The study was approved in 2022 by the Ethics Committee of the Fourth Affiliated Hospital of Soochow University (approval No. 220083) and was conducted in accordance with the Declaration of Helsinki. Because the retrospective analysis used previously collected and de-identified clinical and follow-up data without introducing any additional intervention or data-collection procedure, the Ethics Committee formally waived the requirement for additional written informed consent for the retrospective research analysis. Before entering the smart nursing program, each participant had provided written clinical consent for the use of the wearable rehabilitation terminal, remote monitoring, transmission, and clinical storage of health data, and video-based rehabilitation guidance.
Study design
This was a single-center retrospective comparative cohort study in which receipt of smart nursing–enabled individualized rehabilitation was treated as the exposure and conventional continuing rehabilitation as the comparator. Allocation was nonrandomized and was not determined solely by the treatment period. Following routine discharge counseling, the patient and treating team jointly selected the rehabilitation approach based on the patient's preference, willingness, and ability to use remote monitoring; availability of caregiver assistance; clinical suitability; and availability of the wearable rehabilitation terminal. Patients who selected and were able to undertake terminal-supported rehabilitation entered the smart nursing group, whereas patients who selected routine follow-up or for whom the terminal was unavailable received conventional continuing rehabilitation. To limit selection bias, all consecutively identified eligible records were assessed, identical eligibility criteria were applied to both groups, and both groups received the same surgical and in-hospital perioperative care; nevertheless, residual confounding related to motivation, digital literacy, caregiver support, treatment preference, and other unmeasured factors could not be eliminated. Statistical analysis was performed by retrospectively retrieving perioperative medical records, complete records of continuing rehabilitation interventions, and standardized follow-up data collected 12 months after surgery. No prospective intervention was introduced during the study period. The original clinical diagnosis, treatment, and nursing pathways were not altered in any way. All data used for analysis were obtained from the hospital's fully archived clinical diagnosis and treatment database, nursing management database, and dedicated follow-up database, ensuring the dataset was traceable and verifiable.
Study population
The electronic medical record system was queried for patients who underwent single-level or two-level posterior lumbar interbody fusion between January 1, 2024, and January 31, 2025, and follow-up information was collected through January 31, 2026. The archived screening log began with records returned by the prespecified date- and procedure-restricted database query; the total number of lumbar operations performed before those database filters was applied was not retained and should not be interpreted as an eligibility-screening denominator. The query returned 117 records for formal eligibility assessment; all 117 met the eligibility criteria, and no record was excluded. The final analytical cohort, therefore, comprised 54 patients in the smart nursing group and 63 in the control group. All 117 patients had complete baseline and 12-month outcome data; no participants were lost from the analytical cohort, and no outcome values were imputed. Participant selection and follow-up are summarized in Figure 1.
Inclusion criteria
1) Elderly patients aged ≥60 years; 2) patients diagnosed with lumbar degenerative disease on the basis of imaging findings combined with clinical symptoms, including lumbar spinal stenosis, lumbar disc herniation, and lumbar spondylolisthesis, who underwent single-level or two-level posterior lumbar interbody fusion (PLIF/TLIF); 3) surgery performed between January 1, 2024, and January 31, 2025; 4) complete preoperative baseline assessment data and complete 12-month postoperative follow-up data, with no missing core data; 5) clear consciousness after surgery, ability to cooperate with rehabilitation evaluation and follow-up, and complete, traceable medical records.
Exclusion criteria
1) Cases complicated by severe failure of major organs such as the heart, liver, or kidneys, malignant tumors, or severe cognitive impairment (Mini-Mental State Examination, MMSE score <24), making rehabilitation follow-up impossible; 2) a history of lumbar surgery, spinal deformity, spinal infection, or spinal fracture; 3) cases complicated by peripheral neuropathy, lower-limb motor dysfunction, or severe osteoporosis that could interfere with evaluation of rehabilitation outcomes; 4) missing core data during the 12-month postoperative follow-up period, making complete statistical analysis impossible; 5) transfer to another hospital during postoperative recovery or loss to follow-up.
