Yocum was on the staff of the Kerlan-Jobe Orthopaedic Clinic, founded by Dr. Frank Jobe who pioneered the famous surgery in 1974. He and Dr. James Andrews took over Jobe's mantle as the go-to surgeons for this procedure, and he operated on a number of the top pitchers of baseball, including Stephen Strasburg in 2010.
"Dr. Lewis Yocum was a giant in the field of sports medicine. He was an invaluable resource to not only the Angels franchise but players throughout all of Major League Baseball, team physicians and the members of the Professional Baseball Athletic Trainers Society. All of our Clubs relied upon Dr. Yocum’s trusted opinion and judgment. Throughout the last 36 years, the lives and careers of countless players benefited from his pioneering expertise, and he made our game on the field better as a result. On behalf of Major League Baseball, I extend my deepest condolences to his wife Beth, their children, their friends and his many admirers."
Dr. Yocum performed other types of surgery, included the leg surgery that saved the career of Kendrys Morales. He was looking at ways to improve the prospects of recovery from shoulder surgery, and served as an adviser on the Commissioner's panel on concussions.