Rotator Cuff Healing and the Bone Marrow ‘‘Crimson Duvet’’ From Clinical Observations to Science

The goal of improving rotator cuff healing has been a high priority for orthopedic shoulder surgeons since Codman showed the feasibility of repair in 1909. Early efforts were directed toward improving surgical techniques to optimize the mechanical tendon fixation to bone. These efforts have been very successful and include improved sutures and bone anchors, less complicated suture passing and knot tying, better methods to relieve impingement and release tethered tendons, and advances in postoperative protection and rehabilitation. Despite these important advances, there continues to be a large percentage of cuff repairs that fail, leaving the patients with a less-than-optimal function. Recent researchers have reported re-rupture rates after open or arthroscopic rotator cuff repairs of between 13% and 94%. Over the last 20+ years, our shoulder team at Southern California Orthopedic Institute has repaired more than 3000 rotator cuff tendon tears using arthroscopic visualization, consistently fixing the tendon edge a few millimeters lateral to the supraspinatus footprint adjacent to the articular cartilage. We always use a single row of suture anchors with 2 and often 3 sutures per anchor in an effort to obtain the strongest possible repair with the least possible tension on the construct. In postoperative follow-up magnetic resonance imaging examinations, we commonly observe that the footprint of the rotator cuff completely regenerates to cover the greater tuberosity despite having been completely debrided of all soft tissues at the time of the repair. This paper examines the important contemporary knowledge of biologic factors relevant to the basic science of tendon healing and discusses a study evaluating dynamic blood flow imaging of the healing cuff using contrast ultrasound and magnetic resonance imaging, and presents several surgical biopsies. Finally, we present a simple method for initiating bone marrow egress from the proximal humeral metaphysis, and offer pertinent clinical and scientific data to illuminate the importance of optimizing this natural healing process made available by a robust bone marrow clot that we call the ‘‘Crimson duvet.’’