Kobe Bryant is expected to miss about six weeks with an injured left knee.
The Lakers said Thursday that an MRI showed Bryant has a fracture of the lateral tibial plateau of his knee.
The team said Bryant had hyperextended the knee in Tuesday night's game at Memphis.
The injury is the latest setback for the Lakers star, who had only returned to the court on Dec. 8 after nearly eight months away because of a torn Achilles tendon.
Los Angeles had signed the fourth-leading scoring in NBA history to a two-year contract extension last month. Bryant's new deal is reportedly worth $48.5 million and takes him into his 20th season with the Lakers.
Bryant was hurt in his sixth game back when he matched his season high with 21 points. He went to the floor with 3:25 left in the third quarter of Tuesday night's 96-92 win at Memphis. He stayed on the floor briefly before standing up, and Bryant bent over at the waist as he flexed his left leg back and forth. He walked to the bench with trainer Gary Vitti but returned to the floor following the timeout.
He hit a deep 3-pointer late in the fourth quarter to help clinch the win and finished playing more than 32 minutes. Bryant said after the game that he kind of twisted his knee but it felt all right.
"I just hyperextended it," Bryant said when asked to describe what happened on the play. "I tend to hyperextend my knees every now and then."