Background: Knee osteoarthritis is the most common musculoskeletal progressive disorder that affects nearly 303 million people worldwide. This condition prevails in 10% males and 13% females among the elders above 60. Although there is conventional nonsurgical and surgical treatment available for knee osteoarthritis, there is a fascinating interest in bone marrow aspirate concentrate (BMAC) as well as adipose-derived mesenchymal stem cells (AD-MSC), including enzymatically treated stromal vascular fraction (SVF) and mechanically treated (microfat/nanofat) injections among physicians. Hence, this systematic review aims to determine the efficacy of BMAC and AD-MSCs (enzyme and mechanically treated) injections for knee osteoarthritis treatment. Methods: A systematic review was performed on the following data sources (PubMed, Scopus, Google Scholar, EMBASE, and Cochrane Library) published on March 31, 2021. The keywords or MeSH terms include 'Knee Osteoarthritis with 'Bone marrow aspirate concentrate' OR 'BMAC' or with 'Adipose-derived mesenchymal stem cells (AD-MSC)' or with 'Stromal vascular fraction' OR 'SVF' or 'Mechanically treated AD-MSC (mfat/nanofat)'. In addition, the retrieved articles were further reviewed to identify relevant research studies. Results: The authors reviewed and tabulated data based on the year of study, study type, therapy protocol, patient population, outcome measures, and interpretation. Among the 382 records screened, 43 studies (16 on BMAC and 27 on AD-MSCs) were included in the systematic review study. Among them, only 5 were randomized controlled trials. These selected studies demonstrated short-term positive outcomes such as improvement in knee pain and function with no adverse side effects. Moreover, researchers reported varied administration methods of BMAC or AD-MSC either as standalone or in combination with other conservative procedures such as PRP (Platelets Rich Plasma), HA (Hyaluronic acid), or surgery. Conclusions: BMAC and AD-MSC (enzymatically and mechanically treated) injections prove safer and more efficacious in patients with knee osteoarthritis for a shorter duration of 2 years. However, the available literature lacks high-quality studies with no varied clinical settings and long-term follow-up of more than two years.
The effectiveness of allogeneic mesenchymal stem cells therapy for knee osteoarthritis in pigs