Contact thermography as a screening test for deep venous thrombosis following major hip surgery

Contact thermography is a non-invasive, easily handled, and inexpensive investigation for the diagnosis of deep venous thrombosis (DVT) in the lower limbs. In this study 56 patients with total hip replacement were screened for DVT by contact thermography, using bilateral ascending phlebography as reference procedure. Examinations were performed on the seventh postoperative day. All thermograms were evaluated blindly and independently at the end of the study. Phlebography revealed unilateral DVT in six patients. Only two had corresponding findings at thermography, giving four false negative results. Moreover, 14 false positive thermograms were found. Based on the number of legs investigated, the nosographic sensitivity and specificity thus were 33 and 87 per cent, respectively. It is concluded that contact thermography is of no value as a screening test for DVT following major hip surgery.