The presentation
Presenting experience with the Tetrous implant for rotator cuff repairs.
What a rotator cuff repair involves
The rotator cuff is the group of four tendons that hold the ball of the shoulder centred in its socket and help to lift and rotate the arm. A tear separates one or more of those tendons from the bone they attach to, which typically causes pain, weakness and difficulty raising the arm. A repair, usually carried out arthroscopically through small portals, brings the torn tendon back to its footprint on the bone and holds it there with anchors and sutures while it heals. Individual results vary.
What the implant is for
The difficulty in rotator cuff repair is not usually holding the tendon against the bone; it is getting it to heal there. A repaired tendon tends to heal with scar tissue rather than reforming the specialised transition zone, the enthesis, that originally joined tendon to bone.
That transition zone is a graded structure, running from tendon through fibrocartilage to bone, and it exists because the two tissues have very different stiffness. A junction of scar tissue does not distribute load the way the original enthesis did, which is one of the reasons a repair can come apart again.
The Tetrous implant addresses this by placing demineralised bone fibres at the tendon-bone interface, with the aim of encouraging a more natural enthesis to form. It is an approach to the biology of healing rather than to the mechanics of fixation.
The supporting evidence at this stage comes largely from preclinical work rather than human clinical outcome data, so this remains a developing approach. Individual results vary.
Related information
- This work was also presented at ISAKOS, covered in our post on a biological approach to rotator cuff repair
- Our rotator cuff repair page
- Our post on rotator cuff repairs and retear
- Our rotator cuff tear page