Regenerative therapy for tendon and ligament disorders in horses: results of treatment with stemcells, blood products, scaffolds and growth factors review of the literature and meta analysis

摘要

Conventional treatments for tendon and ligament disorders give rise to functionally inferior repair tissue within a relatively long healing phase which results in a relatively high recurrence rate. There is however increasing evidence that intralesional treatments with cells, blood products, scaffolds and biological factors such as growth factors have a regenerative effect. In the present review the principal scientific findings on the clinical effects in living horses of, for example, bone-marrow-derived and adipose-tissue-derived mesenchymal stromal cells (MSCs), embryonic stem cells (ESCs) and blood products such as PRP (platelet rich plasma), ACP (auto)ogous conditioned plasma) and ACS (autologous conditioned serum) are summarized and discussed. Relating to horses, several scientific investigations with different study designs can be found in the literature: 1) Clinical case series, which allow a limited comparison of different treatment methods on the basis of the resulting recurrence rate. 2) Experimental animal studies on controlled artificial tendon defects, which often provide detailed results on the histological, biochemical and biomechanical quality of repair tissue. 3) Single placebo-controlled studies of naturally occurring tendinopathies which should, at least theoretically, provide the highest degree of evidence, however show methodological weaknesses in many cases. Among other aspects, the advantages and disadvantages of the various substrates, their biological safety, their effect with regard to the structural and biornechanical properties of different tendons and ligaments and their effect on the recurrence rote of tendon and ligament disorders are described and discussed. There is increasing evidence that substrates with regenerative potential are superior to other, i.e. conventional, treatments although it is still not clear which product or combination of substrates is most appropriate in individual cases.