Employee kneeled down to look at controls on a vac truck, EE felt EE's right knee pop. Conservative care until September - MRI was done. Then referral to ortho for MRI results. No tear, but the ortho Dr. ordered PT, making this a recordable injury, reason for delay in reporting. On 9/27 - PT was ordered but on 10-11 it was confirmed that PT was necessary along with injections.