Facet Joint Cyst (Juxtafacet Cyst): Symptoms, Causes, and Treatment

Prof. Dr. Mehmet Şenoğlu — Brain, Nerve and Spine Surgery

Some of the patients who come to my office arrive with an MRI report in hand and a single question in mind: “Doctor, the report says ‘facet joint cyst.’ What does this mean? Is it something dangerous?”

I understand this unease. A facet cyst — or, by its medical name, a juxtafacet cyst — is not as widely known a condition as a lumbar disc herniation; however, it is one of the overlooked causes of pain radiating into the leg, numbness, and difficulty walking. In fact, it is often mistaken for a “lumbar disc herniation,” because the symptoms are almost identical.

Let me reassure you right away: a facet joint cyst is not cancer, it is not a tumor, and it carries no threat to life. It is a benign, fluid-filled sac. However, because it sits inside the spinal canal and presses on a nerve, it can lead to serious complaints.

In this article, I will explain in clear language what this structure — also called a synovial cyst — is, why it forms, in which situations it requires surgery, and whether or not it resolves on its own.

What Is a Facet Joint Cyst?

Let us briefly recall the anatomy first.

Each vertebra connects to its neighbor at three points: the disc at the front (which acts as a cushion), and two facet joints at the back. Facet joints are true joints, just like the knee or shoulder joint — they have a capsule (a sheath) and contain synovial fluid that lubricates the joint.

A facet joint cyst is a fluid-filled sac that bulges outward from this joint capsule. You can think of it as a balloon swelling outward at a weak point. The problem is this: this bulging is most often directed into the spinal canal, where it presses on the nerve roots passing through.

What Does “Juxtafacet” Mean?

“Juxta” means “next to, adjacent to” in Latin. Juxtafacet cyst — that is, “the cyst next to the facet joint” — is an umbrella term covering all the cysts seen in this region. Why is such a broader term needed? Because two different cyst types can be seen here:

• Synovial cyst: Its inner surface is lined with synovial membrane and it communicates directly with the joint space. It is the more commonly seen type.
• Ganglion cyst: It has no synovial lining and no direct communication with the joint; it is surrounded by a fibrocartilaginous capsule and its contents are of a more gelatinous consistency.

Why does this distinction not matter in practice? Because both are found in the same place, cause the same symptoms, most often cannot be told apart from one another on MRI, and their treatment is the same. A definitive distinction can only be made by pathological examination of the tissue removed at surgery. This is why radiology reports frequently use the phrase “juxtafacet cyst” — this is an honest and accurate description by the radiologist.

So whether your report says “facet cyst,” “synovial cyst,” or “juxtafacet cyst,” it amounts to the same thing clinically.

Why Does a Facet Joint Cyst Form?

The answer to this question is very important, because it directly affects the treatment decision.

A facet cyst is not a structure that forms “out of nowhere.” There is almost always an underlying degeneration (wear) and movement disturbance.

How Does the Process Work?

1. The facet joint wears down. Over the years the joint cartilage thins and degenerative change develops. This is the spinal equivalent of knee osteoarthritis.
2. The joint becomes overloaded and loosens. A worn joint can no longer hold the vertebrae as firmly as before. A small but abnormal mobility — instability — emerges in the segment.
3. The capsule is strained and bulges outward. Repetitive microtrauma and increased intra-articular pressure cause it to herniate at a weak point of the capsule.
4. Fluid accumulates, the cyst grows, and it begins to press on a nerve.

Frequently Accompanying Conditions

• Facet joint degeneration (facet arthrosis) — present in almost every case
• Degenerative spondylolisthesis (vertebral slippage) — accompanies it very frequently; this points to an instability underlying the cyst
• Spinal stenosis (canal narrowing)
• Reduced disc height

I particularly want to emphasize the key concept here: a facet cyst is most often not a “disease” but a “marker.” It is a sign that there is instability in that segment. For this reason, when planning treatment one must look not only at the cyst but at the mechanism producing the cyst. I will return to this point in the surgery section, because it is precisely the basis of the fusion decision.

At Which Level Is It Most Common?

The distribution of facet cysts is not random, and this distribution confirms the mechanism of their formation.

