Maladenis began his career in Skoda Xanthi, attracting the interest of Panathinaikos and AEK Athens.
Despite the injuries he had, he slowly made his presence felt, competing in many positions in the lineup, mainly in the midfield and offense.
He also played an incredible match against Iraklis in Kaftanzoglio Stadium, completing a hat-trick in AEK's victory with 2-3 which secured them in second place and sent them in next season's UEFA Champions League qualifiers.
His best moment of his career was arguably the goal against Real Madrid in a Champions League game at Nikos Goumas Stadium on 2 October 2002.
Maladenis made his team debut a few days later, scoring in a 1–0 friendly win against Lokomotiv Plovdiv.