Abstract
Aims: The aim of this prospective study was to measure changes of bone mineral density (BMD) in the proximal tibia after cemented total knee arthroplasty (TKA) in osteoarthrotic knee joints. Methods: Sixty-nine patients were scanned by dual-energy x-ray absorptiometry (DXA) within a week postoperatively, at 3, 6 and 12 months follow-up. Results:Medial metaphyseal measurement region on interest (ROI) showed a signiþcant decrease in BMD values in preoperatively varus knees joints (p < 0.0005). In preoperatively valgus knees there was a slight non-signiþcant increase in BMD (p=0.184). At the baseline the medial ROI BMD differed from each other signiþcantly in these alignment groups (p= 0.023, independent samples T-test). Alignment correction in the both groups showed bone remodeling towards similar actual BMD values. Finally medial and lateral BMD values were also more similar suggesting that the bone became equally strong on both compartments of metaphysis. We could not trace the effect of increasing AKS score values to the bone remodeling. Conclusions: We suggest that loading effect on bone may be a major profound bone remodeling factor. Its clinical value can not be ignored nor determined by other changes in knee joint status and function. These results conþrm the clinical importance of recreating the proper valgus alignment of the knee joint in TKA operation, which offers possibly better proof for the longevity of the tibial component.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