Rehabilitation exposure and clinical procedures
During the in-hospital perioperative period, patients in both groups received the same routine diagnosis, treatment, and nursing care provided by the Department of Orthopedics at the hospital. These measures included postoperative vital-sign monitoring, incision care, position management, dietary guidance, and instruction in early bedside rehabilitation. At discharge, all patients were given the hospital's standardized printed manual for postoperative lumbar rehabilitation. Within 24 h before surgery, a standardized baseline assessment, surgery-related health education, and rehabilitation pretraining were completed to ensure that patients had mastered key movements such as log rolling, ankle pump exercise, and diaphragmatic breathing. After the patients returned to the ward, continuous ECG monitoring was maintained for 24 h, a three-tier pain management strategy was implemented, and early bedside rehabilitation training was started once vital signs were stable. From postoperative day 1 to day 7, stepwise rehabilitation training was carried out, along with incision care and prevention of complications such as thrombosis and pulmonary infection. Before discharge, a comprehensive rehabilitation assessment was completed; the Home-Based Rehabilitation Guidance Manual After Lumbar Surgery was uniformly distributed; practical evaluation of core rehabilitation movements was conducted; and discharge education was completed, with signatures from both patients and caregivers confirming completion of the instruction. Conventional continuing rehabilitation. After discharge, patients in the control group followed the fixed home rehabilitation program contained in the hospital's printed manual and received routine telephone follow-up and outpatient review over 12 months. No wearable rehabilitation terminal, automated alert, or remote dynamic adjustment of the rehabilitation plan was used. Pain, medication use, wound condition, neurological symptoms, exercise performance, and complications were reviewed during routine contacts and documented in the electronic medical record or follow-up database. The archived protocol did not maintain a uniform contact-frequency schedule for every patient; therefore, follow-up contacts reflected routine departmental practice and clinically indicated review, as summarized in Table 1. Smart nursing–enabled individualized rehabilitation. In addition to the routine follow-up, outpatient review, and printed rehabilitation manual provided to the control group, patients in the smart nursing group received a 12-month program incorporating four stages of exercise progression, clinician-reviewed monitoring via a wearable rehabilitation terminal, predefined alert-triggered contact, and periodic adjustments to the rehabilitation plan. The objectives and principal progression rules of the four stages are summarized below, whereas the complete exercise dose, progression criteria, safety criteria, and monitoring actions are presented in Table 2.
The program was delivered through a wearable rehabilitation terminal (see Table of Materials) connected to the hospital's smart nursing management platform. The terminal generated processed movement-trajectory, exercise-duration, training-frequency, and surface electromyography (sEMG)-derived monitoring indices, which were transmitted to the platform at a 1 Hz update rate, equivalent to one processed update per second. The 1-Hz value refers only to the platform update rate and does not represent the raw inertial measurement unit or sEMG sampling frequency. The archived clinical records did not contain raw IMU or sEMG waveforms; raw sampling rates; filtering, preprocessing, feature-extraction, or downsampling procedures; the allocation of processing between the wearable terminal and server; firmware or algorithm-version identifiers; proprietary implementation details; formal accuracy or test–retest reliability estimates; the medical-device registration number; or a quantitative data-loss rate. These technical characteristics could not, therefore, be independently reconstructed, and the terminal was treated solely as a clinician-reviewed monitoring and alert-support tool rather than as a validated diagnostic or quantitative sEMG instrument. Stage-specific movement templates were constructed from standardized exercise demonstrations performed under the supervision of the rehabilitation therapist, and each patient's first correctly completed supervised repetitions were stored as the individual reference for subsequent percentage-deviation calculations. Before initial use, the terminal underwent its built-in self-check and zero-reference procedure, after which the responsible nurse or rehabilitation therapist confirmed sensor placement, signal stability, and successful data transmission. Because the proprietary processing procedures were unavailable, these reference-based indices were used only to support clinician review and were not interpreted as validated physiological measurements. The sensing module was placed over intact paraspinal skin lateral to the surgical incision and outside the wound-dressing margin and was worn only during prescribed rehabilitation sessions after clinical clearance. Patients and caregivers were instructed to inspect the skin before and after each session; the terminal was removed during bathing, wound care, imaging examinations, or any episode of erythema, pain, blistering, or other irritation. When skin irritation occurred, use was suspended, the responsible nurse assessed the affected area by telephone, photograph, or video, and rehabilitation guidance continued without the terminal until the skin condition had resolved. Patients unable to tolerate the terminal were instructed to continue the clinically appropriate exercise program under telephone or video supervision, although the number and duration of episodes of intolerance were not retained in the analytical dataset. Processed data were transmitted by Bluetooth to a patient-side mobile gateway and then through the hospital-managed network; temporarily interrupted transmissions were synchronized after reconnection, whereas intervals that could not be recovered were recorded by the platform as device off-time. Aggregate wear time, unrecovered off-time, technical-failure counts, and reconnection duration were not exported to the archived analytical dataset.
