The relationship between ambulation ability before surgery and the D-dimer value after total hip arthroplasty: the evaluation of ambulation ability by the timed "Up & Go" test.

We examined whether ambulatory ability before surgery might influence the post-operative D-dimer level after total hip arthroplasty (THA). One hundred two patients with hip osteoarthritis receiving THA were included in the current study. The patients were all female, and their ages ranged from 45 to 81 (average 65.0 +- 9.3 years). Age, operated side, body mass index (BMI), disease duration before surgery, pre-operative pain evaluated by visual analogue scale (VAS), total cholesterol value, maximal circumference of the lower leg of the operated side, and timed "Up & Go"test (TUG) before surgery, were retrospectively investigated to examine their relationship with D-dimer levels on post-operative day 7. Patients were divided into 2 groups according to the D-dimer value: over 10 microg/ml (Group D), and under (Group N). Patients in group D (N= 52)were older, had a higher BMI, and had less ambulatory ability than patients in group N (N= 50). As age showed a relationship with the D-dimer value on the 7th day and TUG results, patients in the 2 groups were further subdivided into 50's, 60's, and 70's age brackets. In the 50's bracket, patients in group D had higher BMI than patients in group N, but time for TUG was not significantly different. In the 60's and 70's bracket, patients in group D had less ambulatory ability than patients in group N, but the time for TUG was not directly correlated with the D-dimer value. The results suggest that pre-operative low ambulatory ability in patients with osteoarthritis over 60 years might influence the postoperative D-dimer after THA, indicating the potential risk for post-operative deep venous thrombosis.