My leg numbness keeps getting worse-when does Seoul One Hospital consider endoscopic spine surgery
A neurological exam checking for muscle weakness and reduced walking distance — not just numbness — is key to deciding on endoscopic spine surgery.
I am Dr. Soo-Taek Lim, board-certified orthopedic surgeon and Director of Seoul One Hospital. Among patients who come in after being diagnosed with a lumbar disc herniation, when someone tells me their leg numbness persists even at rest or is gradually spreading, I start by reviewing the neurological exam again.
Key Answer
What matters more than the numbness itself worsening is whether strength is weakening in the ankle or toes, and whether walking distance is gradually shortening.
If these two signs appear together despite adequate non-surgical (conservative) treatment, I actively discuss minimally invasive spine treatment options, including endoscopic spine surgery. I don't rush to surgery for numbness alone, but when muscle weakness and reduced walking distance occur together, it is better to decide before nerve damage becomes permanent.
Questions This Article Answers
- If leg numbness gets worse, do I necessarily need surgery?
- What symptoms warrant considering endoscopic spine surgery?
- What's the difference between uniportal and biportal endoscopic spine surgery?
- How long should I try conservative treatment before deciding?
- If I have paralysis symptoms, is medication alone enough?
Why Leg Numbness Occurs with Lumbar Disc Herniation, and When It's a Warning Sign
Leg numbness occurs when a herniated disc fragment presses on a nerve root. Sciatica is a common symptom, with an annual incidence of 1-5% and a lifetime prevalence of up to 43% PMC4464797.
Interestingly, the more severely a disc herniates, the higher the rate of spontaneous resorption. By type, spontaneous resorption rates have been reported at 13.3% for simple bulging, 52.5% for protrusion, 70.4% for extrusion, and up to 93.0% for sequestrated fragments PMID 37486886.
The overall spontaneous resorption rate is also not low, at 66.66% (95% CI 51-69%) PMID 28072796.
That's why I compare, at intervals of several weeks, whether the nerve compression is resolving naturally or whether muscle strength is also declining, rather than focusing on the numbness alone. Patients who can wait for the disc to be resorbed naturally and patients whose nerves may suffer irreversible damage in the meantime follow completely different paths.
Analysis of 16 studies reporting higher spontaneous resorption rates for more severe hern… · 출처: PMID 37486886
That's why at Seoul One Hospital, during the initial visit, we first pinpoint the segment causing the numbness using MRI and neurological exams, and record numerically whether the condition is one that can be observed for a natural course.
How We Choose Between Uniportal and Biportal Endoscopic Spine Surgery
Endoscopic spine surgery is indicated for patients with severe radiating leg pain, weakness in ankle or toe muscle strength, a gradually shortening walking distance, or those for whom general anesthesia or a prior surgery poses a significant burden.
I don't consider either uniportal (UED) or biportal (BESS) to be unconditionally superior. Disc location, extent of stenosis, age, and overall health status determine which approach I choose — this has been my principle over more than 25 years of performing minimally invasive spine surgery.
Uniportal is suitable when the treatment area is small and only the disc has herniated. With a single incision, there is less pain and muscle damage, but the field of view and instrument angle are limited.
Biportal is chosen when stenosis is severe and extensive decompression is needed. Although there are two incision sites, moving the endoscope and instruments separately allows for a wider field of view.
Both approaches are performed through incisions under 1cm, and saline irrigation during surgery lowers the infection rate. In the endoscopic foraminal decompression photos published by our hospital, you can see a nerve that had been pale from compression regain its color after decompression.
| Category | Uniportal (UED) | Biportal (BESS) |
|---|---|---|
| Suitable for | Simple disc herniation | Severe stenosis requiring extensive decompression |
| Incision sites | 1 | 2 |
| Advantages | Less wound/muscle damage | Wide field of view, flexible approach |
| Disadvantages | Limited view/instrument angle | Two incision sites |
That's why Seoul One Hospital is equipped to perform both approaches, determining the right method for each patient after confirming disc location and extent of stenosis on imaging.
I once had a patient who brought in an MRI showing what appeared to be simultaneous degeneration at two or three lumbar levels. Looking at the images alone, multiple segments seemed problematic, but the actual numbness and muscle weakness were traced to only one segment. Because the spine is a structure of multiple connected joints, there is a risk of misdiagnosis and treating the wrong segment, so I always cross-check symptoms against imaging and precisely decompress only the single causative segment.
How to Decide Between Conservative Treatment and Surgery
Whether conservative treatment is sufficient depends on how much improvement occurs after how many sessions.
For patients who receive 2-3 sessions of conservative treatment such as injections and improve by 60-80%, with that improvement lasting more than 2-3 months, conservative treatment is sufficient. Conversely, if pain does not decrease by more than half, or if pain returns within 1-2 weeks after an injection requiring repeated treatment, the patient falls into a cycle of relying on medication and injections.
I recall counseling two patients representing these two patterns. One patient's symptoms improved significantly after 2-3 nerve block procedures, allowing a return to daily life, while another patient's pain recurred every 1-2 weeks despite the same repeated treatment. For the latter, I recommend moving up to a higher level of treatment — a procedure or surgery.
A case requiring even more careful attention is a patient who has paralysis symptoms but wants medication only. Some patients come in saying their legs or arms are weak, their grip strength is gone, they stagger when walking, or their legs give out on stairs — yet they ask to "just be prescribed medication." When an MRI shows severe nerve compression, leaving this untreated can result in permanent disability, so in these cases I make sure to thoroughly explain why medication alone should not be the final approach.
After surgery, pain is typically the first thing to markedly improve, while sensory and motor paralysis gradually returns over 2-3 months, and in some cases over a year. Once nerve compression is relieved, pain improvement typically comes first in the general course of recovery.
