INCREASED URINARY CROSS-LINK LEVELS IN ASEPTIC LOOSENING OF TOTAL HIP-ARTHROPLASTY

The diagnosis of aseptic loosening in total hip arthroplasty is predom inantly based on clinical and radiographic evaluation. Loosening is us ually associated with increased bone resorption at the interface. In t his study we wanted to evaluate the diagnostic value of bone markers i n aseptic loosening. We compared 50 patients with proven component loo sening during surgery with 50 age-, sex-, and implant-matched patients without clinical or radiological signs of loosening. We measured seru m markers of bone formation (bone-specific alkaline phosphatase, osteo calcin [OC], procollagen type I propeptides) and bone resorption (coll agen n-telopeptide [NTX], deoxypyridinoline [DPYD], pyridinoline [PYD] ). We found significantly increased levels of NTX, DPYD, PYD, and OC i n the loosening group. The other markers showed no significant differe nce between both groups. We conclude that determination of urinary cro sslinks may offer a new and valuable diagnostic method in the detectio n of aseptic loosening in total hip arthroplasty.