KTRK-TV, Houston, said Michael Latrique moved to protect a co-worker during a late night robbery in mid-January.
As he did, the thieves, who got away with $200, grabbed him by the leg and pulled him through a door, where his femur broke.
"I heard was a pop, and the next thing I know my leg was just swelling," Latrique said.
However, Latrique was denied insurance because a mandated drug test at the hospital discovered evidence that he had smoked marijuana before the incident.
Latrique said he had smoked marijuana a few days before the robbery, but not on the day of the robbery.
His employer, Sonic, a hamburger franchise, has its own insurance plan, so it opts out of workers compensation, KTRK reported.
Latrique says he is in constant pain.
The owners of the restaurant said the decision was the insurance company's. The insurance company said it was based on the company's rules. The company's public relations office said it was out of their hands.
In a statement the company said it could not say much given the possibility of a lawsuit. Its statement also suggested it agreed with the drug-test rule.