The lateral (modified paramedian) approach versus the conventional paramedian approach for spinal anesthesia in patients aged ≥80 years undergoing hip surgery: a retrospective cohort study

Background Spinal anesthesia in patients aged ≥80 years is often challenging due to severe degenerative changes of the lumbar spine. The conventional paramedian approach may still encounter difficulties. This study aimed to compare the efficacy and safety of a lateral (modified paramedian) approach with the conventional paramedian approach for spinal anesthesia in patients aged ≥80 years undergoing hip surgery. Methods This retrospective cohort study was conducted at Jinling Hospital between January 2022 and December 2025. In this retrospective cohort study, 144 patients aged ≥80 years who underwent hip surgery under spinal anesthesia were included. 65 patients (MP group) received the lateral approach, and 79 patients (CP group) received the conventional paramedian approach. A 1:1 propensity score matching (PSM) was performed to balance age, sex, BMI, ASA physical status, and spinal degeneration grade. The primary outcome was the first-attempt success rate. Secondary outcomes included anesthesia-to-surgery time, needle repositioning required, repositioning rate, incidence of complications, and postoperative hospital stay. Results After PSM, 65 patients remained in each group. Baseline characteristics were well-balanced (all P > 0.05). The first-attempt success rate was higher in the lateral group than in the conventional paramedian group (56.9% vs. 50.8%), but the difference was not statistically significant (OR 1.27, 95% CI 0.62–2.61, P = 0.617). The lateral approach significantly reduced anesthesia-to-surgery time (mean difference –6.40 min, 95% CI –11.32 to –1.48, P = 0.012) and the incidence of postoperative back pain (12.3% vs. 27.7%, OR 0.37, 95% CI 0.15–0.89, P = 0.032). Conclusions The lateral (modified paramedian) approach was associated with significantly shorter anesthesia-to-surgery time and a lower incidence of postoperative back pain. Although the first-attempt success rate was numerically higher with the lateral approach, the difference did not reach statistical significance, and the current data do not establish its superiority. The lateral approach may serve as a valuable alternative for this vulnerable population, though further prospective evaluation is warranted. As a retrospective single-center study, residual confounding and selection bias cannot be fully excluded.