A growing subset of patients had a TKA with greater life expectancy after reaching age 80[9]. This study was done to address the TKA outcome, the rate of complication, patients’ satisfaction, and mortality after primary TKA in patients age 80 years and older.
The 80 years and older patients frequently had several preoperative medical comorbidities. A history of hypertension and cardiac disease was most common. Belmar et al1 showed that postoperative medical complications often could be linked with preoperative medical conditions. A high rate of complications had been reported in several series of primary and revision TKA in elderly patients[10], [11], [12]. Hosick et al[13] reported that a large number of comorbid conditions were present in patients older than 80 years who had a TKA. In that study, the rate of postoperative medical complications was 7%. In each of these studies, the medical complications were typically transient and rarely compromised the ultimate outcome of the TKA. Then preoperative detailed information obtained from patients and their family members about medical history as well as optimal perioperative patient care is required[14], [15]. However, we could not link the postoperative medical complications to the preoperative medical comorbidities. In our study, the rate of postoperative medical complications was 5%. The preoperative hemoglobin of patients between bilateral TKAs in one stage and unilateral TKAs were not statistic significant (p > 0.05), which showed that the preoperative hemoglobin was not the most important factor in deciding bilateral TKAs in one stage[16].
In the present study, the period of bilateral TKAs hospital stay (23.07 ± 9.20) was longer than the young bilateral TKAs patients[11]. In China, the postoperative self-physical therapy of old adult patients is usually continued until the patients’ ability to walk becomes steady. The delayed postoperative rehabilitation schedule in old adult patients is due to their decreased physical strength and cognitive function.
The KSS clinical and functional scores improved significantly for patients 80 years of age and older from preoperative mean scores of 33 and 27 to latest follow-up scores of 87 and 51 respectively (p < 0.05). No knees have required revision subsequently. The VAS improved significantly from preoperative mean scores of 8 to latest follow-up scores of 0 (p < 0.05). At least a follow-up time of 3 years after surgery, all but one patient had substantial relief of pain after TKA. The data were similar to studies which were reported by several authors showing that TKA provides predictable relief of pain and improvement in function in the octogenarian populations[17].
However, the ROM did not improve significantly from preoperative mean 89°to latest follow-up 93°(p > 0.05). They benefited mainly from pain relief and function improvement after TKA, but limited from squatting and other large knee flexion activities. To sit in a chair without using one’s hands requires 93° knee flexion on average, and tying one’s shoes while seated requires 106° flexion on average. Most elderly patients said that their knee function after TKA was adequate for daily life and could ensure basic self-care[18].
The proportion of patients who did not use crutches at last follow-up was 52%. Other patients with crutch or wheelchair after TKA mainly complained of lower limb weakness. The exercise of muscle strength of the lower limbs of elderly patients over 80 years was very important for postoperative recovery, and it was also difficult among Chinese population to keep at home[19].
The proportion of patients’ satisfaction rate was 94%, and the 50 points or more rate of “Forgotten Joint” Scale (FJS) was 85%. This result indicated that “relieving the pain and keeping basic functions” the main purpose of TKA was achieved[20], [21].
Our study has several limitations. The primary limitation is that the study lacked adequate power to compare the results of TKAs with two knees in one stage with two knees in two stages. The other limitation is that several prostheses were used during the study, and comparison of results based on the implant used also would be prone to inadequate power. Third, the minimum 3-year follow-up period is still short, which may have impacted the results. We will continue to follow up the patients for 5 to 15 years, as the patients are currently aged above 80.