The L4-L5 level is by far in first place. In different surgical series, this level accounts for roughly 63–68% of all lumbar facet cysts. L5-S1 and L3-L4 generally follow.

Why L4-L5? Because L4-L5 is the most mobile segment of the lumbar spine. The place that moves the most is the place that wears the most and is most prone to instability. For the same reason, vertebral slippage is also most frequently seen at this level — this is no coincidence.

Patient profile:

• Generally seen in people around 60 years of age and older (in surgical series the average age is in the sixties)
• Very rare in young people
• Markedly more common in the lumbar region; occurrence in the cervical and thoracic spine is uncommon

Let me add one more note: as imaging technologies have advanced and MRI has been used more widely, the frequency of diagnosis of these cysts has increased markedly. This does not mean “the disease has increased” — it means “we are seeing it better.”

What Are the Symptoms?

The symptoms of a facet cyst depend less on the size of the cyst than on where it sits and which nerve it presses on. Even a small cyst can cause serious complaints if it is at a critical point; conversely, a cyst elsewhere may cause no symptoms at all.

The Most Common Picture: Pain Radiating Into the Leg (Radiculopathy)

This is the reason the great majority of patients present:

• Pain descending from the buttock into the leg, sometimes as far as the foot
• Numbness and tingling in the leg
• Loss of strength in the foot or leg muscles
• Changes in reflexes

Here is the critical point: This picture is almost identical to the one produced by a lumbar disc herniation. Telling the two apart by examination is most often not possible; the MRI makes the distinction. This is why the MRI must be examined carefully in every patient presenting with “sciatica.”

The Second Common Picture: Neurogenic Claudication

This emerges when the cyst narrows the canal, and it is very characteristic:

• Pain, numbness, and a sense of heaviness begin in the legs the more one walks
• It passes on sitting down or bending forward
• Patients generally describe this as “I feel better when I lean on the shopping cart”
• Walking uphill is easier than walking downhill

This symptom can be confused with arterial blockage. The distinction is this: in canal narrowing, bending forward brings relief; in vascular disease, simply stopping is enough.

Other Symptoms

• Low back pain: It frequently accompanies the condition, but is generally not as dominant as the leg pain.
• Sudden onset: If there is bleeding into the cyst, the complaints can begin abruptly within hours. This picture is sometimes confused with an acute disc herniation.

Rare but Urgent: Cauda Equina Syndrome

If a large cyst presses widely on the bundle of nerve roots (the horse’s tail), an emergency picture emerges:

• Disruption of bladder or bowel control
• “Saddle-shaped” loss of sensation in the anal region, the buttocks, and the inner thighs
• Progressive weakness in both legs at once

This picture is a surgical emergency and requires intervention within hours. It is rare, but knowing about it is of vital importance.

How Is It Diagnosed?

MRI: The Gold Standard

A facet cyst is diagnosed primarily with MRI, and its appearance is quite typical:

• A round or oval, well-defined structure immediately adjacent to the facet joint
• Bright (hyperintense) on T2-weighted images — because it is filled with fluid
• Generally posterolateral in position; that is, it pushes the dural sac from behind and to the side
• Accompanying findings: facet joint degenerative change, increased fluid within the joint, disc degeneration

However, not every cyst looks “textbook.” If there has been bleeding into the cyst, if there is calcification, or if the contents have thickened, the signal characteristics change and diagnosis can become difficult. In these situations a contrast-enhanced scan helps: the wall of the cyst takes up contrast while the interior does not — this helps distinguish it from a tumoral mass.

CT

It shows the bony structure far better than MRI. It is valuable in the following situations:

• Seeing the degree of degenerative change in the facet joint
• Demonstrating calcification in the wall of the cyst
• Planning the operation

Dynamic (Flexion-Extension) X-rays

I particularly want to emphasize this examination, because it is frequently skipped and it directly changes the treatment decision.

X-rays are taken with the patient standing, bent forward and leaning backward. The aim is to show whether there is a slippage that emerges with movement (instability) between the vertebrae.

Why is this so important? Because the patient is lying down for the MRI, and in that position the slippage may look “closed.” Standing and with movement, it emerges. The presence of instability is the most critical factor determining whether or not fusion will be added at surgery.

