During World War I he was conscripted into the German army, fought on the eastern front, and was taken captive and held in Tashkent. In 1918, he made his way through Finland and Sweden to Poland. He took part in the Polish-Bolshevik war as a medic. After studying medicine in Münster, Kraków and Poznań and obtaining the degree of doctor of medical sciences, Raszeja worked at the university hospital in Poznań. In 1928, he was one of the five founding members of the Polish Orthopaedic and Traumatic Society. Raszeja received his postdoctoral diploma in 1931 and became the director of an orthopaedic hospital in Swarzędz. At the same time, he headed an orthopaedic polyclinic in Poznań. Raszeja led to the reopening of the orthopaedic hospital of the Poznań University in 1935 and took over its management, an action that a year later resulted in him being awarded the title of professor. He later belonged to the Polish Academic Corporation Baltia.