Early Diagnosis and Management of Knee OA
Knee osteoarthritis (OA) is the most common type of joint disease and leading cause of disability in elderly more than 70 years. It has a huge financial burden costing US$ 100 billion annually in USA.1 OA is an active disease process involving cartilage destruction, subchondral bone thickening, synovial inflammation and new bone formation. The functional changes occurring in an individual can be mild, moderate and severe.2
The main causes for knee OA are:2
Signs and Symptoms:
There are several signs and symptoms of OA, the most prominent of which are pain, stiffness, swelling and crepitus.3 Knee X-ray is generally used for the diagnosis. Kellgren–Lawrence grading system is a radiological classification of knee OA. It progresses from grade 0 to grade 4 and is based on x-rays.4 Knee Society function score is an objective scoring system to rate the knee and patient’s functional abilities such as walking and stair climbing.5
The process underlying OA cannot be reversed, but symptoms can usually be effectively managed with lifestyle changes, physical and other therapies, medications, and surgery. Lifestyle and home remedies include patient education, heat and cold, weight loss, exercise and physical therapy.6 American Academy of Orthopaedic Surgeons (AAOS) 2013 recommendation for symptomatic knee OA includes oral nonsteroidal anti-inflammatory drugs (NSAIDs), topical NSAIDs and tramadol for pain relief.7
Physiotherapy and self-exercises help in joint stiffness, effusion and synovitis, aid in swelling; whereas, physiotherapy and quadriceps strengthening exercises provide relief in crepitus.8
Other modalities of treatment include viscosupplement intra-articular injection such as Synvisc-One® which is cross-linked, has high molecular weight, and mimics healthy and young synovial fluid. The sites of injection are extension superolateral and flexion inferolateral.9-11
Total knee replacement (TKR) is an effective treatment for end-stage disease of the knee. TKR indications are frequent painkillers, reduced walking distance and night pain. The criteria for TKR include older patients with modest activity, younger patients with disabling systemic arthritis and post-traumatic arthritis.12
The leading cause of failure after TKR was polyethylene wear, followed by infection, arthrofibrosis, malalignment/malposition and component loosening. Although the infection rate was lower and the incidence of component loosening was higher in the younger patients when compared to patients >55 years of age, the differences did not demonstrate statistical significance.13
Early diagnosis is important to support and empower the patient to attend to lifestyle factors that influence the disease. In the early stages of the knee OA, X-rays are frequently normal. As the disease progresses, loss of joint space, subchondral sclerosis and osteophyte formation are seen. Regular follow-up helps to maintain management and adherence.14
1. Osteoarthritis Action Alliance. Osteoarthritis Is Widespread and Costly – Both to Individuals and to the Nation. Available at: https://oaaction.unc.edu/policy/cost-of-osteoarthritis. Accessed on 7 May 2019. 2. Chen D, et al. Osteoarthritis: Toward a comprehensive understanding of pathological mechanism. Bone Res. 2017;5:16044. 3. Heidari B. Knee osteoarthritis prevalence, risk factors, pathogenesis and features: Part I. Caspian J Int Med. 2011;2(2):205–212. 4. Felson DT, et al. Defining radiographic incidence and progression of knee osteoarthritis: Suggested modifications of the Kellgren and Lawrence scale. Ann Rheum Dis. 2011;70(11):1884–1886. 5. Scuderi GR, et al. The new knee society knee scoring system. Clin Orthop Relat Res. 2012;470(1):3–19. 6. Mayo Clinic. Osteoarthritis. Available at: https://www.mayoclinic.org/diseases-conditions/osteoarthritis/diagnosis-treatment/drc-20351930. Accessed on 7 May 2019. 7. AAOS. Treatment of Osteoarthritis of the Knee: Evidence-based Guideline 2nd Edition. 2013. Available at: https://www.aaos.org/research/guidelines/treatmentofosteoarthritisofthekneeguideline.pdf. Accessed on 7 May 2019. 8. Anwer S, et al. Effect of home exercise program in patients with knee osteoarthritis: A systematic review and meta-analysis. J Geriatr Phys Ther. 2016;39(1):38–48. 9. Stitik TP, et al. Synvisc® in knee osteoarthritis. Future Rheumatol. 2008;3(3):215–222. 10. SYNVISC/Synvisc-One European Prescribing Information. Naarden, The Netherlands; Genzyme Europe B.V.; 2013. 11. Balazs EA, et al. Hyaluronic acid in synovial fluid. I. Molecular parameters of hyaluronic acid in normal and arthritic human fluids. Arthritis Rheum. 1967;10(4):357–376. 12. Medical Advisory Secretariat. Total knee replacement: An evidence-based analysis. Ont Health Technol Assess Ser. 2005;5(9):1–51. 13. Kim KT, et al. Causes of failure after total knee arthroplasty in osteoarthritis patients 55 years of age or younger. Knee Surg Relat Res. 2014;26(1):13–19. 14. Favero M, et al. Early knee osteoarthritis. RMD Open. 2015;1(Suppl 1):e000062. doi:10.1136/rmdopen-2015-000062.
