TestDescriptionFindingSensitivity (%)Specificity (%)Positive predictive value (%)Negative predictive value (%)
Tap testWith the patient standing, a hand is placed over the SFJ, and the LSV is tapped at the level of the knee with the other hand.A palpable transmitted impulse denotes that the LSV is distended with blood.
The SFJ is then tapped and the presence of a retrograde, palpably transmitted impulse at the knee indicates incompetence of valves between the SFJ and the LSV, with reflux in the proximal LSV.
18927047
Cough testWith the patient standing, a finger is placed on the thigh over the SFJ.A palpable thrill or impulse on coughing is indicative of an incompetent SFJ.59676438
Perthes testWith the patient standing, a tourniquet is applied below the knee.
The patient is directed to complete 10 heel raises.
If the varicosities empty, the site of reflux is above the tourniquet.
If the veins remain distended, the site of reflux is below the tourniquet.
97205513
Trendelenburg testWith the patient in the supine position, the affected leg is elevated to 45 degrees to drain the varicosities.
A tourniquet is applied just below the SFJ, and the patient is directed to stand.
Failure of the varicosities to fill indicates that the SFJ is the site of reflux.91155238