Spinal Stenosis Surgery Without Screws (Minimally Invasive Surgery / UBL)

Spinal stenosis surgery without screws (UBL) is a microsurgical method that relieves the nerves on both sides of the canal through a one-sided approach while preserving the spine’s posterior supporting structures. Suitable patients do not need screws or fusion; the hospital stay is generally one night.

What Is Spinal Stenosis Surgery Without Screws? (UBL Technique)

Screws are not required in every patient undergoing spinal stenosis surgery. In suitable patients, bilateral decompression through a unilateral approach (UBL or ULBD) relieves nerve pressure while largely preserving the posterior supporting structures. Advances in microsurgical technology have enabled us to use this method in recent years. This innovative method works as follows:

• Access Through a Minimal Incision: A much smaller skin incision than in the conventional method is used, with minimal interference with surrounding muscles.
• Bilateral Widening Through One-Sided Access: Only one side of the bony roof at the back of the spine (lamina) is removed.
• Undercutting from Within: High-resolution surgical microscopes allow access to the opposite side, where only the inner (front) surface of the bone is shaved with millimetre precision.

Thus, although the operation appears one-sided from the outside, the nerves on both sides of the canal are relieved through a single approach.

Conventional Laminectomy and the Need for Screws

Open lumbar laminectomy has been the conventional operation widely used worldwide for many years for spinal stenosis. This traditional technique completely removes the bony structures called laminae at the back of the vertebrae, which form the roof of the tunnel. In conventional surgery:

• A substantial amount of bone and the strong ligaments supporting the spine may be sacrificed.
• Extensive removal of bone and ligaments can increase the later risk of vertebral slippage (spondylolisthesis) in some patients.
• If considered necessary in this situation, instrumented spondylolisthesis surgery (fusion surgery) is performed.

The Surgical Procedure

• Anaesthesia: The operation is performed microsurgically under general anaesthesia in a fully equipped operating theatre.
• Tissue-Preserving Approach: The aim is to adequately relieve nerve pressure while protecting the muscles and ligaments that keep the spine stable.
• Hospital Stay and Recovery: The stay is generally one night. Preserving muscle and bone reduces early postoperative lower back pain and facilitates return to daily life.

Success Rates of Screw-Free Spinal Stenosis Surgery

In suitable patients, surgery without screws is as successful as instrumented fusion surgery: at 2- and 5-year follow-up, there was no difference in limitations in daily life or walking distance [1, 3]. Compared with open laminectomy, 84% of patients were satisfied (75% after open surgery), and the reoperation rate was 1.6% (5.8% after open surgery) [4]. In patients with mild spondylolisthesis, however, quality of life was better in the group receiving screws [5]; the decision is therefore individualised.

What Are the Risks?

Blood loss and hospital stay are lower than with open laminectomy, while the risk of tearing the membrane around the nerves (dural tear) is similar [4]. Without screws, there are no screw-loosening or implant problems; new narrowing at the adjacent level is more common in patients undergoing fusion [2]. Nevertheless, this is surgery: dural tear, nerve damage, infection, bleeding and a need for repeat surgery may occur. A dural tear identified during the operation is repaired.

🩺 Physician’s Insight & Clinical Experience

“My goal in surgery is to adequately relieve pressure on the nerves while preserving as much of the spine’s supporting structures as possible. An important advantage of UBL is that the opposite side can also be decompressed through a one-sided approach, allowing sufficient canal widening with more limited bone and muscle dissection. In appropriately selected patients, fusion and screws may not be needed because the supporting structures are largely preserved.”

Frequently Asked Questions

What Is Screw-Free Spinal Stenosis Surgery, and How Is It Performed?

It is a microsurgical operation that widens both sides of the canal by removing the bony roof on one side and undercutting the opposite side from within.

What Is Its Success Rate?

In suitable patients, it is the same as surgery with screws [1, 3]. In comparison with open surgery, 84% of patients were satisfied [4].

Does It Have Risks or Side Effects?

Yes, but they are lower than in open surgery: blood loss and hospital stay are reduced, and dural-tear risk is similar. Because no screws are inserted, risks such as screw loosening do not occur [2, 4].

When Can I Get Up After Surgery?

Our patients can stand and walk approximately 4–6 hours after surgery once the anaesthetic has worn off. Hospital stay is generally one night.

Will My Symptoms Disappear Immediately?

For many patients, yes: leg pain and cramps during walking decrease markedly early on. Numbness and tingling from prolonged compression may take several weeks or months to disappear completely.

Can I Bend After Surgery?

Sudden bending, twisting and heavy lifting should be avoided during the first 4–6 weeks of tissue healing. However, squatting by bending the knees or moving as demonstrated by the doctor is possible.

When Can I Return to Work?

Our patients with desk jobs generally return within 10–15 days; for physically demanding work, this is 4–6 weeks. Gentle walks early in recovery make returning to work easier.

Is This Method Suitable for Every Patient with Spinal Stenosis?

No, UBL or screw-free decompression is not automatically suitable for everyone. Suitability depends on the anatomical type and level of narrowing, spinal stability, existing spondylolisthesis/deformity, neurological findings and the extent of decompression required.

How Much Does It Cost?

As treatment costs vary according to the patient and hospital conditions, a definite fee can only be determined after examination and review of imaging.

Which Specialist Performs Screw-Free Spinal Stenosis Surgery in Istanbul?

One of the physicians performing this operation in Istanbul is M. Levent Deniz, MD, a specialist in brain, nerve and spine surgery.

References

1. Försth P, Ólafsson G, Carlsson T, et al. A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis. N Engl J Med. 2016;374(15):1413-1423. PMID: 27074066. PubMed
2. Karlsson T, Försth P, Skorpil M, et al. Decompression alone or decompression with fusion for lumbar spinal stenosis: a randomized clinical trial with two-year MRI follow-up. Bone Joint J. 2022;104-B(12):1343-1351. PMID: 36453045. PubMed
3. Austevoll IM, Hermansen E, Fagerland MW, et al. Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis. N Engl J Med. 2021;385(6):526-538. PMID: 34347953. PubMed
4. Phan K, Mobbs RJ. Minimally Invasive Versus Open Laminectomy for Lumbar Stenosis: A Systematic Review and Meta-Analysis. Spine (Phila Pa 1976). 2016;41(2):E91-E100. PMID: 26555839. PubMed
5. Ghogawala Z, Dziura J, Butler WE, et al. Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis. N Engl J Med. 2016;374(15):1424-1434. PMID: 27074067. PubMed

• 👨‍⚕️ Author and medical reviewer of this content: M. Levent Deniz, MD – Brain, Nerve and Spine Surgeon
• ⚠️ Medical Disclaimer: This page is for information only; consult your doctor for diagnosis and treatment.