Biportal and Uniportal Endoscopy Compared in Trial
The trial investigates how biportal and uniportal endoscopic approaches differ in postoperative disability, imaging results, and recovery metrics for lumbar spinal stenosis.
A prospective cohort study is comparing two minimally invasive surgical techniques—unilateral biportal endoscopy (UBE) and uniportal endoscopy (UE)—for the treatment of lumbar spinal stenosis (LSS), a degenerative condition that commonly causes back and leg pain in older adults. The study includes 120 patients, with 60 assigned to each group, and will follow them for 12 months postoperatively to assess functional outcomes, pain levels, radiographic changes, and complications. The primary outcome is the Oswestry Disability Index (ODI), measured at 12 months. A minimal clinically important difference of 12.8 and a standard deviation of 19.6 were used to calculate the required sample size. The study has a power of 90%, a significance level of .05, and accounts for a 10% loss to follow-up. Secondary outcomes include clinical, radiologic, and laboratory parameters. Pain intensity is assessed using the visual analogue scale (VAS) for the lower back and legs. Functional status is evaluated with the Japanese Orthopaedic Association (JOA) score and the 36-Item Short Form Health Survey (SF-36). Surgical effectiveness is rated using the modified MacNab criteria. Radiographic assessments include the dural sac enlargement ratio—calculated as (postoperative area / preoperative area − 1) × 100%—the decompression range based on the resected lamina and facet joint area, and the preservation rate of the facet joint measured on MRI or CT. Laboratory outcomes include postoperative serum creatine kinase (CK) and erythrocyte sedimentation rate (ESR). Eligible patients are aged 50 to 80 years, diagnosed with single- or double-level LSS, and have had at least 3 months of conservative treatment fail. Exclusion criteria include previous lumbar surgery, instability beyond grade I spondylolisthesis, scoliosis greater than 20 degrees, and other spinal disorders such as infection or tumor. Surgical technique was selected through shared decision-making between the patient and surgeon. UBE procedures are performed under general anesthesia using two portals—one for visualization and one for instruments. UE procedures use a single working channel under local anesthesia with sedation. According to lead author Haining Tan, MD, from the Department of Orthopaedics at Beijing Friendship Hospital, “This is one of the few single-center, prospective, non-randomised cohort trials to compare the efficacy and safety of UBE and UE decompression in patients with LSS. The clinical and radiological results will be evaluated comprehensively and in detail during the prospective follow-up up to 1 year after surgery, which is also a favourable supplement to the existing studies in terms of study design and content.” All surgeries are performed by experienced spine surgeons at a single center. Postoperative evaluations are conducted by blinded assessors at 3 days, 2 weeks, and 1, 3, 6, and 12 months. Data are collected using electronic case report forms and independently verified to ensure accuracy. The study was approved by an institutional review board and registered in both international and Chinese clinical trial registries. Findings from this trial aim to provide stronger evidence for selecting between UBE and UE techniques in patients with lumbar spinal stenosis, addressing gaps in current research due to the lack of prospective comparative data. The authors reported no conflicts of interest. Source: BMJ Open
