A patient gives a H/0 twisting strain and locking of the knee joint, the most likely diagnosis is -
Clinical features of meniscal tear

The patient is usually a young patient who sustained a twisting injury to the knee on the sports field.
There is a classical history of twisting injury with swelling appears some hours later or perhaps the following day (in comparison to hemarthrosis, in which swelling develops immediately).
There is recurrent pain. Later on, pain becomes persistent.
There is recurrent locking of the knee, i.e., the knee is locked in partial flexion with the inability to extend the knee for the last few degrees.
Avulsion of tibial tubercle
Meniscal tear
Tearing of lateral collateral ligament
Tear of anterior cruciate ligament