That's why at Seoul One Hospital, we manage pain with patient-controlled analgesia (PCA) while adjusting the pace of rehabilitation to each individual patient's recovery pattern.
The general order in which pain, sensation, and motor function recover after surgery
Limitations and Precautions
Endoscopic spine surgery is not immediately applicable to every patient with a lumbar disc herniation. I recommend checking the following items yourself.
- Does the leg numbness persist even at rest, or does it only appear and disappear while walking?
- Do you feel that strength in your ankle or toes has decreased compared to before?
- Is the distance you can walk before needing to stop and rest gradually getting shorter?
- Have you experienced more than 60% improvement with conservative treatment (injections/medication)?
- Is the symptom limited to one leg, or has it spread to both?
The following warning signs require immediate medical attention: new low back pain in a patient with a history of cancer, unexplained weight loss, pain that persists even at rest, pain accompanied by fever, or pain in an immunocompromised state — in these cases, ruling out infection or another condition takes priority U.S. National Library of Medicine.
There are also cases where endoscopic spine surgery is not appropriate. Recurrent disc herniation is generally defined as a new herniation at the same site after pain had improved for at least 6 months following the initial surgery; when this recurrence pattern or spinal instability is present, disc removal alone is insufficient, and fusion surgery should also be considered Korea University Medical Center.
Because the recurrence rate and the reoperation rate after discectomy are not the same concept, it is important to explain the possibility of recurrence accurately, without exaggeration, during the preoperative consultation PMC10878111.
When warning signs are identified, we prioritize deciding whether to combine fusion surgery with endoscopic spine surgery, or first proceed with tests to rule out infection or tumor, rather than relying on endoscopic surgery alone.
Seoul One Hospital's Approach to Care
The two questions I'm asked most often by patients visiting for lumbar disc herniation are, "Can this be done without admission?" and "Do I have to get tested again?"
We perform MRI, X-ray, blood tests, urinalysis, ECG, and ultrasound all together as preoperative testing, so patients don't need to visit other hospitals. Disc removal/decompression via endoscopic spine surgery takes about 1 hour, followed by about 30 minutes of recovery room observation, with an average hospital stay of 1-2 weeks.
Surgery is performed using a German Carl Zeiss surgical microscope and a C-arm capable of real-time fluoroscopic imaging; microscopic discectomy is performed through a 1-2cm incision at the center of the lower back to remove the herniated disc and thickened ligament.
At the conservative treatment stage, we also offer options such as radiofrequency nucleoplasty (about 30 minutes) and neuroplasty (about 30 minutes). I don't insist on either uniportal or biportal endoscopic spine surgery alone — I decide the approach by jointly considering disc location, extent of stenosis, age, and overall health status.
Outpatient hours are weekdays from 9 a.m. to 6 p.m. and Saturdays from 9 a.m. to 1 p.m., with lunch break from 1 p.m. to 2 p.m. and closed on Sundays and public holidays. We also regularly hold spine and joint health lectures at senior welfare centers in Gangseo-gu, Seoul and Yangcheon-gu, Seoul, and I recently gave a lecture on lumbar conditions at the Yeonji Senior Welfare Center.
That's why Seoul One Hospital is designed so that testing, surgery, hospitalization, and rehabilitation proceed seamlessly in one place, reducing the burden of additional travel even for patients near Hwagok Station (Seoul Subway Line 5).
Frequently Asked Questions
How long does endoscopic spine surgery take?
For disc removal or decompression, the surgery itself takes about 1 hour, followed by about 30 minutes of rest in the recovery room. We generally advise an average total hospital stay of 1-2 weeks.
Why isn't surgery immediately recommended for numbness alone?
Because, depending on the type of disc herniation, spontaneous resorption rates of over 90% have been reported in some cases PMID 37486886. If there are no additional signs such as muscle weakness or reduced walking distance, there is room to observe the natural course.
Who is better suited to biportal rather than uniportal?
Biportal is considered when the extent of stenosis is wide and extensive decompression is needed. Conversely, if only the disc has herniated locally, uniportal may be sufficient.
I have paralysis symptoms-is medication alone okay?
If weakness in the legs or arms is accompanied by staggering while walking, relying on medication alone carries a risk that nerve damage will become permanent. In such cases, I check the degree of compression with MRI and explain the need for surgical treatment together with the patient.
Key Takeaways
- What matters most for deciding on surgery is not the numbness itself but whether muscle weakness and reduced walking distance are also present.
- Depending on the type, spontaneous disc resorption rates range from 13% to 93%, so not all numbness warrants immediate surgery.
- If 60-80% improvement is sustained after 2-3 sessions of conservative treatment, conservative treatment is sufficient.
- Endoscopic spine surgery is chosen between uniportal and biportal approaches based on disc location and extent of stenosis.
- A history of cancer, unexplained weight loss, and pain accompanied by fever are warning signs requiring immediate evaluation.
About the Medical Team
Dr. Soo-Taek Lim, board-certified orthopedic surgeon, completed his orthopedic residency at Seoul National University Hospital and has researched and treated patients with minimally invasive spine surgery for more than 25 years. He serves as a committee member of the Minimally Invasive Spine Research Society under the Korean Spinal Society. Profile
Seoul One Hospital is located on floors 6-10 of the Dongmyeong M Building, 179 Gangseo-ro, Gangseo-gu, Seoul, a 1-minute walk from Exit 8 of Hwagok Station (Seoul Subway Line 5). Underground parking (basement levels 1-2) is available at the rear of the building. Outpatient hours are weekdays from 9 a.m. to 6 p.m. and Saturdays from 9 a.m. to 1 p.m. If your leg numbness is getting worse, we recommend scheduling a consultation first by phone (1544-5888) or online booking.