Endoscopic facet cyst removal

In one minute

A synovial cyst (a fluid-filled sac that grows out of a worn facet joint into the spinal canal) can press on a nerve root and cause sciatica or claudication (leg pain on walking). Endoscopic facet cyst removal takes the cyst out through a 7 mm incision, usually under local anaesthesia with sedation, without screws or fusion. It is for a cyst that causes leg symptoms, has not settled with non-surgical care, and sits in a stable segment. Most patients walk the same day and go home within 24 hours.

What the operation is

Facet joints are lined with a membrane that makes joint fluid. When the joint wears and becomes lax, that lining can bulge through the capsule and form a cyst against the nerve root or the dura (the sac around the nerves). More than 90% arise at L4-L5, the most mobile lumbar level, and they are widely read as a sign that the joint is loose. They are also called juxtafacet, facet joint or extradural cysts.

The endoscopic operation removes the cyst and its wall, shaves the inner edge of the facet joint where the cyst came from, and frees the nerve; the rest of the joint, the lamina and the muscles are left alone. Open removal does the same through a midline cut with a hemilaminectomy (removal of half the lamina), often combined with fusion when the joint is unstable.

Who it is for

The operation is for a cyst that compresses a nerve root or the dura on MRI (magnetic resonance imaging), with matching leg pain, numbness, weakness or claudication, after non-surgical care has failed or when a neurological deficit appears. The AO Spine clinical practice recommendations of 2026 give a conditional recommendation for endoscopic removal as a first-line operation in patients without instability.

Percutaneous rupture, in which the cyst is burst with a needle under X-ray and steroid injected, gives immediate relief in about two thirds of patients, but in a series of 101 only a third kept the benefit and 54% needed surgery within a mean of 0.7 years. Decompression with fusion is preferred when the segment is unstable: a mobile spondylolisthesis (a slip of one vertebra on the next), a disrupted facet, or instability expected after decompression. In a comparison of 167 patients, every cyst recurrence followed decompression alone (8% after laminectomy, 4% after hemilaminectomy) and none followed fusion.

So the rule is: stable segment, endoscopic removal; unstable segment, fusion. In a 48-patient endoscopic series, a wide, fluid-filled joint gap on MRI predicted the patients whose results were only fair.

How it is done

You lie face down. Local anaesthesia with sedation is possible for this operation: a 2022 series in the Journal of Neurosurgery: Spine treated 25 patients awake, as outpatients, through the transforaminal route, and a Chinese series of eight used local anaesthesia with monitored sedation. Most of our endoscopic decompressions are done that way; the anaesthetist and surgeon decide per patient.

The route depends on where the cyst sits: in the largest prospective endoscopic series, 24 of 35 cysts were removed through the interlaminar window from the back and 11 through the foramen from the side. The incision is 7 mm. Through the endoscope the surgeon opens a small window in the lamina, separates the cyst from the dura, to which it is often stuck, and removes the wall with the fluid. The edge of the facet joint where the cyst arose is trimmed so that the source is treated as well as the sac. The incision takes one stitch. Median operating time in that series was 78 minutes.

Endoscopic compared with open surgery

The evidence is smaller than for discectomy or stenosis and there is no randomised trial.

• The prospective multicentre series of 35 patients (Tacconi and colleagues, 2020): leg pain fell from 6.8 to 3.4 after surgery and to 2.1 at six months on a 10-point scale, and 89% were pain free or improved at a median of 15 months. Two dural tears (6%) healed without further treatment; two patients had recurrent pain treated without surgery.
• The 48-patient series of Hellinger and Lewandrowski (2020): at two years, 40% excellent, 38% good and 23% fair; leg pain fell from 8.1 to 1.8.
• The awake transforaminal series of 25 patients (2022): leg pain from 7.6 to 2.3 at two years, no complications or recurrences; nine had cysts that formed after an earlier laminectomy.

The largest pooled analysis (1,251 patients, 2023) found that endoscopic resection had recurrence and revision rates not significantly different from open resection, which itself had 6.4% recurrence and 11.3% revision; resection with fusion had no recurrences and 6.7% revision. A 2023 meta-analysis of 657 patients likewise found less back pain and fewer recurrences after fusion, with no difference in reoperation or complication rates. Fusion lowers recurrence at the cost of a bigger operation; in the 167-patient comparison a dural tear was nearly three times as frequent with fusion.

