“Slipped vertebra” sounds as though something were on the move that urgently needed holding in place. Usually the opposite is true: a vertebra that has slid a little way forwards over the years is as a rule stable and often causes no symptoms at all. This page explains which forms there are, how we tell whether the slippage really is the cause of your symptoms, and when a fusion comes up for discussion at all.
What matters is not how far the vertebra has shifted, but whether it still moves, whether it constricts nerves — and whether that fits your symptoms. Only once all three questions are answered with yes is an operation discussed.
What is it?
In spondylolisthesis (slipped vertebra), one vertebral body is displaced forwards relative to the one below it. Two forms account for the greater part of cases, and they have little in common. In degenerative spondylolisthesis the small vertebral joints and the disc give way through wear, so that the vertebra slowly travels forwards; the level affected is usually L4/5, predominantly in women from middle age onwards. Because the spinal canal becomes narrower in the process, this form is often combined with spinal stenosis. In isthmic spondylolisthesis there is a gap in the vertebral arch (spondylolysis), which usually arises in childhood or adolescence; the vertebra thereby loses its bony locking at the back and can slip, almost always at the lowest level, L5/S1.
The extent of the displacement is graded according to Meyerding: grade I means a displacement of up to a quarter of the depth of the vertebral body, grade II up to a half, grade III up to three quarters, grade IV beyond that; when the vertebra tips off completely, this is called spondyloptosis. The great majority of findings are grade I or II. The grade describes the picture, not the symptoms — a grade I can constrict nerves, a grade II can stay silent for decades.
What symptoms occur?
Typical is a deep-seated low back pain that increases on standing, walking and bending backwards and eases when sitting or bending forwards. Some describe a feeling as though the back might “give way” or not hold when straightening up. If leg symptoms are added, they depend on the form: in degenerative slippage, the accompanying narrowing of the spinal canal produces heavy, tingling or tired legs after a certain walking distance, which recover when sitting. In isthmic slippage, the L5 nerve root is often constricted in its exit opening — then the pain runs like sciatica down the outer side of the leg to the top of the foot, often with tingling or numbness.
Just as common is the other case: the slippage is discovered during an examination carried out for another reason and has nothing to do with the symptoms. In adolescents with a recent arch defect, a load-dependent low back pain is usually to the fore, often after sports involving hyperextension.
Causes
In degenerative slippage the sequence is usually the same: the disc loses height, the small vertebral joints are thereby loaded more heavily, wear down and change their orientation, the ligaments loosen — and the vertebra gives way forwards. Why women are affected considerably more often has not been conclusively clarified; hormonal influences on the strength of the ligaments are suspected.
The arch defect in isthmic slippage is as a rule a fatigue fracture during the growing years, encouraged by repeated bending backwards — gymnastics, javelin, butterfly swimming, martial arts — and by a family predisposition. Once growth is complete, the slippage only rarely progresses. Less common are congenital malformations of the vertebral joints, a slippage after an accident, after an earlier spinal operation or in bone diseases.
How is it diagnosed?
At the examination we feel for a step over the spinous processes, test mobility, the walking pattern and nerve function — strength of the foot and toe lifters, reflexes, sensation, stretch signs. The most important image is then a lateral X-ray taken standing: lying down, and therefore in MRI as well, a slipped vertebra can partly return to its place, so that the extent is underestimated. Images in forward and backward bending show whether the vertebra moves between the two positions. Only then do we speak of instability — a fixed slipped vertebra is not one.
MRI shows whether nerve roots or the spinal canal are constricted; CT depicts an arch defect most reliably. What the terms in your report mean is explained on the page Understanding your MRI report. It always holds that the picture must match the symptoms. A slipped vertebra at L4/5 does not explain pain that follows the area supplied by S1.
Warning signs
A spondylolisthesis is almost never an emergency. The exceptions are numbness in the area of the buttocks and the perineum, a new problem with passing urine or opening the bowels, and paralysis that increases within hours or days — then the examination belongs in an emergency department on the same day. Everything else on the page Warning signs.
Conservative treatment
For most people with a spondylolisthesis, treatment without an operation is the right one — and it begins with putting things in perspective: the vertebra will not “slip out”, and movement does not harm it. Bed rest and taking it easy make the situation worse.
- Physiotherapy and your own training — strengthening the deep trunk and back muscles, which actively stabilise the motion segment; stretching the hip flexors and the hamstrings; avoiding repeated hyperextension for as long as it triggers pain.
- Painkillers — anti-inflammatory medicines for a limited time at the lowest effective dose, so that movement remains possible. For nerve pain, medicines that act on nerve excitability.
- Targeted injection at the nerve root (PRT) — if a constricted root is causing the leg pain, an anti-inflammatory medicine can be injected directly at the root under image guidance. This eases pain for a few weeks; a lasting effect is not established. We provide this treatment at our practice.
