EMPLOYEE CLAIMS HIS KNEE POPPED OUT A YEAR AGO BUT HE GOT IT BACK IN PLACE HIMSELF. HE SAYS IT HAPPENED AT WORK BUT HE DID NOT REPORT IT. SINCE THAT TIME IT HAS GONE OUT SEVERAL TIMES. HE H AD SURGERY ON HIS KNEE 8-22. HE WORKED AT HIS REGULAR JOB UNTIL THE DAY OF SURGERY.