Risks and how we reduce them

• Dural tear. The cyst is often stuck to the dura, so this is the risk to name first: 2 of 35 (6%) in the prospective series, both in transforaminal cases and both healed without treatment. The cyst wall is separated from the dura under magnification and continuous irrigation, and a small tear can be sealed during the same operation.
• Transient dysaesthesia (burning in the leg): 3 of 11 transforaminal cases in the prospective series, none in the awake transforaminal series. The AO Spine appraisal favours the interlaminar route where the cyst can be reached that way.
• Recurrence: 4% to 8% after open decompression alone in the 167-patient comparison. For the 35-patient endoscopic series the two accounts differ: the authors' abstract reports two recurrences of leg pain managed without surgery, while the AO Spine appraisal of the same series counts three later fusions, two of them for cyst recurrence; we quote both rather than choose. Removing the cyst wall and treating the joint edge it came from, rather than draining the sac alone, is the operation's answer to recurrence.
• Later fusion: three of 35 in the prospective series, as counted by AO Spine, and two of 48 in the two-year series. Instability is checked on standing and bending X-rays before the decision, and fusion is named plainly when it is the better choice.
• Incomplete relief: 23% fair results in the 48-patient series, linked to facet instability on the preoperative MRI.
• Conversion to open surgery: four of 35 in the prospective series. Infection: none reported in the series above.

Across the team's own operations, complications have been well below 1%. That is our figure, not a comparison with anyone else.

Recovery, week by week

Day 0. Walking the same day; home within 24 hours for most. In the prospective series leg pain had already halved by discharge.

Days 1 to 3. Short walks, no lifting, no long sitting.

Week 2. Leg pain is usually clearly better; some tingling is common after the transforaminal route. Desk work is often possible.

Week 6. Physiotherapy starts; physical jobs and sport are discussed at this visit.

Month 3 to 6. In the prospective series leg pain reached 2.1 out of 10 at six months. A new leg pain after a pain-free interval is the signal to check for recurrence.

Year 1 and 2. In the two-year series, 77% excellent or good. Cyst recurrence, or ongoing back pain with a slipping joint, is the reason a minority go on to fusion.

What the evidence says

• AO Spine, Global Spine Journal 2026: conditional recommendation for endoscopic removal in stable segments, fusion when unstable; evidence quality low.
• Tacconi and colleagues, World Neurosurgery 2020: 35 patients, prospective, three centres; 89% pain free or improved at 15 months, two dural tears.
• Hellinger and Lewandrowski, Journal of Spine Surgery 2020: 48 patients at two years; 77% excellent or good, fair results linked to facet instability.
• Ganga and colleagues, Journal of Neurosurgery: Spine 2023: 1,251 patients pooled; endoscopic recurrence and revision not different from open resection; fusion lowest.
• Benato and colleagues, Journal of Clinical Medicine 2023: 657 patients; fusion gives less back pain and fewer recurrences, same reoperation and complication rates.

How we do it at spine.uz

We are Tashkent's first endoscopic spine team: five surgeons operating as one team, 27,600+ endoscopic and spine operations in total. The incision is 7 mm, most endoscopic decompressions are done under local anaesthesia with sedation rather than general anaesthesia, and no screws or implants are used for decompression. When the joint is unstable and fusion is the honest answer, we perform it fully endoscopically.

Send your MRI on Telegram or WhatsApp. A doctor from the team replies by voice within 48 hours, free of charge, saying whether the cyst is the cause of your symptoms, whether the segment looks stable enough for endoscopic removal alone, and what we would do if it is not. The in-person consultation ends with a written team conclusion, and follow-up continues in the same chat.

Preparing for the operation

Bring the MRI files, standing and bending X-rays if you have them, since they show whether the joint is slipping, reports of any previous spine surgery, a list of your medicines, and someone to take you home. Tell us about blood thinners, diabetes and heart or lung conditions; the anaesthetist decides what to stop and when to stop eating.