Differential Diagnosis

Similar appearances on MRI can be confused with: a free fragment of a disc herniation (sequestered fragment), an arachnoid cyst, a perineural (Tarlov) cyst, nerve sheath tumors, and rarely infection. Correct distinction requires experienced assessment.

Does a Facet Cyst Resolve on Its Own?

This is the question my patients ask most, and the one that most deserves an honest answer.

The short answer: it can, but this is rare, and waiting in reliance on it is most often not the right course.

Cases in which facet cysts have regressed or disappeared entirely on their own have been reported in the literature. The mechanism is probably the contents of the cyst draining back into the joint space, or the cyst being absorbed over time. However, these are reports at the level of individual case presentations, and they are the exception — not the rule. Indeed, reviews examining the subject specifically state that these cysts “rarely regress without intervention.”

So Why Is It Difficult for It to Resolve on Its Own?

Because the mechanism producing the cyst remains in place. The worn and loosened facet joint continues to strain the capsule with every movement. Even if the cyst empties, it can refill unless the source dries up. This is like emptying water from a leaking bucket.

How Should We Use This Information?

I explain it to my patients like so:

• If your complaints are mild and you have no neurological findings: It is reasonable to try non-surgical treatment for a period. Spontaneous regression is also possible during this process.
• If your complaints are severe or you have loss of strength: Waiting with the thought “maybe it will resolve on its own” is risky. A nerve that stays under compression for a long time may not fully recover even after the compression is relieved.

There are also incidental cysts: cysts found on an MRI taken for another reason that cause no complaints at all. These do not require treatment; they are simply followed up. Let me repeat the sentence I often say to my patients: we treat the patient, not the image.

Non-Surgical Treatment Options

In patients with no neurological deficit, the first step is always non-surgical treatment. However, one needs to know the limits of these options honestly.

Medication

Painkillers and anti-inflammatory medications, and neuropathic pain medications where needed. These do not shrink the cyst; they only manage the symptom and get the patient moving again.

Physical Therapy and Exercise

Strengthening the trunk muscles can reduce the load on the facet joints and ease symptoms. Again, it does not eliminate the cyst, but it contributes to quality of life.

Facet Joint Injection and Cyst Rupture

This is the most specific of the non-surgical options and deserves a detailed explanation.

How is it done? Under fluoroscopic or CT guidance, a fine needle is placed into the facet joint. Fluid is delivered into the joint under control to raise the pressure; the aim is to rupture the wall of the cyst and empty its contents. Then steroid is injected into the joint. In some centers the cyst is aspirated directly (its contents are drawn out).

How well does it work? Here I need to be honest. In the most comprehensive meta-analysis on this subject, data from 544 patients across 29 studies was pooled and the rate of satisfactory outcome was found to be 55.8%; approximately 38.7% of the same group later had to undergo surgery for durable relief. Compared with surgery, the difference becomes even more marked: in a systematic review covering 50 studies and 870 patients, the rate of cyst resolution was found to be 90% with surgical decompression and 58% with percutaneous procedures; the need to repeat the procedure was 29% in the percutaneous group, while it remained below 1% in the surgical group.

Its limits:

• If the cyst wall is thick or calcified, rupture may fail
• The recurrence rate is significant; the procedure may have to be repeated
• Because a thick needle and high pressure are used, there is a risk of complications, however rare
• It is not a suitable option if there is marked loss of strength — in that case losing time becomes risky

I regard this method as a reasonable step in patients whose complaints are moderate, who have no neurological deficit, and who want to avoid surgery. But I tell the patient from the outset: “This is a trial; if it works, excellent — if it does not, we move on to the next step.”

When Is Surgery Needed?

The surgical decision is made by looking not at a single finding but at the picture as a whole.

The Situation Requiring Emergency Surgery

• Cauda equina syndrome: Disruption of bladder-bowel control, saddle-shaped loss of sensation, progressive bilateral weakness. In this picture one does not wait.

Situations in Which I Recommend Early Surgery

• Progressive muscle weakness — especially foot drop or being unable to lift the toes
• A marked and deepening neurological deficit
• A picture deteriorating rapidly over a short period

In these situations, trying non-surgical treatment is a loss of time and carries the risk of permanent nerve damage.