Before discharge, all patients received a multidimensional baseline assessment covering age, surgical procedure, comorbidities, pain severity (Numeric Rating Scale, NRS), paraspinal muscle strength (Manual Muscle Test, MMT), and cognitive function, based on which a four-stage stepwise individualized rehabilitation program was developed, with clear training parameters, intensity progression rules, and individualized pain management strategies. The rehabilitation program comprised an adaptation phase during postoperative weeks 1–4, a core-activation phase during weeks 5–8, a functional-recovery phase during weeks 9–12, and a maintenance phase during weeks 13–52. Exercise intensity and progression were determined jointly by pain status, wound condition, therapist-confirmed movement quality, functional performance, and completion of the prescribed program. The exercise type, dose, progression criteria, safety or stopping criteria, and monitoring actions for each stage are provided in Table 2.
A predefined rule-based three-level alert system was used; no machine-learning or artificial-intelligence model was involved. Red alerts required clinical review within 1 h and were triggered by an NRS score ≥7 at rest, an NRS score ≥9 during activity, a persistent NRS score ≥4 for more than 24 h, or an sEMG amplitude deviation ≥20% in two consecutive 1-s monitoring windows. Yellow alerts required corrective guidance within 48 h and were triggered by an NRS score of 4–6 at rest, an NRS score of 6–8 during activity, movement-trajectory deviation ≥15% for three consecutive repetitions, or completion of <80% of the prescribed training plan for three consecutive days. Blue alerts were used for routine education and outpatient-review reminders and were closed within 72 h. Movement-trajectory deviation was defined as the platform-calculated mean absolute percentage difference between a completed exercise trajectory and the stage-specific reference template. The sEMG criterion was defined as the percentage deviation of the root-mean-square amplitude from the patient's supervised reference performance for the same exercise. According to the archived clinical protocol, the 15% movement-deviation and 20% sEMG-deviation values were selected before program implementation through internal discussion among the two orthopedic specialist nurses, one rehabilitation therapist, and one attending orthopedic surgeon who delivered the rehabilitation program. The protocol did not use a pilot dataset, a Delphi procedure, a formal consensus rating, an inter-rater agreement assessment, calibration against expert-annotated movements, or validation against subsequent clinical outcomes, and the quantitative rationale for selecting 15% and 20% beyond the internal clinical consensus was not retained. These thresholds should therefore be interpreted only as exploratory operational triggers for clinician review, rather than as validated clinical, diagnostic, or safety cutoffs. The intervention team reviewed all platform-uploaded data daily, with one-to-one video guidance provided for nonstandard movements, incomplete training, or abnormal fluctuations in pain. Comprehensive rehabilitation reassessment was performed every 4 weeks, with the program dynamically adjusted based on training adherence, pain improvement, and muscle strength recovery; updated plans were sent to the patient's terminal with one-to-one explanation from the responsible nurse. Monthly online rehabilitation health education, full-process outpatient review, multistep reminders, and automatic encrypted archiving of all supervision, alert-handling, and program-adjustment records were implemented throughout the 12-month intervention period.