PRP helps in knee OA: Myths and facts
What is platelet-rich plasma (PRP)?
Osteoarthritis (OA) is a degenerative disease involving joint damage; an inadequate healing response and progressive deterioration of the joint architecture that commonly affects the knee and/or hip joints.1 Autologous blood-derived products possess much promise in the repair and regeneration of tissue and have important roles in inflammation, angiogenesis, cell migration and metabolism in pathological conditions, including OA.1
Even though blood is mainly a liquid (called plasma), it also contains small solid components (red cells, white cells and platelets). Platelets are best known for their importance in clotting blood. However, platelets also contain hundreds of proteins known as growth factors that are significant in the healing of injuries.2
PRP is plasma with many more platelets than in blood. The concentration of platelets and, thereby, the concentration of growth factors can be 5–10 times greater (or richer) than usual.2
Which are the conditions where PRP can be used for treatment?2
How is PRP prepared?
How does PRP work?
Although it is not exactly clear how PRP works, laboratory studies have shown that the increased concentration of growth factors in PRP can potentially speed up the healing process.2
This can be done in either of the two ways:2
Role of PRP in knee OA1
When can PRP be used in OA?
Is PRP effective in advanced stages of OA?
What is the difference between viscosupplementation and PRP?
Myths and facts6,7
If you are considering PRP or thinking it would work for you, make sure you separate the fact from myths before you move forward with the treatment.
PRP could be effective only in the early stages and when there is injury and some cartilage left for healing, and not in the advanced stages. Initial studies on the use of PRP in OA are positive, but further studies should be conducted prior to its recommended use.
1. O'Connell B, Wragg NM, Wilson SL. The use of PRP injections in the management of knee osteoarthritis. Cell and Tissue Research. 2019;376(2):143–52. 2. OrthoInfo. Platelet-Rich Plasma (PRP). Available at: https://orthoinfo.aaos.org/en/treatment/platelet-rich-plasma-prp/ . Accessed on 05 September 2019. 3. Cook CS and Smith PA. Clinical update: Why PRP should be your first choice for injection therapy in treating osteoarthritis of the knee. Current Reviews in Musculoskeletal Medicine. 2018;11(4):583–92. 4. Cianflocco AJ. Viscosupplementation in patients with osteoarthritis of the knee. Postgraduate Medicine. 2013;125(1):97–105. 5. Harmon KG and Rao AL. The use of platelet-rich plasma in the nonsurgical management of sports injuries: Hype or hope? ASH Education Program Book. 2013;2013(1):620–6. 6. Wang HL and Avila G. Platelet rich plasma: Myth or reality? European Journal of Dentistry. 2007;1(4):192. 7. Dhurat R, Sukesh MS. Principles and methods of preparation of platelet-rich plasma: A review and author’s perspective. Journal of Cutaneous and Aesthetic Surgery. 2014;7(4):189.