A D.C. Superior Court judge yesterday ordered the District government to pay $338,000 to a 41-year-old Southeast bricklayer whose left leg was amputated following an improper diagnosis by D.C. General Hospital doctors.

Judge Leonard Braman made the award to Louis J. Walker, who has been unable to hold a job for an extended period since his leg was amputated above the knee almost four years ago.

During the three-day, nonjury trial, Judge Braman admitted into evidence a 25-minute videotape, prepared by Walker's attorneys, that showed the difficulty Walker has in performing routine daily activities.

The judgment marked the second time in three weeks that a Superior Court judge has found the city-owned D.C. General Hospital negligent in the care of a patient.

On Feb. 25, Judge Fred L. McIntyre ordered the city government to pay $950,000 for the lifelong care of a five-year-old Oxon Hill boy who suffered severe brain damage after hospital doctors failed to properly treat him for dehydration.

In yesterday's case, Walker charged the city was negligent because three hospital doctors failed to determine that he had a blood clot in his left leg when he came to the hospital emergency room Sept. 12, 1976, suffering from "acute pain."

According to Walker, he waited three hours before he saw a doctor. After an examination by three physicians, including a surgeon, he was discharged and told to return three months later for neurological treatment, he said.

Two days later, the pain persisted, Walker went to the Greater Southeast Community Hospital where doctors removed a blood clot from behind his left knee, according to court papers. Walker's leg was amputed Oct. 2.

The city denied that the hospital's doctors have been negligent. The city also argued that "it cannot be opined to be a reasonable medical probability that (Walker) would not have had his leg amputated had an accurate diagonosis been made."

Walker, who had been earning $8.50 an hour as a bricklayer, has incurred about $20,000 in medical bills, according to court papers.

Since losing his leg, Walker has trained as a television repairman but has found little work and is now planning to obtain a graduate equivalency degree and study to be a draftsman, according to court papers.