Situations in Which Planned Surgery Comes onto the Agenda

• Pain that does not go away despite non-surgical treatment applied for an adequate period (generally at least 3 months) and that disrupts quality of life
• No response to the injection/rupture procedure, or recurrence within a short time
• A marked shortening of the walking distance (neurogenic claudication)
• A recurrent cyst and recurrent complaints

The Situation That Does Not Require Surgery

• Cysts found incidentally that cause no complaints at all. Surgery is not performed on these “as a precaution.”

Surgical Methods

Facet cyst surgery has two components: decompression (removing the cyst and making room for the nerve) and, where needed, fusion (stabilizing the segment).

Decompression: Removing the Cyst

The aim is to remove the cyst entirely and relieve the pressure on the nerve root and the dural sac.

• Hemilaminectomy: On the side where the cyst lies, part of the posterior bony structure of the vertebra is opened to reach the cyst. It is the most commonly used approach.
• Laminectomy: Applied if the cyst is large or if accompanying canal narrowing requires a wider opening.
• Microsurgery and minimally invasive/endoscopic techniques: In suitable patients, they make it possible to work through a smaller incision with less damage to the muscle tissue.

What is the technically difficult part? The cyst can adhere to the dural sac over time. Separating these adhesions without tearing the membrane (without creating a CSF leak) requires care. The surgical microscope is valuable precisely at this point.

Complete removal of the cyst is the most important condition for preventing recurrence.

Fusion: When Is It Added?

Here lies the most debated and most important section of this article.

What does the literature say? Comparative studies paint a consistent picture: cyst recurrence is markedly higher in patients who undergo decompression alone than in those who undergo decompression plus fusion. In one series of 87 patients, the recurrence rate in the decompression-only group was 11.5%, while no recurrence at all was seen in the group in which fusion was added. A systematic review and meta-analysis from 2023 confirms the same direction: in patients in whom fusion was added, cyst recurrence was markedly lower (0% versus 6.3%), and the rate of resolution of postoperative back pain was higher. In contrast, reoperation rates and rates of resolution of leg pain were similar in the two groups; in the fusion group, the hospital stay is on average about a day and a half longer.

The logic behind this is simple: the cyst is the product of instability. If you remove only the cyst, the mechanism producing it remains in place — and the cyst can form again. Furthermore, performing a wide decompression can unmask an instability that was “hidden” until then.

However, there is another side to the coin: Fusion lengthens the operation, increases bleeding, and brings its own specific risks such as failure to fuse (pseudarthrosis) and adjacent segment disease. Indeed, the literature also states clearly that there is no firm consensus on which patients must definitely undergo fusion. In other words, performing fusion on everyone is not correct either.

My Approach

When making this decision, I look not at the patient but at the segment. I ask the following questions:

I am more inclined to add fusion if:

• There is marked instability on dynamic X-rays (slippage that emerges with movement)
• Degenerative spondylolisthesis accompanies it
• The cyst is at a highly mobile segment such as L4-L5 and there is advanced facet arthrosis
• I need to sacrifice a significant portion of the facet joint to remove the cyst (if more than half of the joint is removed, stability is compromised)
• The patient also has marked back pain of a mechanical character
• We are dealing with a recurrent cyst

I am more inclined to settle for decompression alone if:

• There is no slippage on dynamic X-rays and the segment is stable
• The cyst can be removed with the facet joint largely preserved
• The dominant complaint is leg pain, with back pain not in the foreground
• The patient’s general condition could not tolerate a longer operation

In summary: I do not think “I removed the cyst, the job is done.” The real question is this: is the movement disturbance that produced this cyst still ongoing? If the answer is yes, a procedure performed without drying up the source remains incomplete.

I want to emphasize that this decision needs to be made individually for each patient, by evaluating the imaging, the examination, and the patient’s expectations together.

The Postoperative Period and Recovery

Hospital Stay

• In patients undergoing decompression only: Generally short; most patients are gotten on their feet on the day of surgery or the next day and are discharged within 1–2 days.
• In patients in whom fusion is added: The period lengthens somewhat; in comparative analyses, a stay on average about a day and a half longer has been reported.

