A nomogram prediction model for lumbar disc herniation recurrence after percutaneous endoscopic lumbar discectomy: a multicenter retrospective study.

BACKGROUND CONTEXT: Recurrent lumbar disc herniation (rLDH) is a common postoperative complication after percutaneous endoscopic lumbar discectomy (PELD), with recurrence rates reported between 5% and 21%. Identifying patients at risk remains a critical clinical need, yet few predictive models exist to guide prevention.

PURPOSE: To develop and externally validate a predictive nomogram model for rLDH following PELD, based on preoperative clinical and imaging parameters.

STUDY DESIGN/

SETTING

A multicenter retrospective cohort study using data from 4 hospitals in China.

PATIENT SAMPLE: A total of 3,610 patients who underwent PELD for L4-L5 or L5-S1 disc herniation were included. The training cohort comprised 2,436 patients from 2 centers between January 2012 and December 2021. The external validation cohort included 1,174 patients from 2 additional centers between January 2012 and December 2021.

OUTCOME MEASURES: The primary outcome was the occurrence of rLDH, defined as symptom recurrence at the operated level after a pain-free interval of at least 2 weeks. Predictive accuracy was assessed using area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis.

METHODS

Independent risk factors for rLDH were identified using multivariate logistic regression after variable selection with the Least Absolute Shrinkage and Selection Operator algorithm. A nomogram was constructed based on the final model. Internal validation was performed using bootstrap resampling. External validation was conducted in a separate patient cohort. This study received no external funding. The authors declare that no financial support was obtained for the research, authorship, and/or publication of this article.

RESULTS

Younger age (OR per year increase 0.972, 95% CI 0.956-0.988), Modic type I (OR 1.650, 95% CI 1.075-2.607) and type II (OR 5.755, 95% CI 3.702-9.202) changes, smaller multifidus cross-sectional area (OR 0.900, 95% CI 0.864-0.937), excessive lumbar lordosis (OR 1.033, 95% CI 1.019-1.049), and larger facet joint orientation (OR 1.047, 95% CI 1.031-1.064) were independent predictors of rLDH. The nomogram demonstrated good discriminative ability in both the training cohort (AUC=0.755) and validation cohort (AUC=0.831), with satisfactory calibration and clinical utility supported by decision curve analysis.

CONCLUSIONS

We developed and externally validated a nomogram model to predict rLDH after PELD using readily available preoperative variables. This tool may assist spine surgeons in early risk stratification and tailored postoperative management; however, as this was a retrospective study, prospective validation and inclusion of intraoperative variables are still needed.