Preoperative step count as a predictor of early postoperative mobility and patient-reported outcomes following lumbar spine surgery.

OBJECTIVES: Objective activity monitoring may provide scalable, real-world functional data in lumbar spine surgery patients. We evaluated whether preoperative daily step count predicts early postoperative ambulation and patient-reported outcomes (PROs). MATERIALS AND METHODS: We performed a retrospective cohort study of adults undergoing elective lumbar decompression, discectomy, or fusion with remote monitoring of daily step counts (preoperative days 7-1 and postoperative days [PODs] 1-28) and longitudinal PROs (Patient-Reported Outcomes Measurement Information System [PROMIS] - Pain/Physical/Mental and Oswestry Disability Index [ODI] at baseline, 6 weeks, 12 weeks, 6 months, and 1 year). Patients were stratified by mean preoperative step count into low activity (<2500 steps/day) versus normal activity (≥2500 steps/day). Between-group comparisons used the Chi-square tests for categorical variables and independent t-tests for continuous variables (P < 0.05). RESULTS: Forty-seven patients were included (mean age: 51.8 ± 13.7 years; body mass index: 29.85 ± 5.00), including 21 (44.7%) low-activity and 26 (55.3%) normal-activity patients. Preoperative steps were lower in the low-activity group (1354 ± 639 vs. 5148 ± 2399; P < 0.001). Postoperative step counts did not differ during POD 1-7 (717 ± 857 vs. 1342 ± 1468; P = 0.091) but were higher in the normal-activity group during POD 8-14 (1515 ± 2048 vs. 2863 ± 2288; P = 0.044) and cumulatively through POD 28 (POD 1-28: 1360 ± 1584 vs. 2784 ± 1978; P = 0.010). By POD 8-14, 53.8% of normal-activity patients achieved ≥2500 steps/day versus 14.3% of low-activity patients (P = 0.005). Normal-activity patients reported lower PROMIS Pain at 6 weeks (2.9 ± 2.4 vs. 4.8 ± 2.1; P = 0.011) and 12 weeks (2.4 ± 2.2 vs. 4.0 ± 2.5; P = 0.029) and lower ODI at 12 weeks (17.4 ± 14.7 vs. 29.5 ± 17.7; P = 0.018). CONCLUSIONS: Preoperative step count stratifies early postoperative mobility and short-term pain/disability trajectories after lumbar spine surgery. Objective activity monitoring may support perioperative risk stratification and targeted prehabilitation.