A Randomized Trial of Cortisone Injection Versus Bone Marrow Aspirate Injection Therapy for Glenohumeral Osteoarthritis

Glenohumeral joint (GHJ) osteoarthritis (OA) is a painful, progressive and debilitating condition that impairs quality of life. Currently, the only "cure" for arthritis is total joint replacement. This is a major operation that carries with it significant risks including infection, stiffness, limited range of motion, peri-prosthetic fracture and loosening. Furthermore, there are permanent post-operative restrictions, and in young or active people there is a significant rate of early revision surgery. Therefore, the goal of early shoulder OA management is symptom control, and postponement or prevention of the need for joint replacement.

Initial management options include physical therapy, pain-control medications, and intra-articular injections. Corticosteroid injections are the most commonly utilized injectables used in GHJ OA, with previous studies reporting good, short term pain relief and clinical improvement with corticosteroid injections for shoulder OA. However, corticosteroid injections may damage the collagen matrix of tendons and ligaments around the shoulder with repeated injections. Intra-articular hyaluronic acid (HA) injections have been proposed as an alternative to corticosteroid injections, and have demonstrated a clinically significant improvement in pain and function, albeit with a limited effect size.

Bone marrow aspirate concentrate (BMA) injections is a relatively recent option for the treatment of OA. BMA is a biological product that is produced through the centrifugation of the patient's own bone marrow, producing a cellular equivalent to iliac crest bone graft. This aspirate has been shown to contain, among other nucleated cells, mesenchymal stem cells (MSC's) and hematopoietic stem cells (which can directly convert to stromal MSC's).Furthermore, this minimally invasive procedure can be conducted as an outpatient procedure, saving operating room time.

Preliminary studies on intra-articular knee injections of BMA for early OA have reported statistically significant benefits in improved pain scores and function, with few adverse effects. The mechanism of action is likely through paracrine effects exerted by MSCs with the upshot being anti-inflammatory and potentially regenerative capabilities. These results are encouraging for the use of BMA in the shoulder, which is a non-weight bearing joint. Therefore, the investigators believe that the clinical improvements seen with BMA injections for knee OA will also be seen in the shoulder to an equal or greater extent.

To date there are no trials investigating injectable stem cell therapies in the shoulder. The investigators aim to conduct a randomized controlled study to test the safety and efficacy of BMA injections for the treatment of early to mid-stage GHJ OA.