- Brace — a supporting corset can relieve acute pain for a short time, but it is not a permanent solution, because it weakens the muscles. In adolescents with a recent arch defect, a break from sport, with a brace where appropriate, can give the fracture time to heal.
- Multimodal pain therapy — for symptoms lasting months, a combined treatment of exercise, pain medicine and psychological support.
When an operation is considered
An urgent operation is performed only for cauda equina syndrome or a rapidly increasing paralysis. A planned operation is considered if leg pain or a restricted walking distance remain despite consistent treatment over several months, the imaging finding matches, and you want the procedure. Back pain alone is only rarely a reason; its outcome after an operation is less predictable than that of leg pain.
The real question is then: is it enough to relieve the pressure on the nerves, or must the segment additionally be fused? Large studies have given different answers to this. An American study found, after two years, a small advantage of the additional fusion for physical quality of life and fewer follow-up operations; a Swedish and a Norwegian study found no meaningful difference compared with decompression alone. A fusion is therefore not added automatically, but is considered when functional images show movement of the slipped vertebra, when the slippage is of a higher grade or is increasing, when so much bone has to be removed for the decompression that the segment would otherwise lose its hold, in isthmic slippage with narrowing of the nerve exit opening, and in pronounced, mechanically triggered back pain.
Surgical options
Two building blocks come into question, singly or combined: the microsurgical decompression of the constricted nerves and the fusion of the slipping segment with screws and rods (spondylodesis). We offer both procedures. The aim of the fusion is not to pull the vertebra fully back to its old place — that is usually neither necessary nor sensible — but to end the movement in the segment, so that the bone lets it grow together permanently.
- ProcedureUnder general anaesthetic and lying face down, the constricted nerves are exposed under the microscope through an incision in the middle of the back. For the fusion, screws are placed in the two vertebrae involved and connected with rods; whether a spacer with bone material is additionally inserted into the disc space depends on the findings. The position of the implants is checked with X-ray during the procedure. The operation takes several hours, the hospital stay usually a few days.
- RisksAs with any operation, infection, bleeding, thrombosis and the risks of anaesthesia. Specific to this procedure: an injury to the membrane around the nerves with leakage of spinal fluid; rarely damage to a nerve root with sensory disturbance or weakness; a malposition or later loosening of screws; a failure of the bone to fuse, with persisting symptoms; and the need for a further procedure. In the long term the adjacent segment can be loaded more heavily and wear faster. A pre-existing numbness can remain; the back pain does not always disappear completely. Which of these is to the fore in your situation, we discuss before the procedure.
- AftercareGetting up on the day after the operation; walking is encouraged. For a few weeks no heavy lifting, no twisting under load and no deep bending; after that physiotherapy and later your own training. The bony fusion takes months and is checked with X-rays. A follow-up rehabilitation is often sensible. How long you are unfit for work depends on your occupation.
With suitable findings, screws can also be placed through small incisions at the side; whether that has advantages in an individual case depends on the findings. In a recent arch defect in young people, a direct screw fixation of the defect may come into consideration instead of a fusion.
Alternatives
The most important alternative is supported waiting, with training, pain treatment, an injection if needed and checks of strength, sensation and walking distance. If an operation is due, decompression alone without fusion is a genuine alternative, which we weigh up openly with you. If you have been advised elsewhere to have a fusion, you can obtain a second opinion from us.
What to expect
A degenerative slippage progresses, if at all, slowly over years, and the symptoms run in waves. An isthmic slippage only rarely changes once growth is complete. What you can do yourself: train the trunk muscles for the long term, break up periods of sitting, keep an eye on your weight, avoid sports with repeated hyperextension for as long as they trigger pain. Watch your walking distance and the strength in your feet — if either of them gets worse, get in touch. After a fusion, X-ray checks are part of it until the segment has fused.
Frequently asked questions
Can the vertebra slip out completely?
No. Ligaments, muscles and the shape of the vertebral joints hold the vertebra even when it is displaced. A sudden slipping during an everyday movement does not occur.
Does a spondylolisthesis have to be fused?
In most cases not. A fusion is considered if symptoms remain for months, the segment is demonstrably unstable, or the nerves cannot be relieved in any other way. Many slipped vertebrae go a whole lifetime without an operation.
What does “Meyerding grade I” mean in my report?
That the vertebra is displaced by less than a quarter of its depth — the mildest and most common form. The grade says nothing about whether and how severely you have symptoms.
May I do sport with a spondylolisthesis?
Yes, movement is part of the treatment. Walking, cycling, swimming and strength training with clean technique are usually well tolerated. Sports with repeated bending backwards or hard impacts you should only do if they do not trigger pain.
What should I bring to my first appointment?
Any existing X-ray, CT and MRI images on CD together with the reports, especially images taken standing. Everything else is on the page Your first appointment.