Biologics and stem cell-based therapies for rotator cuff repair

Abstract

The rotator cuff is composed of several distinct muscles and tendons that function in concert to coordinate shoulder motion. Injuries to these tendons frequently result in permanent dysfunction and persistent pain. Despite considerable advances in operation techniques, surgical repair alone still does not fully restore rotator cuff function. This review focuses on recent research in the use of biologics and stem cell-based therapies to augment repair, highlighting promising avenues for future work and remaining challenges. While a number of animal models are used for rotator cuff studies, the anatomy of the rotator cuff varies dramatically between species. Since the rodent rotator cuff shares the most anatomical features with the human, this review will focus primarily on rodent models to enable consistent interpretation of outcome measures.

Keywords: injury; rotator cuff; stem cells; tendon.

Figure 1

Anatomy and cell morphology of the supraspinatus tendon enthesis. (Left) Schematic of the tendon-to-bone (T/B) insertion via fibrocartilage enthesis gradient. (Right) Toludine blue staining of the supraspinatus tendon inserting into the humeral head, beneath the acromion (plastic section, 20X). T: supraspinatus tendon, B: humeral bone; E: enthesis; A: acromion.

Figure 2

Overview schematic highlighting biologic and stem cell strategies for rotator cuff repair. (A) Cell-free biomimetic scaffolds can be implanted to control release of biomolecules or exert their own beneficial proliferative or differentiating effects on local tissues. (B) Stem/progenitor cells delivered to the injury site can modulate the local environment or undergo direct cell differentiation. (C) The combination of biomaterial scaffold and stem/progenitor cells has been explored in recent studies to increase healing after rotator cuff injury and repair.