Background:

There are many studies on the impact of frailty on postoperative complications; however, there are few studies focusing on stepwise propensity score matching (PSM) to offset the influence of age.

Methods:

We gathered data for patients undergoing short-level posterior lumbar interbody fusion from January to December 2021. According to the Fried frailty phenotype, we categorized patients into non-frail, pre-frail, and frail groups, then, stepwise PSM for age, sex, American Society of Anesthesiologists (ASA) and fusion levels were performed to keep comparable clinical data between groups. Univariate and multivariate logistic regressions were used to determine the impact of clinical demographics on postoperative complications.

Results:

A total of 559 consecutive patients with complete medical records were enrolled (237 males and 322 females; mean age 72.55 ± 5.86 years). After PSM, we found that pre-frail patients were more vulnerable to develop urinary retention (p = 0.031) and surgical site infections (p = 0.021) than non-frail patients. Longer length of stay (LOS), delayed ambulation and removal of urinary catheter times were observed in pre-frail patients. However, there was a significant difference only in LOS between pre-frail and frail patients. Binary logistic regression revealed that C-reactive protein (CRP) and frail status were independently associated with postoperative complications between non-frail and pre-frail patients, while only CRP was independently correlated with complications between pre-frail and frail patients.

Conclusion:

After PSM, we found higher rates of urinary retention and surgical site infections in pre-frail patients than in non-frail patients. CRP was independently related to postoperative complications, while frail status was only independently associated with postoperative complications between pre-frail and non-frail patients. Pre-frail/frail patients tended to have more severe stress responses than non-frail patients.