Rotator cuff pathology: state of the art

The rotator cuff tendon undergoes degeneration and tear quite commonly in the elderly population and was rarely observed in patients under 50 years of age. In addition to ageing, smoking, diabetes mellitus and other comorbidities are known to be the risk factors of tendon tear. Bony anatomy of the acromion relative to the glenoid plays a role on the onset of degenerative cuff tears. The biological responses of chronic tendinopathy, degenerative tear and the following muscle atrophy and fatty infiltration are regulated by macrophages. Age, tear size and chronicity have direct influence on healing after rotator cuff repair. Systematic reviews have shown that there is better healing in larger tears with a double row repair compared with a single row repair, but no differences in clinical outcome. The tendon healing is characterised by a fibrovascular scar response rather than by regenerating normal tendon tissue. As a result, the material and structural properties are much weaker than the normal tendon-to-bone interface. With this knowledge, better repair techniques and repair methods are expected to be developed for better healing of the tendon.