The biportal endoscopic approach was first introduced in 1996 by Dr. De Antoni [1,2]. However, biportal endoscopy did not advance significantly in the field of spinal surgery and was not commercially or clinically developed. Biportal endoscopy was introduced to South Korea and has made remarkable advancements since the 2010s [2,3]. Similar to conventional spine surgery, biportal endoscopic approaches were performed in the prone position, using a radiofrequency probe and a drill, and a surgical toolkit set was developed [3]. It further evolved in Korea under the name unilateral biportal endoscopy (UBE). UBE is the abbreviation for unilateral biportal endoscopy, but it is now commonly used as a representative term for biportal endoscopy [2]. Recently, UBE has been established as a globally practiced surgical technique [4-6].

Currently, UBE is being performed not only in South Korea but also globally, experiencing rapid advancement [5,6]. It is used not only for simple decompressive surgery but also for interbody fusion [7]. Moreover, UBE is applied in the surgical treatment of not only lumbar conditions but also cervical and thoracic spine diseases [8-10]. In the lumbar region, UBE was first attempted for discectomy, and later, laminectomy was successfully performed using UBE to treat lumbar central or lateral recess stenosis [3]. If lumbar discectomy is considered the first generation of UBE, subsequent procedures such as lumbar laminotomy, paraspinal approach, and contralateral approach can be regarded as the second generation. More recently, lumbar interbody fusion has been performed using the UBE approach, marking it as the third generation of lumbar UBE surgery (Table 1) [4,11,12].

UBE surgery in the cervical and thoracic regions has been recently developed but is continuously advancing [9,13]. UBE is primarily utilized for surgeries involving posterior approaches in the cervical and thoracic spine. The UBE approach was first successfully applied in posterior cervical foraminotomy (PCF) [10]. Currently, it has also been successfully performed in decompressive cervical laminectomy for cervical spondylotic myelopathy [9]. Moreover, UBE is now being used in cervical laminoplasty and posterior cervical instrumentation, such as cervical lateral mass screw fixation and pedicle screw fixation [14,15]. If PCF is considered the first generation of cervical UBE, then cervical laminectomy can be regarded as the second generation, and cervical instrumentation as the third generation (Table 1) [14,15].

In the thoracic region, UBE is used for procedures ranging from thoracic discectomy to thoracic interbody fusion [13]. After thoracic discectomy was attempted, UBE was utilized in the surgical treatment of thoracic stenosis and thoracic ossification of the ligamentum flavum (OLF). Thoracic laminectomy using UBE is now one of the most commonly performed surgeries. Thoracic laminectomy and OLF removal can be considered the second generation of thoracic UBE, while thoracic interbody fusion can be regarded as the third generation (Table 1) [13].

UBE continues to evolve through the efforts of pioneering spinal surgeons and their successors, who are advancing the technique [16]. Even today, various attempts are being made globally, with numerous research papers being published. If a robotic spine surgery system, similar to the da Vinci robot used in other surgical fields, is developed in the future, it is conceivable that UBE could serve as its foundational model. Although some misconceptions and biases about UBE still exist, these will likely be overcome through academic research and the growing experience of surgeons. The biportal endoscopic spine approach, or UBE, is expected to continue its advancement and play a pivotal role in the field of spinal endoscopic surgery.