Patellar apprehension test

Written by Dr Sheila Strover on March 14, 2025

The patellar apprehension test is performed to confirm the doctor's suspicion of an underlying patellar instability, such as patellar subluxation or dislocation.

The patellar apprehension test is positive if the patient resists the surgeon's manoeuvre.

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How to perform the patellar apprehension test

The patient lies face up on an examination couch, with the surgeon perched on the lower end, holding the patient's ankle with the foot off the couch and the knee flexed to 45 degrees.

With the other hand the surgeon holds the patella between finger and thumb and, using moderate force, tries to push it laterally out of the groove of the underlying femur. A positive test is when the patient puts out a hand to stop this movement.

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What is the value of a positive patellar apprehension test?

Because a patient may know that there is something wrong with the knee, but may have difficulty describing the incidents being experienced, this test helps the doctor to decide if patellar instability is playing a part in the symptoms.

"...though the PAT can be used to provide a provisional clinical diagnosis of patellar instability, formal functional assessment and imaging should be performed to confirm the diagnosis."

Diego Agustin Abelleyra Lastoria et al

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A-Z Keywords -

Patellar subluxation, Patellar dislocation, Patellar instability, Patellofemoral instability, Patellar dysplasia, Trochlear dysplasia, Patella alta, Hypermobility

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