Resolution of Patellofemoral Bone Marrow Edema and Subchondral Cysts on MRI Post a Single Autologous Fat-Derived Expanded Mesenchymal Stem Cell Therapy

Bone marrow edema and subchondral bone cysts are frequent findings in the various stages of knee osteoarthritis. Typically seen on MRI imaging, once the degenerative process starts, it progresses to severe osteoarthritis and eventually requires knee replacement over time. Herein we report a case of a fifty-four-year-old salesperson who enjoys active sports. He presented with symptomatic right knee osteoarthritis; an MRI scan revealed multiple patellofemoral subchondral bone marrow edema and subchondral cysts with a medial meniscus tear and both medial and patellofemoral cartilage loss together with large baker cyst and synovitis. He failed ultrasoundguided steroid injection but responded dramatically to a single dose of autologous fat-derived expanded mesenchymal stem cells (MSCs) combined with platelet-rich plasma (PRP). He became symptoms-free three months post the therapy. Nine months following the treatment, he remains asymptomatic; a repeat MRI showed a tiny baker cyst and significant reduction of synovitis due to an anti-inflammatory effect of MSCs. A follow-up MRI thirty-three months post-therapy revealed full resolution of both bone marrow edema and multiple subchondral patellofemoral bone cysts. This case represents a successful clinical and radiological outcome following a single expanded mesenchymal stem cell therapy for knee osteoarthritis.