A therapy that is still experimental, promising yes, but still under study. This is currently the opinion of the experts of the Italian Society of Orthopedics and Traumatology (Siot) regarding infiltrations with mesenchymal stem cells, one of the strategies that fall under the umbrella of orthobiology, the set of non-invasive treatments that exploit the regenerative power of the body’s cells in the orthopedic field, against disorders such as tendinitis and mild arthrosis.
Why use mesenchymal stem cells in orthopaedics
Mesenchymal stem cells are a particular type of stem cells that can be extracted from bone marrow or subcutaneous fat, he explains Pietro Simone Randelli of the University of Milan, First Orthopedic Clinic – ASST Gaetano Pini-CTO – PO Gaetano Pini of Milan (among the centers of excellence for knee, hip and shoulder orthopaedics) and vice-president Siot.
Hospitals of excellence: Noemi Penna’s guide 29 February 2024
They are the subject of interest for their regenerative capacity, because they can differentiate into different cell types, such as fibroblasts, osteoblasts, chondrocytes or muscle cells. But their possible uses in orthopedics rather concern their indirect action capabilities: that is, it is not the mesenchymal cells themselves that support tissue regeneration but rather the substances they produce. “We talk about the paracrine effect: these cells release substances that are able to instruct the surrounding cells of the target tissue – explains Randelli – in this way they can carry out a regenerative action, activating the resident cells, encouraging them to replicate. If we use them against cartilage lesions, for example, this will mean that the mesenchymal cells activate the chondrocytes and the resident stem cells of the cartilage.”
How to give a mesenchymal stem injection
The procedure involves the collection of a small number of stem cells (usually from subcutaneous fat) from the same patient: “We are talking about around 10-15 thousand cells for each treatment, which are then processed and injected into the sites of interest – Randelli continues – Until now the Their effectiveness has been demonstrated above all in the treatment of tendon disorders, such as those affecting the rotator cuff of the shoulder. However, there are other, more experimental fields in which they are used: this is the case in the initial cases of arthrosis of the knee, hip and shoulder. But it is good to remember that for these cases there are no incontrovertible efficacy data in the literature: we only know that on some patients they seem to work better. But we are much further behind than orthobiology treatments carried out with hyaluronic acid or platelet-rich plasma.”
Orthobiology against arthrosis, how and when hyaluronic acid is used by Anna Lisa Bonfranceschi 29 March 2024
Even where the evidence is stronger – as in the case of treating rotator cuff tendon injuries, as established by Randelli himself and colleagues – does not mean that they are always practicable. For several reasons: “First of all, in order to use the mesenchymal cells taken from the abdomen we need to perform an additional operation on the patient, and it is not certain that everyone is in a position to face anesthesia and post-op – explains the expert – Secondly, it is not used in all rotator cuff injuries, but more often in so-called revision surgeries. In fact, the tissues of the rotator cuff tend to break again after the operation, they can give way, and when reoperation is carried out, one of the supporting strategies is the use of mesenchymal stem cells, to stimulate the regenerative process.”
Hip and knee prostheses, a model to increase the success of operations by Anna Lisa Bonfranceschi 14 March 2024
When to use them against arthrosis
In osteoarthritis, the use of this procedure is usually reserved for mild cases in young patients, to delay any surgical interventions. “Stem cells are a promising non-surgical strategy against arthrosis, still awaiting evidence – concludes Randelli – In any case these procedures must be considered in the context of treatments that place patient education first. Changing your lifestyle, with weight reduction and sport, can in fact bring more benefits than joint injections, as we reiterate in the guidelines for knee osteoarthritis published a few months ago on Journal of Orthopaedics and Traumatology”.