Sequential Analysis In Periprothetic Uptaking Of Bone Scanning After Cementless Total Hip Arthroplasty In Asymptomatic Patients

Objective To establish bone scan baseline patterns for total hip arthroplasty , comparison with baseline ratios can provide the best source of reference to evaluate postoperative progress . Methods Three hour delayed bone images were obtained after injections of 740 MBq of Technetium-99m Mythylene Diphosphonate. We used phrase-III images obtained with a high revolution parallel-hole collimator gamma camera(Varicam , GE) and measured the activity in various zones using a specially designed computer program . In 30 asymptomatic hip arthroplasties, we performed isotope scans at intervals from 1 to 12 months after operation. Results All the periprosthetic zones showed high activity ratios at 1 months with a considerable reduction by 3 months. From six months ontowards, the uptake ratio of periprosthetic zones suggest a stabilization in activity. There are no significant differences among the uptake ratio of three acetabular zones. The uptake ratio of femoral zones decreased significantly between 1 and 3 months after surgery. After 6 months, there is no significant change. The highest activity was seen in the great trochanter area( I zone), and then in descending order the less trochanter(VII zone), the tip(IV zone), the femoral stem. Conclusions In the case ofcementless arthroplasties, complications may be suspected i bone uptake is high after 6 months. However, for cementless arthroplasties, such a basic guideline as bone scans in cementless arthroplasties had not been provided a similar criteria. We tried to provide reliable evaluative criteria by doing a quantitative bone scan. It may be a helpful diagnostic procedure for evaluating postoperative progress when used in conjunction with clinical symptoms and radiological examinations.