Clinical value of a novel V-shaped annular suture under unilateral biportal endoscopy: a retrospective comparative study with the traditional I-shaped suture

Abstract

Background: Annular tears after lumbar discectomy can lead to reherniation and poor long-term outcomes. Traditional I-shaped sutures often fail to achieve sufficient closure strength at the annular defect. This study aimed to evaluate the clinical efficacy and safety of a novel V-shaped annular suture technique compared with the traditional I-shaped suture during unilateral biportal endoscopic lumbar discectomy.

Methods: A retrospective study was conducted on 50 patients who underwent single-level lumbar discectomy with annular repair between January 2022 and June 2024. Patients were divided into two groups based on the suture method: the I-shaped suture group (n = 27) and the V-shaped suture group (n = 23). Operative parameters (suture time, intraoperative blood loss), postoperative pain (visual analogue scale, VAS), functional recovery (Oswestry Disability Index, ODI), disc degeneration (Pfirrmann grade), complication rate, and recurrence rate were compared between groups. Statistical analyses were performed using independent-sample t tests or chi-square tests as appropriate.

Results: The mean follow-up duration was 14.5 ± 3.2 months. By the final follow-up, the recurrence rate was 11.1% (3/27) in the I-shaped group, while no recurrence was observed in the V-shaped group during follow-up. Both groups showed significant improvement in postoperative VAS and ODI scores compared with preoperative values (P < 0.05), but no significant intergroup difference was found (P > 0.05). Pfirrmann grades significantly improved postoperatively in both groups (P < 0.05), with no difference between groups (P > 0.05). According to the modified MacNab criteria, the excellent-to-good rate was higher in the V-shaped group (78.3%) than in the I-shaped group (70.4%), though not statistically significant (P = 0.199). No severe complications were observed in either group.

Conclusions: The V-shaped annular suture provides improved closure stability and may reduce the risk of postoperative recurrence compared with the traditional I-shaped suture. Although technically more demanding, this technique is safe and effective, showing promising clinical applicability for lumbar annular repair.

Keywords: Annular repair; Clinical efficacy; Endoscopic discectomy; I-shaped suture; Lumbar disc herniation; Recurrence; Unilateral biportal endoscopy; V-shaped suture.