Comparison of One-Hole Split Endoscopy and Unilateral Biportal Endoscopy for Far-Lateral Lumbar Disc Herniation at L5/S1: A Short-Term Retrospective Study

The lower back is a complex machine of bone, muscle, and nerve, designed to support the body while allowing for movement. When the soft, jelly-like cushion between two vertebrae slips out of place, it can press against a nerve, causing sharp pain that travels down the leg. This condition, known as a herniated disc, is a common source of suffering. While most slips happen in the middle of the spine, a specific and tricky type occurs on the far side, where the nerve exits the spinal column. This "far-lateral" herniation is particularly difficult to reach because the surrounding bones, including the hip bone and the large transverse processes of the spine, create a narrow, obstructed tunnel. Surgeons have long sought ways to remove this trapped tissue without causing unnecessary damage to the healthy muscles and bones that hold the spine together.

In recent years, the medical community has turned to minimally invasive techniques that use small cameras and instruments to perform these repairs. Two such methods have emerged as leading contenders for this specific, difficult task: one that uses two small entry points and another that uses just one. A team of researchers at a hospital in China set out to compare these two approaches directly. They focused on patients with this far-lateral herniation at the lowest level of the spine, where the L5 vertebra meets the sacrum. By looking back at the records of forty-seven patients treated over a two-year period, the team aimed to see which method offered the better balance of speed, safety, and patient recovery.

The study divided the patients into two groups. One group received treatment using a technique called Unilateral Biportal Endoscopy, or UBE. In this method, the surgeon makes two small cuts in the back. Through one cut, a camera is inserted to provide a wide, clear view of the surgical site. Through the second cut, the surgeon inserts the tools to remove the herniated disc. The other group was treated with a newer method called One-hole Split Endoscopy, or OSE. This approach uses a single, slightly longer incision. Inside this one opening, the surgeon manages both the camera and the tools, often splitting the space to allow them to work side-by-side. Both techniques required the surgeon to carefully remove a small portion of the bone covering the nerve to create enough room to extract the slipped disc material.

When the researchers analyzed the results, they found that both methods were highly effective at relieving pain and restoring function. Patients in both groups reported significant reductions in back and leg pain within days of the surgery, and these improvements continued to grow over the following year. By the end of the study, nearly all patients in both groups were rated as having excellent or good outcomes, with no significant difference between the two groups in how well they felt or how well they could move. This suggests that for this specific type of difficult herniation, both approaches successfully achieve the primary goal of freeing the pinched nerve.

However, the two methods did differ in how the surgery was performed. The group treated with the two-cut UBE method had their operations completed faster, taking an average of about sixty-nine minutes. The single-cut OSE group took longer, averaging about eighty-four minutes. Despite the extra time, the OSE group showed advantages in physical trauma to the body. The single incision in the OSE group was shorter, measuring about 1.6 centimeters, compared to the combined length of the two incisions in the UBE group, which totaled about 2.3 centimeters. Furthermore, the OSE group lost less blood during the procedure, with an average loss of roughly thirty milliliters, compared to about fifty-one milliliters for the UBE group.

The study also looked at the long-term structural health of the spine. Using X-rays and scans, the team measured the alignment of the spine and the size of the openings where nerves exit. They found that neither method caused the spine to become unstable or shift out of place. Both techniques successfully enlarged the space for the nerve, which is crucial for relieving pressure. While the height of the disc space decreased slightly in all patients after surgery—a common occurrence when a disc is treated—the overall stability of the spine remained intact. One minor complication occurred in the OSE group, where a small tear in the protective covering of the spinal cord happened in one patient, but it was repaired immediately during the surgery, and the patient recovered fully without issues.

Ultimately, the research indicates that both techniques are safe and reliable options for treating this challenging form of back pain. The choice between them may come down to the specific needs of the patient and the surgeon's preference. The two-cut method offers speed and a wide view, which can be helpful for navigating complex anatomy, while the single-cut method offers a smaller wound and less blood loss. For a patient facing this difficult surgery, the study provides reassurance that either path leads to a successful recovery, with the spine remaining stable and the pain relieved.