Comparison of Clinical and Radiographic Outcomes Between Percutaneous Endoscopic Transforaminal Diskectomy and Unilateral Biportal Endoscopic Diskectomy for the Treatment of L4/5-Level MSU Size-3 Lumbar Disk Herniation: A 2-Year Retrospective Cohort Study

BACKGROUND AND OBJECTIVES: Percutaneous endoscopic transforaminal diskectomy (PETD) and unilateral biportal endoscopic diskectomy (UBED) have demonstrated favorable clinical outcomes in managing lumbar disk herniation (LDH). The surgical treatment of Michigan State University (MSU) Size-3 LDH remains technically challenging. The aim of this study was to compare the clinical and radiographic outcomes of PETD and UBED, specifically in the treatment of L4/5-level MSU Size-3 LDH. METHODS: The study included 138 patients who underwent either PETD (75 cases) or UBED (63 cases). During a follow-up period of at least 2 years, clinical outcomes were evaluated using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), modified MacNab criteria, complication and recurrence rates, serum creatine phosphokinase (CPK) levels, and other surgical data. Radiographic parameters, including intraoperative bone loss, paraspinal muscle-disk ratio, and intervertebral height index, were also monitored. RESULTS: Both VAS scores for low back and leg pain, as well as ODI scores, showed significant decreases in both groups postoperatively. At baseline, 3 months postoperation, and at the final follow-up, VAS and ODI scores showed no statistically significant differences between the 2 groups. Compared with the UBED group, the PETD group showed lower VAS scores for incision pain on the first day and third day after surgery ( P < .001). Although no significant differences were observed in modified MacNab criteria, complication rates, or LDH recurrence, PETD demonstrated advantages in operative time, incision length, intraoperative blood loss, postoperative length of stay, total hospitalization costs, serum CPK levels, and intraoperative bone loss volume ( P < .001). No statistically significant differences were observed in the intervertebral height index or paraspinal muscle-disk ratio. CONCLUSION: Both PETD and UBED can achieve favorable clinical outcomes in the treatment of L4/5-level MSU Size-3 LDH. Compared with UBED, PETD performed under local anesthesia offers superior short-term postoperative incision pain relief, improved perioperative quality of life, and reduced surgical invasiveness.