THE POSSIBLE DIAGNOSTIC-VALUE OF NEW BIOC HEMICAL MARKERS IN ASEPTIC LOOSENING OF HIP ENDOPROSTHESIS

Aseptic loosening of endoprosthesis is the most important problem in t otal hip arthroplasty. The diagnosis of aseptic loosening is based on anamnesis,the clinical findings, the radiography and scintigraphy. Des pite the mul titude of diagnostic possibilities it is still a problem to get an exact and early diagnosis. The process of loosening in the b one interface always leads to a change of bone structure of the surrou nding bone tissue. In a prospective study we measured biochemical mark ers of bone metabolism in serum and urine to evaluate a possible chang e occuring parallel to endoprotheic loosening. 37 patients with severe signs of loosening (later intraoperativly confirmed) and 30 patients without any clinical or radiological signs of loosening (control group ) were included. Gender, age and model of endoprosthesis were similar in both groups. Parameters of bone formation (osteocalcin, alkaline ph osphatase, procollagen I C-terminal extension peptide) and bone resorp tion (Cross-linked n-terminal telopetide) were measured. The cross-lin ked n-terminal telopetide (NTX) was significant increased in the loose ning group (p < 0.001). Of the measured bone formation markers only os teocalcin showed a significantly higher level in patients with endopro sthetic loosening (p < 0.002). All other measured parameters of the bo ne metabolism showed no significant differences between the both group s.Our results show, that biochemical markers can provide relevant info rmation of endoprosthesic loosening. We are now analysing in a prospec tive longitudinal study wheather these parameters are also suitable to detect.arly endoprosthetic loosening.