Amnion-Based Injections in the Shoulder for Adhesive Capsulitis and Osteoarthritis

Amnion injections are commonly performed by community orthopaedic surgeons for many conditions, including osteoarthritis, rotator cuff tears, tendinitis, and others. Human placental tissue has been reported to contain biochemical and immunologic properties that play key roles in regulation of the inflammation-healing cycle. Amnion-chorion membrane has been shown to contain high concentrations of collagens, transforming growth factor beta suppressors, and inhibitors of matrix metalloproteinases that provide strong scaffolding, suppress scar formation, and regulate tissue remodeling, respectively. The amnion injection is a morselized, flowable tissue allograft derived from human amniotic tissues. The amniotic tissue comes from placenta, donated by pre-screened healthy women undergoing scheduled C-sections. It is processed into a form that can be injected.

Similarly, in a recent study injection of micronized dehydrated human amnion-chorion membrane slowed the development of cartilaginous lesions and led to a decreased number of erosions in a rat model of osteoarthritis. There is also an emerging body of literature investigating its use in osteoarthritis of the knee, with promising early results. In one study human amniotic suspension allograft was injected into patients with symptomatic knee osteoarthritis. No significant reactions were noted and the feasibility of injection for treatment of the osteoarthritis in the knee was demonstrated. Another study found that human amniotic fluid had a positive effect on tibia fracture healing through a rat model. In an osteoarthritis model, injection demonstrated attenuation of cartilage destruction and significant increases in cartilage thickness and volume. Finally, patients with plantar fasciitis noted significant improvement in symptoms, and American Orthopaedic Foot and Ankle Society Hindfoot scores (pain, function, alignment) compared to controls. These studies suggest the safety and efficacy of amnion-based injections in treating specific orthopaedic pathologies.

Osteoarthritis and adhesive capsulitis are two common pathologies of the shoulder. There is a variety of options for conservative management including physical therapy, pain medications, and injections, but no evidence that places one modality over another. The purpose of this study is the evaluate the effectiveness of amniotic fluid injection in treating these pathologies. In this study intra-articular amnion will be injected into the shoulders of patients with moderate to severe osteoarthritis and patients with frozen shoulder and assessing pain, function and range of motion over time.