Evaluation of healing process of bone allograft with bone scan

1386 Objectives The resorption of the femur head and acetabulum is an important complication of the hip surgery. In these cases reoperation is needed with devitalised structural grafts from bone banks. Our aim was to follow the healing process of implanted structural bonegrafts. Methods 43 patients were recruited to our prospective study, who underwent a hip surgery with graft implantation. Tc99m MDP three phase bone-scintigraphy and SPECT were performed in 4 weeks, then 6 and 12 months after the surgery. Patients with trauma and proved infection of the hip during the follow up were excluded from the study. For quantitative measurement we used ROI (region of interest) analysis, the maximum activity of graft region was compared with the maximum activity of the reference region (ROIgraf/ROIref). In case of SPECT 2D viewers were synchronized with a 3D MIP, where the region of the surgery could be easily detected due to the increased uptake. We pointed the high uptake region in the 3D MIP, and the program determined its position in the 2D viewers. Definition of two 3D freehand ROI series over the slices of the SPECT was performed. Data were analysed statistically with Wilcoxon test. Results The ratio of the ROIgraf to ROIref showed decreasing tendency both on planar and SPECT study during the follow up period. Significantly lower ratio was found at third follow up examination compared to the first examination (p Conclusions Based on our study bone scintigraphy seems to be the eligible method to follow the remodelling process of graft implantation. The recommended timing for the evaluation of the graft healing process is at least 12 months after the surgery. Longer follow up is needed to validate this method in order to prove viability of the structural grafts