Dr. Oshima is an orthopaedic surgeon who holds the title of Associate Professor in the Department of Orthopaedic Surgery at Nippon Medical School in Tokyo. His orthopaedic training included a residency and a PhD course at the Department of Orthopaedics, Kyoto Prefectural University of Medicine, a research fellowship at the Department of Orthopaedic Surgery, University of California San Diego and a visiting professorship at the Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases.

He has been a long-term member of the Japanese Orthopaedic Association and is a member of various other orthopaedic societies including the Japanese Society for Replacement Arthroplasty and the Orthopaedic Research Society in the US.

His PhD study involved the regeneration of articular cartilage using mesenchymal stem cells. His recent clinical research involves studies of osteoarthritis of the knee, cartilage repair, knee biomechanics, and knee arthroplasty. He received the ISTA Young Investigator award in 2018 as a co-author.