The Pain Going Away

This is the part that most delights my patients: the pain radiating into the leg recedes markedly in most patients immediately after the operation. In some series, the great majority of patients reported that the radicular pain disappeared right after surgery.

In contrast:

• Numbness and loss of strength recover more slowly — this can take weeks, sometimes months
• In a nerve that has been under compression for a long time, full recovery may not always be possible
• Accompanying back pain generally recedes within the first weeks in patients who undergo fusion

Return to Work

This depends entirely on the person and the operation:

• Desk-based work: Generally within a few weeks after decompression
• Occupations requiring physical work: A longer period is needed
• In those who undergo fusion: Because bone fusion can take 3–6 months, the return is planned gradually

I cannot give an exact duration — the surgeon following you determines this by looking at the scope of the operation and at your recovery.

Rehabilitation

A physical therapy and trunk-strengthening program started at the time determined by your doctor both speeds up functional recovery and reduces the load on the spine.

The Likelihood of Recurrence

Let me share the honest figures:

• Recurrence after decompression alone: Although it varies by series, it has been reported in the range of 6–12%
• Recurrence after decompression plus fusion: Reported in studies as very low, and zero in some series

Furthermore, the cyst can form again not at the operated level but at another level, because the underlying degenerative process concerns the spine as a whole.

What you can do to reduce the risk of recurrence: Quitting smoking (critical for bone fusion), weight control, paying attention to ergonomics, and keeping up the recommended exercises.

Frequently Asked Questions

Below, I have gathered the most frequently asked questions on this subject along with brief answers. These answers are for general information; the information that applies to your specific situation is the one given by the doctor who examines you.

Is a facet joint cyst cancer?

No. A facet joint cyst (synovial cyst) is a benign, fluid-filled sac; it is not a tumor, it does not become cancerous, and it does not spread to other parts of the body. The problem is purely mechanical: it can press on a nerve where it sits.

Does a facet cyst resolve on its own?

It can, rarely, and such cases have been reported in the literature; however, this is the exception, not the rule. Because the facet joint wear producing the cyst remains in place, the cyst can refill even after it empties. If you have loss of strength, waiting with the thought “it will resolve on its own” is risky.

Is a facet cyst confused with a lumbar disc herniation?

Yes, very frequently. Both cause pain radiating into the leg, numbness, and loss of strength; telling them apart by examination is most often not possible. The MRI makes the distinction: a facet cyst is seen immediately adjacent to the facet joint as a bright, well-defined structure on T2 images.

Where is a facet cyst most commonly seen?

Most commonly at the L4-L5 level — in surgical series, roughly 63–68% of cases are at this level. The reason is that L4-L5 is the most mobile segment of the lumbar spine and therefore wears the most. It is generally seen in people around 60 years of age and older.

Does draining it with a needle (cyst rupture) work?

It helps in some patients; in a meta-analysis of 544 patients, the rate of satisfactory outcome was 55.8%, and 38.7% of the same group later had to undergo surgery. Compared with surgery, the rate of cyst resolution is 58% with percutaneous procedures and 90% with surgery. It is not a suitable option if there is marked loss of strength.

Will screws be placed during the operation?

Not in every patient. The screw-fusion decision is made according to whether or not there is instability (slippage emerging with movement) in that segment. If vertebral slippage accompanies it, if slippage is seen on dynamic X-rays, or if a large portion of the facet joint will be sacrificed to remove the cyst, fusion comes onto the agenda. If the segment is stable, decompression alone may be sufficient.

Does the cyst recur after surgery?

In patients undergoing decompression alone, the recurrence rate has been reported in the range of 6–12% depending on the series; in patients in whom fusion is added, this rate is very low, with no recurrence at all seen in some series. Furthermore, the cyst can form again at another level.

Will my pain go away immediately after surgery?

The pain radiating into the leg recedes markedly in most patients immediately or within a very short time. Numbness and loss of strength, on the other hand, recover more slowly; in a nerve that has been under compression for a long time, full recovery may not always be possible. This is why deciding in good time is important.

When Should You See a Doctor?

