The current patients required high flexion total knee arthroplasty (TKA). We hypothesized the patients who would get the high rotational angle just after TKA could gain high flexion knee 1 year after TKA. Sixty-three patients (average age: 70.6 years) were examined. In order to examine between the intraoperative rotational angles and the gained flexion angles after TKA, the patients were divided into two groups: the H group (more than 120°) and the L groups (less than 120°) by the gained flexion angles. The relationship between the flexion angles at 1 year after surgery and the intraoperative rotational angle had no significant correlation. But the rotational angles in the L group tended to be higher than the ones in the H group, and at only 30°, the L group gained significantly more rotational angle than the H group. These results might show that a tighter rotational stability induces a gain of higher flexion knee after TKA.