Temporary knee locking with mild pain

Patient: Sir i had a knee twist on 28 june 2014 after two month still i can do my daily life but i have a temporary locked knee when i bend it till my hips or too tightly and after 2-3 minutes it frees and suddenly i have no painmy MRI shows no meniscal tear

Symptoms: Temporary locking of knee after bending to zero angle or zero angle
and no problem in straithting after my knee frees

Doctor: