Gaertner was born on January 16, 1980, in Kitchener, Ontario, Canada to parents Diana and Jonathan.

[5] After returning to the University of Illinois at Urbana–Champaign with a gold medal,[6] he helped the Manitoba Rolling Thunder win their first Canadian Wheelchair Basketball League championship title.

[7] In 2002, he was one of four students who received the Wooddy Scholarship Award as someone who earned both academic and athletic acclaim.

[8] Later, he helped the Winnipeg Thunder win their third consecutive Canadian Wheelchair Basketball League championship title.

[9] In 2004, Gaertner was named to Team Canada to compete at the 2004 Summer Paralympics[10] where he won gold.