The first week matters: App-based PROM trajectories and follow-up retention after endoscopic lumbar surgery

Full-endoscopic spine surgery (FESS) is increasingly utilized for the treatment of degenerative lumbar spinal disorders, with the aim of minimizing tissue disruption and facilitating recovery. Concurrently, postoperative follow-up is shifting toward digital platforms, enabling high-frequency collection of patient-reported outcome measures (PROMs). The characteristics of postoperative recovery trajectories and the determinants of long-term follow-up adherence in this setting remain incompletely defined.

Do postoperative PROM trajectories and follow-up retention differ between full-endoscopic lumbar discectomy and decompression, and does early postoperative engagement predict long-term follow-up compliance?

This prospective multicenter cohort study included adult patients undergoing lumbar full-endoscopic discectomy or decompression for degenerative pathology between 2018 and 2025. Postoperative PROMs were collected using a smartphone-based application on a daily basis during the first postoperative week and at predefined intervals up to six months. Outcomes included visual analog scale (VAS) scores for back and leg pain and the Oswestry Disability Index (ODI). Longitudinal PROM trajectories were analyzed, and follow-up retention was assessed using Kaplan-Meier analysis and Cox proportional hazards regression in a baseline-engaged cohort. Early postoperative PROM adherence was evaluated as a predictor of long-term retention.

A total of 478 patients were analyzed (279 discectomy, 199 decompression). Both cohorts demonstrated significant and sustained reductions in back and leg pain beginning on postoperative day one and persisting through six months (all p < 0.001). Functional recovery, as measured by ODI, followed a delayed course and exhibited a transient early postoperative increase in the decompression cohort. Six-month complete PROM datasets were available in 31.6% of discectomy patients and 48.4% of decompression patients. Follow-up retention differed significantly between procedures, with decompression associated with a lower hazard of dropout (adjusted HR 0.60, 95% CI 0.50-0.72). Higher PROM completion during the first postoperative week was independently associated with long-term follow-up compliance.

High-frequency app-based PROM assessment allows detailed evaluation of early and mid-term recovery following FESS. However, long-term outcome interpretation is constrained by follow-up attrition, which varies by procedure type.

Early postoperative engagement appears to be a key determinant of durable follow-up and represents a potential target for improving longitudinal outcome assessment.