Although OA is a process of articular cartilage “wear and tear”, its changes are biochemically mediated , through an imbalance between intra-articular anabolic and catabolic cytokines . This results in cartilage loss, synovial inflammation and eventually leads to mechanical and biological dysfunction of the joint .

The articular cartilage due to its avascular nature and the limited self-renewal capacity of chondrocytes has remarkably poorer regenerative ability than other tissues .

Rationale :Current treatments for early phase of degenerative arthritis focus on relieving inflammation and pain , but have no effect on the natural progression of the disease because it does not improve the biochemical environment (homeostasis) of the joint.

Conservative treatments including medications such as non-steroidal anti-inflammatory drugs (NSAIDs) and steroids as well as supplements including glucosamine, chondroitin sulphate, omega-3 fatty acids , cannot alter the natural history of the disease.Steroids focus on relieving inflammation and pain

Costly total knee arthroplasty (TKA) then follows when other treatment options have been exhausted , however patients experience a higher risk of death from mental and inflammatory musculoskeletal diseases, with a serious adverse event rate of 5.6% and a 0.2% mortality rate .

Novelty:Recently, extraction of the mesenchymal stem cells (MSCs) obtained from autologous bone marrow (BMA) followed by concentration was introduced represents the next generation of injectable intra-articular orthobiologic therapy for patients with cartilage disease . 

MSCs are multipotent cells that exhibit strong self-renewal abilities, combined with a differentiation capacity to form chondrocytes, adipocytes, and osteocytes . These cells also have very important local paracrine affects to alter their local microenvironment to conditions favourable for regeneration and repair .

BMAC represents the safest and most feasible source of MSCs. Intra-articular application has resulted in pain reduction, functional improvement and/or tissue regeneration . BMAC is obtained through density gradient centrifugation of bone marrow aspirate (BMA) typically aspirated from the iliac crest . BMAC has been shown to provide elevated levels of hematopoietic stem cells (HSCs), MSCs, platelets, chemokines and cytokines including PDGF and TGF-β .These growth factors (GFs) are not only contained within the alpha granules of platelets, but they are also secreted by MSCs and can induce chondrogenesis of MSCs . GFs also initiate stem cell migration to the injury site and provide adhesion sites for the migrating stem cells . Moreover BMAC possesses in general, anti-inflammatory, angiogenic trophic and immunomodulatory properties that can potentially have anabolic and anti-inflammatory effects enhancing cartilage repair .There are only very few studies comparing steroids with BMAC.

To date, there have been several studies that have looked at BMAC for the treatment of osteoarthritis, with conflicting results secondary to the differences and/or inconsistencies in methodologies used throughout the studies . Therefore, the role of BMAC in osteoarthritis is not yet been established