinical Practice (Third Edition). Hanley & Belfus. 2011(20):187-204. Available from: https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/boswellia#:~:text=Herbs%20such%20as%20boswellia%20(an,and%20stiffness%20caused%20by%20osteoarthritis.