Early functional training is not superior to routine rehabilitation in improving walking distance and multifidus atrophy after lumbar fusion: a randomized controlled trial with 6-month follow-up.

PURPOSE: To investigate the effects of early functional training within a 12-week rehabilitation program on walking distance and lumbar multifidus atrophy following lumbar fusion surgery.

METHODS

A total of 52 patients who underwent lumbar fusion surgery were randomly assigned to either the early functional training group (n = 26) or the routine rehabilitation group (n = 26). The early functional training group (FT group) began a progressive functional training program within the first 12 weeks post-surgery, while the routine rehabilitation group (RH group) started the same training program 12 weeks after surgery. The primary outcome was the walking distance, measured as the 6-minute walk distance (6MWD) at the 3-month, and 6-month follow-up. Secondary outcomes included the cross-sectional area (CSA) of the multifidus muscles, the Visual Analogue Scale (VAS) score, the Oswestry Disability Index (ODI) score, the Short Form 36 Health Survey (SF-36) subscales, including the Physical Component Summary (PCS) and Mental Component Summary (MCS), and the incidence of adverse events. The primary aim was evaluated using a 2-way mixed-model analysis of covariance (ANCOVA), with treatment group as the between-subjects factor and time as the within-subjects factor, after adjusting for baseline measures.

RESULTS

Among the total patients, 38 (73.1%) left with at least one follow-up result, and 29 (55.8%) completed all treatment sessions and obtained an MRI assessment. The mixed-model ANCOVA revealed a significant group-by-time interaction for the 6MWD (F = 6.214, p = 0.003). Patients in the FT group demonstrated superior 6MWD compared to the GH group at 3 months (95% CI: 32.51 to 101.88, p < 0.001). No significant differences were found between the two groups at the 6-month follow-up (95% CI: -15.34 to 54.03, p = 0.271). Regarding secondary outcomes, no significant group-by-time effects were found for ODI (F = 1.221, p = 0.299), PCS (F = 0.166, p = 0.847), or MCS (F = 0.282, p = 0.755). No significant differences were found in the CSA of multifidus muscles between the groups. Nine patients (17.3%) experienced adverse events.

CONCLUSION

Early functional training after lumbar fusion was not superior to routine rehabilitation in improving walking distance, multifidus atrophy, pain, physical function, and quality of life during the 6-month follow-up. Trial registration number (TRN): ChiCTR2300068296.