Purpose: Frailty is known as a factor that affects the outcomes of long fusion surgery, but its impact on the clinical outcomes of short fusion surgery remains unclear. The purpose of this study is to investigate whether frailty is associated with clinical outcomes in lumbar short fusion surgery.
Methods: This study included patients who underwent lumbar short fusion surgery (1-2 segment fusion) between September 2011 and December 2021. A total of 578 patients were included: 208 males and 370 females, with an average age of 68.6 years. Average follow-up period was 43.3 months. Frailty was assessed using the mFI-5 (0: normal, 1: pre-frail, ≥2: frail). Based on the mFI-5 score, the patients were divided into three groups: normal group, pre-frail group and frail group. Age, gender, number of fusion segments, BMI, pre- and postoperative VAS of low back pain, VAS of leg pain, ODI, RDQ, changes in these scores (ΔVAS for low back pain, ΔVAS for leg pain, ΔODI, ΔRDQ), satisfaction rate, and reoperation rate were compared among the three groups.
Results: There were 141 patients in normal group, 259 in pre-frail group, and 178 in frail group. Age was significantly higher in frail and pre-frail groups than normal group (65.2 years in normal group, 69.7 in pre-frail group, 71.9 in frail group). Gender distribution was not statistically different among the three groups. Preoperative VAS of low back pain (49.1, 54.9, 60.4), ODI (43.3%, 48%, 57.2%), and RDQ (9.7, 12.4, 14.2) were significantly higher in pre-frail and frail groups than normal group. Preoperative VAS of leg pain (64.1, 65.6, 72.7) was significantly higher in frail group than normal group. Postoperative VAS of low back pain (17.6, 22.8, 22.7) and VAS of leg pain (14.5, 18.9, 17.8) showed no significant differences among the three groups. Postoperative ODI (18%, 23.9%, 26.5%) and RDQ (3.9, 5.5, 6.3) remained significantly higher in pre-frail and frail groups than normal group. Changes in VAS of low back pain (31.4, 32.1, 37.8), and leg pain (49.8, 47.4, 54.9) were not statistically different among the three groups. Changes in ODI (25.3%, 24.1%, 30.6%), and RDQ (5.8, 6.9, 7.9) were significantly larger in frail group than normal group. There were no statistical differences in satisfaction rate and reoperation rates among the three groups.
Conclusion: Postoperative ODI and RDQ remained higher in pre-frail and frail groups than normal group, but the improvement of clinical parameters following surgery was equivalent among the three groups. The current results suggest that lumbar short fusion surgery can achieve comparable improvements in patients with frailty as in those without frailty.