The importance of roentgenological and scintigraphic studies in patients with and without thigh pain following cementless PCA hip endoprosthesis

Abstract

Persisting postoperative thigh pain is a common problem in cementless total hip prostheses occurring in a rate of about 15-20% of the patients. The reason for that phenomenon has not become clear so far. In a clinical, radiological and scintigraphic study 70 patients with 81 PCA cementless total hips were randomized in groups with (n = 34) and without significant thigh pain (n = 36). All patients underwent clinical examination including a standardized questionnaire, x-ray and 3-phase bone scintigraphy. Quantitative assessment of Tc-99m-MDP uptake was made. In the group of patients with persisting thigh pain the scintigraphic analysis showed an significantly increased uptake at the tip and the medial and lateral femur. These findings could not be correlated with clinical loosening of the prosthesis. Slight or moderate uptake in the area of the greater and lesser trochanter as well as the tip was a common finding in PCA prosthesis in all patients. In the radiological analysis no difference between both groups was evident. The study showed that patients with thigh pain after cementless PCA total hip prosthesis have specific regions of significantly increased uptake in scintigraphic examination (tip, medial and lateral femur), which cannot be correllated with clinically or radiologically signs of loosening. The morphologic reasons for the thigh pain remain unclear.