Objective      To investigate the clinical results and complications of total knee arthroplasty (TKA) in senile patients at different ages.       Methods      A prospective cohort study was carried out on decision making and clinical outcomes for 102 patients (mean age

75 years) with severe OA of the knee with symptoms inadequately controlled with conservative treatments. The patients were divided into 3 groups according to their age

including group A (60 to 70 years

n=51)

group B (70 to 75 years

n=33)

and group C (75 years

n=18). Osteoarthritis symptoms and functional status were assessed at baseline and at 12 months. Postoperative symptoms and function were assessed in 6 weeks

6 months

and 12 months after surgery.       Results      The mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 96 in group A

96.7 in group B and 95.7 in group C based on a 100-point scale. At 12 months

WOMAC scores was improved by 24 points in the group A

37 in group B

and 13 in group C (P0.01). The improvement was significantly different among the 3 groups

with that of group B most significant. SF-12 score and ADL score showed similar results.       Conclusion      For osteoarthritis patients with age from 70 to 75

joint replacement is good in functional recovery and improvement. So age ranging from 70 to 75 is a good time for this surgery.