Current Situation of Adipose-Derived Stem Cells Treatments for Knee Ostheoarthritis and Hypothesis for a New Protocol Based on Cryoconservation and Multiple Injections of Mechanically Fragmented Adipose Tissue Extracts

Abstract

Osteoarthritis (OA) is a widespread degenerative joint disease. The knee arthroplasty has represented for about 40 years the main treatment option, when pain and functional decrease became unbearable for the patient. The knee arthroplasty represents a challenging surgical operation, in which, based on current data available, about 20% of the patients are left totally or partially unsatisfied with the clinical result. A recent therapeutic alternative for mild-to-moderate grade OA (Kellgren-Lawrence grade II to III) in order to delay (or ultimately avoid) the need for prosthetic surgery, is a treatment with Adipose-Derived Stem Cells (or ADSCs). The safety and efficacy in terms of functional improvement, cartilage repair and inflammation reduction were already reported for OA treatment through a single intra-articular injection of Micro-Fragmented Autologous Fat Tissue (M-FAT), which is known to be rich in ADSCs. This efficacy period appears to be ranging from several months to a few years. Research has shown that the effect of single-dose M-FAT treatment, despite being evident in most cases, is not statistically uniform among the studies now available. This is also due to different treatment protocols, that leave to every research group the ultimate choice of preparation methods, rules and exclusion criteria. It is possible, because of this, to hypothesize a new kind of treatment protocol based on a single surgical harvesting operation. The extract would then need to be cryopreserved and administered multiple times over a several-years period. We hope, thanks to the subsequent injections of purified extract, to prolong and boost the effect of the treatment. We tried to elaborate, based on our experience in the field, a new protocol for this multi-injection treatment. This protocol is going to be applied to a small number of patients and evaluated over time, to elaborate the actual benefit from a treatment like this.