Healing of the rotator cuff needs to occur between the tendon and bone for a repair of a rotator cuff tear to be successful. Immediately following the surgical procedure after the tendon is put back in contact with the bone a small layer of clot forms between the tendon and bone. In the first couple of weeks following the surgery specialised cells migrate from the blood stream into the clot, these cells are called fibroblasts. The role of the fibroblasts is to lay down collagen tissue (collagen is the matrix that is the predominant component of tendons and ligaments in the body). These collagen fibres are initially laid down in a haphazard manner. This lay down of collagen fibres occurs significantly in the first 4-6 weeks following the surgical procedure.
The collagen fibres need to be remodelled from a haphazard collection of fibres into a structure where the fibres run parallel to each other. As this occurs and fibres of the collagen matrix start to be realigned in parallel bundles strength returns to the connection between the tendon and the bone. This remodelling process occurs over a long period of time. However, it is most rapid in the first 4-12 weeks following the initial surgical procedure.
Remodelling occurs for at least 6-12 months following the procedure, but again gradually slows down and the majority is completed by 4-6 months. Strength continues to improve in the connection between the tendon and the bone for at least the first 12 months post operatively as the remodelling process fine tunes itself. The remodelling process is improved with light loading across the shoulder and light physiotherapy exercises provide this stimulus to this process.