The talk
Ken Cutbush spoke at the Royal North Shore Shoulder Symposium in Sydney about the Enfix prosthesis, an implant made from demineralised bone fibre (DBF), and its use in rotator cuff repair.
About the symposium
The Royal North Shore Shoulder Symposium is a long-standing Australian shoulder course directed at teaching shoulder surgery to orthopaedic surgeons. Courses of this kind combine lectures, panel discussion of cases where surgeons disagree, and practical sessions. Sessions on new implants and materials sit alongside the established teaching, which is where a talk such as this one belongs: the point is to set out the idea and the evidence behind it so that the surgeons in the room can judge it for themselves.
Why healing is the problem
Rotator cuff repairs typically heal with scar tissue. A healthy tendon, by contrast, attaches to bone through a specialised transition zone called an enthesis, which is structurally quite different from scar and better suited to transmitting load.
The proposition is that DBF implants placed in the repair footprint may induce the formation of an enthesis rather than scar. If that occurred, the expectation would be a repair that is less prone to retear and more durable over time.
What demineralised bone fibre is
Demineralised bone fibre is human donor bone that has been processed to remove its mineral content, leaving the collagen framework and the proteins held within it. Without the mineral, what remains is a pliable fibrous material rather than a hard graft, and it can be placed at the interface between tendon and bone at the time of a repair. The intention is that it acts as a scaffold which the body's own cells populate as healing proceeds, rather than as a permanent implant. Individual results vary.
The state of the evidence
It is important to be clear about what this rests on. The supporting work cited is from animal model studies. No human clinical outcome data was presented, and no healing or retear rates for this approach are available. The claims above are therefore the expected benefit on the basis of preclinical work, not a demonstrated result. Individual results vary.