Arthroscopic-assisted uni-portal spine surgery via modified interlaminar approach combined with annular suturing for L5/S1 disc herniation: a case report and technical note.

Background: Lumbar disc herniation (LDH) is a common clinical spinal disorder, with the L5/S1 segment being a frequently affected site due to its unique anatomical and biomechanical characteristics. Conventional minimally invasive spinal endoscopic techniques, such as percutaneous transforaminal endoscopic discectomy (PTED), percutaneous endoscopic interlaminar discectomy (PEID), and unilateral biportal endoscopy (UBE), have inherent limitations in treating L5/S1 LDH. These include difficulty bypassing the high iliac crest (for PTED), a steep learning curve (for PEID), and potential impairment of spinal stability (for UBE). To address these challenges, this study applied Arthroscopic-assisted uni-portal spine surgery (AUSS) via a modified interlaminar approach combined with 4-0 absorbable suture annular repair for L5/S1 LDH, reporting its short-term clinical outcomes and detailing key technical points. Case presentation: A 45-year-old male patient presented with a 1-year history of low back pain, which worsened over 1 month with persistent right lower limb radicular pain, unresponsive to conservative treatment. Preoperative lumbar MRI and CT confirmed L5/S1 disc herniation, with T2-weighted MRI showing low signal intensity of the herniated disc and axial CT demonstrating direct compression of the right S1 nerve root by the herniated nucleus pulposus. The patient underwent the modified procedure: during surgery, a portion of the ligamentum flavum was excised to expose the herniated nucleus pulposus, while the remainder was retracted and preserved. After complete removal of the herniated nucleus pulposus, full-thickness annular suturing was performed using 4-0 absorbable sutures, with knot tying performed extracanalicularly and pushed into place using a dedicated knot pusher. At 1, 3, and 12 months postoperatively, the incision healed well without complications such as infection, nerve injury, or cerebrospinal fluid leakage. Imaging re-evaluation showed no recurrence of L5/S1 disc herniation and a smooth posterior annular margin. The patient experienced significant relief of low back and leg pain, resuming normal daily activities within 1 month postoperatively. The visual analogue scale (VAS) score decreased from 7 preoperatively to 1, the Japanese Orthopaedic Association (JOA) score reached 25, and the Oswestry Disability Index (ODI) decreased from 68% preoperatively to 12%. Conclusion: Arthroscopic-assisted uni-portal spine surgery via the modified interlaminar approach combined with annular suturing is a safe, feasible, and effective treatment for L5/S1 LDH. Its core advantages include bypassing anatomical barriers such as the high iliac crest, maximizing the preservation of spinal osseous and ligamentous structures, ease of operation, high surgical efficiency, and a low short-term recurrence rate. This procedure is a targeted optimization of the traditional interlaminar approach, providing a valuable treatment option for L5/S1 LDH, especially in cases where conventional endoscopic techniques are limited. However, the results of this single-case study cannot be generalized to long-term efficacy, and large-sample, multi-center follow-up studies are needed for further validation.