Data sources, extraction, and follow-up schedule
Perioperative characteristics were extracted from the electronic medical record system; rehabilitation exposure and intervention records were extracted from the nursing management database; and 12-month outcomes were extracted from the dedicated follow-up database. Two assessment time points were analyzed: T0, defined as the assessment completed within 3 days before surgery, and T1, defined as the final assessment completed 12 months after surgery. Data extraction was performed using a standardized form, and group assignments and outcome values were checked against the original records before analysis.
Platform access was restricted to named rehabilitation team members via individually authenticated accounts and role-based authorization. Clinical data were stored within the hospital-managed information environment, and only de-identified variables were exported for research analysis. The platform audit log recorded account access, alert handling, and rehabilitation plan modifications; however, the frequency of audit log reviews and audit findings was not analyzed as study outcomes. The archived study records did not contain the specific cryptographic algorithm, encryption strength, key-generation or key-rotation procedure, or other key-management documentation, and these details could not be independently reported. Accordingly, the manuscript describes only the security controls that could be verified from the clinical workflow and does not claim cryptographic reproducibility or independent security validation.
Indicators related to chronic pain control
Numeric Rating Scale (NRS) scores10 under resting and active conditions at T0 and T1 were extracted. The scale ranges from 0 to 10, where 0 represents no pain, and 10 represents the worst pain imaginable; higher scores indicate more severe pain. The incidence of chronic postsurgical pain (CPSP) at T1 was also recorded. CPSP was defined as pain located in the lumbar surgical area that persisted for ≥3 months after surgery, had an NRS score ≥3, and could not be better explained by another condition11. In addition, the mean monthly frequency of oral analgesic use during the 12-month postoperative follow-up period and the Pain Self-Efficacy Questionnaire (PSEQ) score12 at T1 were collected. The PSEQ contains 10 items, each scored from 0 to 6, giving a total score of 0–60. Higher scores indicate better pain self-management efficacy. The Cronbach's α coefficient of this scale is 0.92, indicating good reliability and validity.
Indicators of paraspinal muscle strength recovery and core functional restoration
The cross-sectional area of the erector spinae muscle at T0 and T1 was extracted from measurements obtained with a lumbar color Doppler ultrasound system (see Table of Materials). During measurement, patients were placed in the prone position with the paraspinal muscles relaxed. A transverse scan was performed at the L4/5 intervertebral level, the cross-sectional areas of the bilateral erector spinae muscles were measured, and the mean of both sides was calculated in cm2. The maximum isometric strength of the paraspinal muscles was measured using an isokinetic muscle testing system (see Table of Materials). At T1, the rates of achieving the target muscle strength and of completing core stability rehabilitation movements were also recorded in both groups. Muscle strength attainment was assessed using the Manual Muscle Test (MMT)13, which grades strength from 0 to 5; a grade of ≥4 was defined as attainment. The quality of movement completion was evaluated by rehabilitation therapists and included three core training movements: bridging, prone trunk extension, and plank. According to the hospital's standardized movement criteria, performance was classified as qualified or unqualified, and the overall qualification rate was then calculated. In addition, Berg Balance Scale (BBS) scores14 at T0 and T1 were extracted. This scale contains 14 items, each scored from 0 to 4, with a total score of 0–56. Higher scores indicate better balance function and a lower risk of falling. The Cronbach's α coefficient is 0.96, showing good reliability and validity.
Core outcome measures of lumbar function and long-term prognosis
Japanese Orthopedic Association Scores (JOA)15, the Oswestry Disability Index (ODI)16, and the Modified Barthel Index (MBI)17 at T0 and T1 were extracted to comprehensively evaluate lumbar function and activities of daily living. The JOA scale covers four dimensions, namely subjective symptoms, clinical signs, limitation of daily activities, and bladder function, with a total score of 0–29; higher scores indicate better lumbar function. The ODI covers 10 dimensions, including pain intensity, self-care, lifting, and walking. Each item is scored from 0 to 5, with a total score of 0–50; after conversion to a percentage, higher scores indicate more severe lumbar dysfunction. The MBI includes 10 daily activity items, such as feeding, grooming, dressing, toileting, and walking, with a total score ranging from 0 to 100; higher scores reflect better daily functioning and greater self-care ability. At T1, bone graft fusion was assessed according to the Bridwell fusion grading system based on lumbar CT findings obtained with an electronic computed tomography scanner (see Table of Materials). Grades I–II were defined as successful bone graft fusion, and the lumbar fusion rate was calculated in both groups. The cumulative incidence of falls during the 12-month postoperative follow-up period was also recorded.
