Former Yankees center fielder Elliott Maddox struck out in New York's top court when it dismissed his $12 million lawsuit against New York City and others for a career-ending knee injury.

In a 6-0 ruling, the state Court of Appeals upheld a lower court's decision that dismissed the Maddox suit against the city, as owner of Shea Stadium; the Metropolitan Baseball Club Inc., the lessee of the stadium; the New York Yankees; the maintenance company for Shea Stadium, and The American League of Professional Baseball Clubs, as employer of the umpires.

The court said Maddox was aware of the wet and muddy condition of the playing field at Shea Stadium (the Yankees were playing there because their stadium was being renovated) on June 13, 1975, the night he was injured. "His continued participation in the game in light of that awareness constituted assumption of risk as a matter of law," wrote Judge Bernard Meyer . . .

Roger Maris, the former Yankees slugger, has become a patient of one of the nation's leading researchers in experimental cancer treatment.

Dr. Robert Oldham of Franklin, Tenn., said earlier this week, "We are proceeding with some research for Mr. Maris that will lead up to some treatment. He has been under care and ill for some time."

Maris declined comment on the treatment or his condition, his daughter, Suzanne Maris, said.

Maris, a two-time American League most valuable player and the holder of the major leagues' single-season home run record of 61, is 51 and owns a beer distributorship in Gainesville, Fla.