Kim Kardashian West had to explain Caitlyn's transition to Lamar Odom

Kim Kardashian West had to explain Caitlyn Jenner's transition to Lamar Odom.

Lamar suffered a brain injury when he collapsed at a brothel in Nevada following an alcohol and drugs binge last year and his confusion and memory loss meant he struggled to understand that his former father-in-law Bruce Jenner had underwent a gender transition to become Caitlyn.

Speaking on an upcoming episode of 'Keeping Up With The Kardashians', Kim, 35, told Caitlyn, 66: "He saw something on the news about you, and he was a little confused, so I had to like explain it to him. I was like, 'Well, it's Caitlyn now.' And he was like, 'What?'"

Caitlyn responded: "I know Khloe [Kardashian - Lamar's estranged wife] tried to explain it to him a couple of times, but at that point I don't think he was getting anything."

Speaking in November about Lamar's recover, Khloe said: "He's learning how to walk again and feed himself again and put sentences together. It's a long, long road ahead.

"He's really confused a lot. Sometimes he knows who the president is and his birthday, and sometimes he thinks he's 26. I say, 'I bet you wish you were 26, so do I!'"

However, Lamar, 36, has gone on to make a remarkable recovery. He has been released from hospital and is living in a house in the same estate as Khloe.