Osteoarthritis and Chronic Knee Pain

Osteoarthritis is commonly known as general wear and tear of the joints. Other terms used are degenerative joint disease or degenerative arthritis. Osteoarthritis is chronic low-grade inflammation in the joint space leading to break down of cartilage, synovitis, subchondral bone remodeling, degeneration of ligaments and menisci, which result in pain, stiffness and decreased range of motion.

The root cause of osteoarthritis is often ligamentous instability from a trauma/injury or overuse. Instability of a joint results in chronic inflammatory responses leading to degeneration of cartilage and joint space narrowing.  If healing does not occur as the injury or instability continue our bodies will continue compensating by increasing calcium deposits leading to bone spurs, further inflammatory responses, and degeneration.

Platelet-rich plasma (PRP) therapy involves using your own blood plasma and platelets as an enriched source of growth factors and collagen-building precursors to reduce inflammation and stimulate healing of bone and soft tissue. PRP has been shown in studies to be more effective than hyaluronic acid and corticosteroids in reducing pain and improving function.

Other current treatments for osteoarthritis are bracing, weight loss, NSAIDs, corticosteroids and surgery.  Unfortunately, these options all have vast limitations and/or severe side effects.  A knee replacement on average lasts 15 years, which is why they are prolonged for as long as possible resulting in people resorting to chronic NSAID and corticosteroid use for pain management.  Many papers show corticosteroids lead to soft tissue damage, cell death and tendon atrophy, reduced bone mineral density, inhibit collagen synthesis, lead to insulin resistance, atrophy of muscles/skin, and depression. Chronic NSAID use has been shown to lead to increased risk of stomach ulcers and can be toxic to the kidneys and liver.

The University of California published mechanisms for how PRP modulates the repair and regeneration of joint tissue in osteoarthritis in the journal Tissue engineering. Part B, Platelet-Rich Plasma Modulates Actions on Articular Cartilage Lubrication and Regeneration.

The researchers wrote: 

PRP modulates the repair and regeneration of damaged articular cartilage in the joints and delays the degeneration of cartilage by stimulation of mesenchymal stem cell migration, proliferation, and differentiation into articular chondrocytes (the cells of cartilage).

They also determined the reduction of pain is a result of decreased inflammation of the synovial membrane where pain receptors are located.(1)

In a systematic review published in the journal of Arthroscopy: The Journal of Arthroscopic & Related Surgery, Efficacy of Intra-articular Platelet-Rich Plasma Injections in Knee Osteoarthritis: A Systematic Review. Six studies comparing the efficacy of hyaluronic acid and PRP treatments for symptomatic osteoarthritis were reviewed (739 patients, 817 knees, 39% males with a mean age of 59.9 years) Comparing patients with symptomatic knee OA, PRP injections resulted in significant clinical improvements up to 12 months’ post-injection. Clinical outcomes and The Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores are significantly better after PRP versus hyaluronic acid at 3 to 12 months’ post-injection. (2)

In study published in Sports Med Phys Fitness, Effect of single injection of platelet-rich plasma in comparison with corticosteroid on knee osteoarthritis: a double-blind randomized clinical trial compared PRP injections to cortisone steroid injections in the treatment of osteoarthritis. In the study 41 participants (48 knees), 66.7% women, average age of 61 years old were randomly divided and given either a PRP or cortisone injection. Results showed that the PRP group compared to the group treated with corticosteroid injection had improved pain relief based on the VAS (visual analog scale), improved activities of daily living and quality of life at 2 and 6 month follow ups. PRP also was more helpful in improving the 20 meter walk test than corticosteroid treatment, however none of the treatments had any impact on active or passive range of motion. (3)

Reference:

  1. Sakata R, Reddi AH. Platelet-Rich Plasma Modulates Actions on Articular Cartilage Lubrication and Regeneration. Tissue Eng Part B Rev. 2016 Apr 25
  2. Meheux CJ, McCulloch PC, Lintner DM, Varner KE, Harris JD. Efficacy of Intra-articular Platelet-Rich Plasma Injections in Knee Osteoarthritis: A Systematic Review. Arthroscopy. 2015 Sep 29. pii: S0749-8063(15)00659-3. doi: 10.1016/j.arthro.2015.08.005
  3. Forogh B, Mianehsaz E, Shoaee S, Ahadi T, Raissi GR, Sajadi S. Effect of single injection of Platelet-Rich Plasma in comparison with corticosteroid on knee osteoarthritis: a double-blind randomized clinical trial. J Sports Med Phys Fitness. 2015 Jul 14.
  4. Ayhan, E. (2014). Intraarticular injections (corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis. World Journal of Orthopedics,5(3), 351. doi:10.5312/wjo.v5.i3.351

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