To evaluate changes in serum levels of bone turnover markers during the first year following a total hip or knee arthroplasty (THA or TKA, respectively).
34 women and 13 men (mean age, 68 years) with idiopathic hip or knee osteoarthritis underwent elective THA or TKA. The serum levels of (1) osteoprotegerin, (2) nuclear factor-kappa B ligand (RANKL), (3) osteocalcin, and (4) bone-specific alkaline phosphatase (b-ALP) were determined in each patient on preoperative day 1 and postoperative day 3 and 7, and month 2, 4, 6, 8, 10, and 12.
All 4 markers changed significantly over the 12-month period. At month 12, values of all markers did not return to their preoperative levels uniformly. At month 8, the serum levels of osteoprotegerin, osteocalcin, and b-ALP remained higher than their respective preoperative values. The serum levels of RANKL gradually decreased after month 2, rendering this marker a potential index for fixation.
Bone turnover markers change following arthroplasties. Postoperative month 8 seems to be a milestone in the normal course of these markers.