The striker is currently on loan at fellow Championship club Bolton Wanderers and has improved his goalscoring form since moving to Lancashire.
He only scored once in over 20 appearances for Boro before being loaned out in January, since going on to score five goals in 11 appearances for Wanderers.
"I am very happy with the way he has been playing," Sky Sports News quotes Karanka as saying.
"When we sat down together to discuss what was going to happen earlier in the season, we came up with the solution of him going to Bolton on loan because we all wanted the same thing.
"It was very important for him to go somewhere and score goals so he could get more confidence. I am pleased that has happened, and I know more now than I knew at the beginning. I am happy, Lukas is happy and Bolton are happy. We will leave it until the summer."
Jutkiewicz has been a Boro player since joining from Coventry City in January 2012.