What is ewald lienen injury?

Ewald Lienen is a retired German footballer who suffered a career-threatening injury on 31 October 1981, while playing for SV Werder Bremen against 1. FC Kaiserslautern in the Bundesliga. He suffered a laceration to the left cheek from an opponent's boot, which required 18 stitches and left him with a permanent scar. The incident is widely considered to be one of the most gruesome injuries in football history. Despite the severity of the injury, Lienen went on to enjoy a successful career, playing for several clubs in Germany and Spain, as well as managing several teams after retirement.