Uniportal Full-endoscopic Foraminotomy for Lumbar Foraminal Stenosis: Clinical Characteristics and Functional Outcomes

Objective: Uniportal full-endoscopic foraminotomy offers a promising alternative to conventional surgical methods for individuals afflicted by lumbar foraminal stenosis. This study aims to evaluate the efficacy and clinical outcomes of uniportal full-endoscopic foraminotomy in patients diagnosed with lumbar foraminal stenosis. Methods: A comprehensive retrospective analysis was conducted on individuals who underwent full-endoscopic foraminotomy in our medical center, between January 2018 and December 2019. The investigation encompassed the demographic data of patients and key clinical metrics such as the visual analogue scale of leg (VAS-L) and back pain (VAS-B), Oswestry disability index (ODI) scores, the Short Form-36 Health Survey physical component summary (SF-36 PCS) and the mental component summary (SF-36 MCS), as well as modified MacNab grades, were systematically assessed and compared. Furthermore, radiological parameters: Coronal Cobb angle (CCA), Intervertebral angle changes (IAC), Disc height index (DHI), the foraminal cross-sectional area (FCSA) and the FCSA enlargement ratio were also compared. A variety of statistical analyses including Student t-test, chi-square tests, Fisher's exact tests, Pearson's and Spearman's correlation analyses, and Interclass Correlation Coefficients (ICCs) were employed. Results: 64 patients, including 34 males and 30 females were enrolled. The mean follow-up period extended to 22.66 +/- 7.05 months. Distribution by affected segments revealed 26.6% at L4-5, 67.1% at L5-S1 level, and 6.25% at both L4-L5 and L5-S1 levels. At the final follow-up, VAS-L decreased from 7.26 +/- 1.19 to 1.37 +/- 1.25, while VAS-B decreased from 6.95 +/- 0.54 to 1.62 +/- 1.13 (p < 0.001). ODI score also demonstrated a substantial decrease from 74.73 +/- 8.68 to 23.27 +/- 8.71 (p < 0.001). Both SF-36 PCS and SF-36 MCS scores improved significantly (p < 0.001). Modified MacNab criteria revealed 58 excellent-good patients (90.7%), and 6 fair-poor patients (9.3%). No significant differences were founded in the CCA (p = 0.1065), IAC (p = 0.5544), and DHI (p = 0.1348) between pre-operation and the final follow-up. However, the FCSA significantly increased from 73.41 +/- 11.75 to 173.40 +/- 18.62 mm2 (p < 0.001), and the enlargement ratio was 142.9% +/- 49.58%. Notably, the final follow-up FCSA and the FCSA enlargement ratio were found to be larger in the excellent and good group compared to the fair and poor group, according to the modified MacNab criteria. Conclusion: The utilization of uniportal full-endoscopic foraminotomy has demonstrated its safety and efficacy in addressing lumbar foraminal stenosis. The clinical success of this procedure appears to be closely associated with the radiological decompression of the intervertebral foramen area. Importantly, the application of this technology does not seem to compromise the overall stability of the lumbar region.