To the Emergency Department Without Losing Any Time (Red Flags)

If one of the following symptoms is present, do not wait for an appointment — go to the nearest emergency department:

• Losing control of urine or stool, incontinence or being unable to pass them
• “Saddle-shaped” loss of sensation in the anal region, the buttocks, and the inner thighs
• Suddenly starting, rapidly progressing marked loss of strength in the leg (being unable to lift the foot upward, foot drop)
• Numbness and weakness appearing in both legs at once
• Sudden loss of sexual function

These symptoms suggest cauda equina syndrome and may require surgical intervention within hours.

Make an Appointment Without Delay (Even If Not an Emergency)

• Pain radiating into the leg that is steadily increasing
• Progressive numbness in the leg
• A marked shortening of the walking distance
• Complaints that have not gone away or are increasing after 4–6 weeks
• Pain that does not go away with rest and wakes you from sleep at night
• Low back pain accompanied by fever, night sweats, or weight loss

One final reminder: Your report saying “facet joint cyst” is not in itself an emergency and does not mean that surgery will be needed. However, you do need to show this report to a doctor who examines you — because what this finding means for you can only be decided by combining the examination with the imaging.

References

1. Wun K, Hashmi SZ, Maslak J, Schneider AD, Katchko KM, Singh G, Patel AA, Hsu WK. The Variability of Lumbar Facet Joint Synovial Cyst Recurrence Requiring Revision Surgery After Decompression-only and Decompression/Fusion. Clinical Spine Surgery. 2019;32(10):E457-E461. https://doi.org/10.1097/BSD.0000000000000870
2. Benato A, Menna G, Rapisarda A, Polli FM, D’Ercole M, Izzo A, D’Alessandris QG, Montano N. Decompression with or without Fusion for Lumbar Synovial Cysts — A Systematic Review and Meta-Analysis. Journal of Clinical Medicine. 2023;12(7):2664. https://doi.org/10.3390/jcm12072664
3. Shuang F, Hou SX, Zhu JL, Ren DF, Cao Z, Tang JG. Percutaneous Resolution of Lumbar Facet Joint Cysts as an Alternative Treatment to Surgery: A Meta-Analysis. PLoS ONE. 2014;9(11):e111695. https://doi.org/10.1371/journal.pone.0111695
4. Campbell RJ, Mobbs RJ, Rao PJ, Phan K. Interventions for Lumbar Synovial Facet Joint Cysts: A Comparison of Percutaneous, Surgical Decompression and Fusion Approaches. World Neurosurgery. 2017;98:492-502. https://doi.org/10.1016/j.wneu.2016.11.044
5. Bruder M, Cattani A, Gessler F, Droste C, Setzer M, Seifert V, Marquardt G. Synovial cysts of the spine: long-term follow-up after surgical treatment of 141 cases in a single-center series and comprehensive literature review of 2900 degenerative spinal cysts. Journal of Neurosurgery: Spine. 2017;27(3):256-267. https://doi.org/10.3171/2016.12.SPINE16756
6. Bydon A, Xu R, Parker SL, McGirt MJ, Bydon M, Gokaslan ZL, Witham TF. Recurrent back and leg pain and cyst reformation after surgical resection of spinal synovial cysts: systematic review of reported postoperative outcomes. The Spine Journal. 2010;10(9):820-826. https://doi.org/10.1016/j.spinee.2010.04.010

Note: The references above are the peer-reviewed medical publications on which the rates shared in this article are based. The links direct to the official DOI addresses of the articles; full-text access to some publications may require a subscription.

Disclaimer (Legal Notice)

The information contained in this article has been prepared for general informational purposes only and in no way replaces a medical examination, diagnosis, or treatment. The rates shared above are average values taken from the studies cited; your personal situation and outcomes may differ from them. In a facet joint cyst, the choice of treatment, the necessity of surgery, and the fusion decision vary greatly according to the location and size of the cyst, the neurological findings, whether or not there is instability in the segment, and the person’s general state of health, and can only be determined by a doctor who evaluates you. Do not try to interpret your imaging report on your own; always show it to the doctor who referred you for the test. If emergency symptoms such as urinary/fecal incontinence, saddle-shaped loss of sensation, or sudden and progressive loss of strength are present, go to the nearest emergency department without losing any time.