Complications following biologic therapeutic injections: a multicenter case series

Abstract Purpose The aim of this study was to describe the complications that occur following biologic therapeutic injections. Methods We queried physician members of the Biologic Association™, a multidisciplinary organization dedicated to providing a unified voice for all matters related to musculoskeletal biologics and regenerative medicine. Patients included in this study must have (a) received a biologic injection, (b) sustained an adverse reaction, and (c) had a minimum of 1 year follow up after the injection. Patient demographic information, medical comorbidities, diagnoses, and prior treatments were recorded. The type of injection, injection setting, injection manufacturers, and specific details about the complication and outcome were collected. Results 14 patients were identified across six institutions in the United States (mean age 63 years, range: 36 to 83 years). The most common injections in this series were intra-articular knee injections (50%), followed intra-articular shoulder injections (21.4%). The most common underlying diagnosis was osteoarthritis (78.5%). Types of injections included umbilical cord blood, platelet-rich plasma, bone marrow aspirate concentrate, placental tissue, and unspecified “stem cell” injections. Complications included infection (50%), suspected sterile inflammatory response (42.9%), and a combination of both (7.1%). The most common pathogen identified from infection cases was Escherichia coli (n=4). All patients who had isolated infections underwent treatment with at least one subsequent surgical intervention (mean: 3.6, range: 1-12) and intravenous antibiotic therapy. Conclusions This study demonstrates that serious complications can occur following treatment with biologic injections, including infections requiring multiple surgical procedures and inflammatory reactions.