Serum Intact-Parathyroid Hormone Level following Total Knee Arthroplasty

Purpose. To evaluate short-term parathyroid hormone (PTH) secretion following total knee arthroplasty (TKA). Methods. 119 Caucasian postmenopausal women aged 49 to 81 (mean, 69.8) years who underwent TKA for end-stage knee osteoarthritis were included. Serum levels of intact-PTH, calcium, phosphorus, and creatinine were evaluated pre- and post-operatively (on days −1 and 7). Creatinine clearance was also calculated. Results. In 67 of the patients, serum intact-PTH levels decreased after TKA; this sample proportion was not significant (p=0.82). In 16 of the patients, such levels elevated abnormally (above normal range). In the remaining 36 patients, such levels elevated within the normal range. Therefore, the mean serum intact-PTH level of all patients increased slightly after TKA (45.4 vs. 45.3, p=0.162). The serum intact-PTH level did not correlate to body weight (r=–0.045, p=0.624), patient age (r=–0.061, p=0.508), serum creatinine level (r=0.084, p=0.366), and clearance of creatinine (r=–0.037, p=0.692). Conclusion. In most postmenopausal women, the serum intact-PTH level decreased moderately following TKA, but in some, the level was abnormally elevated. This may interfere the prosthesis incorporation process.