On 12/14/17 EE stated EE felt a pop in EE's left knee & did not recall a specific event at the time. Seen by site medic, referred to ER, X-rays negative, full work release issued. 1/3/18 seen Orthopedic doctor, MRI done, tear was found in meniscus tendon, full work release issued, surgery set for 2/13/18. Employee stated this was chronic not a event & first shift missed 2/14/18