The doctor will first take a history from the patient to learn about
the location of the pain, when it began, and whether it is injury-related.
Knowing the patient's activity level, whether there is instability,
and what motions increase pain help the doctor make the diagnosis.
In the physical examination the doctor will:
usually be able to reproduce the symptoms by pressing on the
kneecap, particularly when the knee is bent and then straightened.
check for tenderness and patellar motion
assess alignment and flexibility
evaluate the muscular strength and coordination of the leg
X-rays show the bony structures of the knee, permitting the doctor
to rule out:
loose bodies (bone fragments in the joint)
varus or valgus mal-alignment (bow-legs or knock-knees)
infection or a bone tumor
An MRI (Magnetic Resonance Imaging) or TEC (Technician 99 Radioisotope)
Scan may be recommended if symptoms persist after conservative (non-operative)
treatment. Both of these studies can show bone changes such as:
a bone bruise or stress fracture
cartilage loss or deterioration
infection or a tumor
An MRI can also reveal:
the condition of the ligaments, cartilage, and menisci
a swollen plica (a normal fold of tissue which can be painful when it becomes inflamed and enlarged).
Tendonitis or partial tearing with nodule formation in the patellar tendon