Lennon said the Swedish right-back had been playing through the pain barrier for several months.
But with Sweden failing to reach the 2014 FIFA World Cup Brazil™ and Celtic being eliminated from the UEFA Champions League, the decision was taken to have a medical operation. The 27-year-old Lustig had been in impressive form for Celtic.
"Lustig had surgery, four months," Lennon said. "He had both hips done, so the procedure was a bit more in-depth than first thought.
"We are hoping he will be back March/April time, but he had a lot of work done which makes his recent performances even more remarkable.
"His movement was restricted and he was in a lot of pain after games, so it needed doing. So hopefully he will come back an even better player, which will be brilliant for us."