QUANTITATIVE-ANALYSIS OF TECHNETIUM-99M-METHYLENE DIPHOSPHONATE UPTAKE IN UNILATERAL HYDROXYAPATITE-COATED TOTAL HIP PROSTHESES - FIRST YEAR OF FOLLOW-UP

A prospective study was performed on 80 patients who had undergone a u nilateral hydroxyapatite (HA)-coated total hip arthroplasty to establi sh the normal periprosthetic uptake of methylenediphosphonate (MDP) as a function of implant age. Methods: Patients were imaged periodically while they were asymptomatic at 1, 3, 6 and 12 mo postoperatively. Qa ntitative measurements were performed with a region of interest (ROI) technique. The HA-coated and uncoated areas were marked in comparison with the normal contralateral femur. The uptake ratios of the MDP were determined postoperatively in the following 12 mo. Results: It was fo und that a decrease of the uptake ratios occurred in all ROIs. However , for the HA-coated areas, the uptake ratios still remained raised as a result of bony ingrowth. Conclusion: The results of the first year o f follow-up were considered to be a normal database that will be used as a reference when the same group of patients are followed up to 5 yr postoperatively to detect any potential modes of failure of the impla nt.