What's the difference between open surgery, minimally invasive surgery, and endoscopic (UBE) surgery?

The main difference between these approaches is not what they fix, but how the surgeon reaches the part of the spine that needs to be treated. The actual goal of the operation — removing a herniated fragment, decompressing a compressed nerve, or stabilizing a segment — is often the same regardless of approach. What differs is the size of the opening, the amount of muscle and soft tissue disturbed along the way, and how the surgeon sees the surgical field. Understanding the three approaches as points along a spectrum of access, rather than as competing products, is the most useful way to think about them.

Open surgery is the traditional approach. The surgeon makes an incision and gently moves the muscle aside to view the spine directly, with the naked eye or with the aid of a microscope. The direct, wide view this provides remains valuable, and for certain situations — complex deformity, revision surgery in scarred tissue, or cases requiring extensive reconstruction — it is still the most appropriate choice. Its trade-off is that reaching the spine this way disturbs more of the surrounding muscle and soft tissue than the alternatives.

Minimally invasive surgery (MIS) was developed to reduce that approach-related tissue disturbance. In its conventional form, the surgeon works through one or more small incisions, typically using a tubular retractor that spreads the muscle fibers apart rather than cutting across them, and views the surgical field through a microscope or loupes. Across the published evidence, this kind of tubular MIS approach to lumbar fusion has generally been associated with less blood loss, shorter hospital stays, and lower rates of certain complications, while producing long-term clinical outcomes broadly comparable to open surgery.^{1 2} In other words, the main documented advantages of tubular MIS tend to lie in the early recovery period rather than in the final result, which over time tends to converge with that of open surgery.

UBE — unilateral biportal endoscopy — represents a different paradigm again. Although it belongs to the broad minimally invasive category, it is not simply a smaller version of tubular microscopic surgery; it relies on a fundamentally different way of seeing. Instead of looking down a tube through a microscope, the surgeon makes two small independent portals — one for an endoscope that delivers a high-magnification, well-illuminated, and continuously irrigated view directly onto a screen, and one as a free working channel for the instruments. Because the viewing portal and the working portal move independently, the surgeon retains a wide, flexible range of motion while seeing the anatomy at a magnification and from angles that a tube-based microscopic view cannot easily reach. This endoscopic approach is one of the most actively studied and rapidly developing areas in minimally invasive spine surgery today, and studies of UBE for conditions such as lumbar disc herniation and stenosis have reported meaningful relief of back and leg pain and improvement in function.³

The most important point for a patient to understand is that a smaller incision is not automatically a better operation. The approach is not the first decision; it follows from the diagnosis. The type, location, and extent of the problem — together with the patient's anatomy, prior surgeries, and general health — determine which approaches are suitable, and sometimes the most appropriate choice for a particular problem is an open one. A useful question in consultation is therefore not "which approach is the most advanced?" but "given my specific condition, which approaches are appropriate, and what are the trade-offs of each in my case?" The right answer is the one matched to the problem, not the one with the smallest scar.