Imaging
In a patient with knee symptoms (pain, swelling, locking, catching, popping, giving way) and/or signs (tenderness, effusion, loss of motion, crepitus), x-rays (including AP, lateral, sunrise/Merchant, and tunnel views) are an option.

Rationale
Patients with an OCD lesion often present with complaints of knee pain and swelling.  In addition, patients may note sensations of locking (motion of the knee is halted), catching (motion is partially inhibited), popping, or giving way.  Physical examination may reveal tenderness, effusion, loss of motion, or crepitus. 

AAOS conducted a systematic review that identified one diagnostic study which evaluated the diagnostic performance of clinical examination with radiographs and of selective MRI in the evaluation of intra-articular knee disorders by comparing these findings with arthroscopic findings.40 Clinical diagnosis was made on the basis of history, physical examination, and standard radiographs (AP, lateral, Merchant, and tunnel views). MRI studies were ordered selectively on the basis of clinical discretion.  Arthroscopic evaluation was performed in the subset of patients that required surgery, based on clinical diagnosis and MRI findings if an MRI was performed.  The clinical diagnosis (from the initial visit), MRI diagnosis (from the MRI report), and the arthroscopic diagnosis (from the operative report) were retrospectively reviewed and compared. Since only a subset of all patients that underwent evaluation of intra-articular knee disorders proceeded to arthroscopic evaluation, this diagnostic study does not universally apply the reference standard of arthroscopy.  Consequently, we assessed this retrospective diagnostic study without a universally applied reference standard as a Level II study. Since only a single study is available to support this recommendation, the strength of recommendation is limited.