Indicators of health-related quality of life and psychological status
The assessment results of the 36-Item Short Form Health Survey (SF-36)18 at T0 and T1 were extracted. This scale includes two dimensions, the Physical Component Summary (PCS) and Mental Component Summary (MCS), both converted to a 0–100 scale; higher scores indicate better health status in the corresponding domain. Psychological status was evaluated using the Generalized Anxiety Disorder-7 (GAD-7)19 and the Patient Health Questionnaire-9 (PHQ-9)20.
Indicators of rehabilitation-related adverse events and complications
The cumulative incidence of poor incision healing/infection, nerve root irritation/lower-limb numbness, adjacent-segment degeneration, deep venous thrombosis of the lower limbs, and unplanned readmission during the 12-month postoperative follow-up period was recorded in both groups.
Indicators related to medical resource utilization and rehabilitation costs
Resource use was evaluated descriptively from healthcare-service and patient/caregiver perspectives over the 12-month follow-up period; this analysis was not designed as a formal cost-effectiveness evaluation. Outpatient and emergency visits were extracted from the medical records and follow-up databases. Total rehabilitation-related cost was defined as the cumulative amount recorded in the hospital billing and follow-up systems for rehabilitation services, rehabilitation-related outpatient or emergency care, and use of the wearable rehabilitation platform, and was expressed in nominal Chinese yuan. Home caregiving burden was recorded as the cumulative number of months during which regular assistance was required and was not converted into a monetary value. Because the observation horizon was 12 months, neither discounting nor inflation adjustment was applied.
Statistical analysis
All analyses were performed using statistical software (see Table of Materials). The primary outcome was the between-group difference in the change in activity-related NRS score from baseline to 12 months. Continuous outcomes measured at both T0 and T1 were analyzed using generalized estimating equations with a Gaussian distribution, identity link, exchangeable working correlation structure, and robust sandwich standard errors. Each model included rehabilitation group, assessment time, and the group-by-time interaction; the interaction coefficient represented the between-group difference in change from baseline to 12 months. A covariate-adjusted sensitivity analysis was additionally performed for each repeated continuous outcome by modeling the individual change score using linear regression with HC3 robust standard errors and including the baseline value of the corresponding outcome, age, sex, body mass index, primary diagnosis, surgical procedure, and number of fused levels as covariates. The adjusted estimates are reported in Supplementary Table 1. Continuous outcomes assessed only at T1 were compared using Welch's independent-samples t-test. CPSP, muscle-strength attainment, qualified movement completion, bone graft fusion, and falls were compared using Pearson's χ2 test, whereas the four low-frequency complication outcomes were analyzed using Fisher's exact test. Continuous effects are reported as mean differences or group-by-time interaction estimates with 95% confidence intervals, and categorical effects are reported as risk differences with 95% confidence intervals. Shapiro–Wilk tests and Q–Q plots indicated departures from normality for most bounded-scale and change-score variables; robust standard errors and Welch's test were therefore used to reduce reliance on the assumptions of equal variance and normality. The primary outcome was tested at a two-sided α level of 0.05 and was not included in the multiplicity adjustment. The Benjamini–Hochberg procedure was applied across the 26 secondary outcomes to control the false discovery rate at 5%, and both unadjusted P values and adjusted q values are reported. All 117 patients had complete baseline and 12-month outcome data, and no imputation was performed. Because the study included all eligible archived records, no a priori sample size calculation was undertaken; a descriptive sensitivity analysis indicated that group sizes of 54 and 63 provided 80% power to detect a standardized mean difference of approximately 0.52 at a two-sided α level of 0.05.