Cement Surgery for Compression Fractures — BKP, VBS, and Why the Window Closes When the Bone Heals

• What "cement surgery" actually is
• Why it is only possible before the bone heals
• Which fractures qualify
• What the hospital stay looks like
• The risks, and what this surgery cannot do
• What remains possible if the window has closed
• Options if pain remains (SCS)
• Costs and coverage

Contents: What it is | Timing | Which fractures qualify | The process | Risks | After the bone heals | Residual pain | Costs | When to see a doctor | FAQ

Your spine is a stack of bone blocks called vertebrae. When osteoporosis weakens them, a vertebra does not snap like a stick. It crumples under the load from above and below. That is a compression fracture.

The procedures that reinforce a crumpled vertebra from the inside, through a needle-sized entry in the back, are collectively called percutaneous vertebral augmentation. There is no large incision. Three main methods exist:

• PVP (percutaneous vertebroplasty): medical bone cement is injected directly into the collapsed vertebra to stabilize it. It is the simplest method and is aimed mainly at pain. It can do little to restore the collapsed shape.
• BKP (balloon kyphoplasty): a small balloon is inflated inside the vertebra to lift the collapsed bone from within, and the cavity it creates is then filled with bone cement. It aims to relieve pain and also to restore the shape.
• VBS (vertebral body stenting): after the balloon lifts the bone, a small metal scaffold called a stent is left inside the vertebra as an internal support. With BKP, some of the regained height is lost when the balloon is deflated. The stent holds the lift in place to prevent this.

All three are low-burden procedures: most patients are up and practicing walking the day after surgery. Being elderly does not by itself rule them out. The decision rests on your overall condition (heart, lungs, other illnesses), and the anesthesia plan is chosen to match.

A fractured bone heals by hardening. That is normally good news, but a compression fracture can heal in its collapsed shape. And once the bone has hardened, no balloon or stent can lift it afterward. Think of clay: while it is soft, you can reshape it; once it sets, the shape is fixed.

So the shape can be rebuilt only while the fracture has not yet healed.

Two points are often misunderstood.

There is no "within X weeks" rule. Bones heal at different speeds in different people. What decides is the current state of the bone, not the number of days since the injury, and only imaging can show that.

Months passing does not mean nothing can be done. When a fracture fails to heal and keeps hurting (a state called nonunion), surgery can still help even long after the injury. The approved indication for VBS in Japan, once limited to acute fractures, was broadened in 2025 to include painful chronic fractures.

So the costliest mistake is deciding "it must be too late" on your own.

Not every compression fracture needs cement surgery. Most compression fractures heal with conservative care, meaning a brace and careful rest. Surgery comes into the picture roughly when:

• pain stays severe despite conservative care
• X-rays show the collapse is progressing
• the bone fails to heal and pain drags on (nonunion)

On the other hand, the shape of the fracture matters. If the back wall of the vertebra is badly broken, if the collapse is very severe, or if the fracture is markedly unstable, cement augmentation alone may not be enough. Screws and rods may need to be added, or a fixation surgery chosen from the start.

Which method fits is decided from X-ray, MRI, and CT images of the individual fracture. Two fractures with the same name can be very different inside, so the conversation starts with a doctor who has seen your images.

Details differ between hospitals, but a rough map makes the surgeon's explanation easier to follow.

Before surgery. The fracture is assessed with imaging, and your general condition is checked: heart, lungs, and current medications, particularly blood thinners. General anesthesia is common, though the plan depends on your condition.

The surgery. Lying face down, a needle-sized entry is made in the back, and a thin tube is guided into the vertebra under X-ray. The balloon lifts the bone (in VBS, the stent is then deployed), and bone cement is injected. The cement hardens within minutes and becomes the pillar that supports the vertebra. The procedure itself takes around 30 minutes.

Afterward. Most patients begin sitting up and walking practice the next day. A hospital stay of several days to about a week is typical, depending on the fracture and your condition. A brace may be used for a period afterward.

After discharge (the most important part). Cement surgery supports the one broken vertebra; it does not treat the osteoporosis itself. Continuing osteoporosis treatment is the single best protection against the next fracture.

These are low-burden procedures, but no surgery is risk-free. Knowing the main points in advance makes the informed-consent discussion easier.

• Cement leakage. Injected cement can escape the vertebra. Most leaks cause no symptoms, but rarely they can affect nerves. That is why studying the fracture's shape and choosing a leak-resistant technique are part of the surgical plan. VBS was designed so that cement is injected into the scaffold's frame, making the flow easier to control.
• New fractures elsewhere. After surgery, a neighboring vertebra can fracture. This is largely because the whole spine remains fracture-prone, which is another reason to continue osteoporosis treatment.
• The shape does not fully return. There is a limit to how much height can be regained, and the surgery cannot promise the original shape.
• Pain can have more than one source. Back pain often has overlapping causes, and supporting the fracture may not remove all of it.

Once the vertebra has healed in its collapsed shape, cement surgery can no longer restore it. That does not mean the road ends.

When pain or the postural collapse is severe enough to need correction, there is a larger operation: the healed vertebra is removed and replaced with a titanium mesh cage (a metal pillar), and the spine is rebuilt with screws and rods. Alignment can be restored this way even after healing. But the burden on the body, and the length of the hospital stay, are of a different order than cement surgery.

And even without surgery, options remain: pain management, bracing, rehabilitation, and osteoporosis treatment to prevent the next fracture. If the bone has healed crooked, something can still be done, but the options are different.

Timing decides whether you find out while a small procedure is still possible, or only when a large one remains.

Even after the fracture has settled, whether it healed with conservative care or was supported surgically, some patients are left with ongoing low back pain. The load of a changed posture, and the way prolonged pain can teach the nervous system to keep signaling (chronification), are thought to lie behind it.

For chronic low back pain lasting beyond three months, there are options that treat the pain itself. One of them is spinal cord stimulation (SCS), a minimally invasive surgical treatment in which thin leads placed near the spine deliver very mild electrical pulses that soften the pain signal. Its main features:

• Before anything is implanted, a trial stimulation over several days lets you test whether it works for you
• The stimulation can be turned off, and the device can be removed later, so the treatment is reversible
• In Japan it is covered by national health insurance (availability and coverage differ by country)

You can read more on our sister site, supervised by the same doctor:

• Video: SCS for Chronic Back Pain
• Article: SCS for chronic low back pain

In Japan, BKP and VBS are both covered by national health insurance, and the high-cost medical care benefit (高額療養費制度) caps your out-of-pocket payment for an expensive month; arranging a limit certificate in advance keeps even the counter payment within the cap. The details are collected in our article on treatment costs.

A note for readers outside Japan: availability differs by country (BKP is widely available internationally, while VBS availability varies), and the insurance details above describe the Japanese system. Please check coverage under your own healthcare system.

• Sudden, severe back pain deserves an X-ray at an orthopedic clinic. Do not write it off as age. A compression fracture cannot be distinguished from a pulled back by feel.
• If you are already "watching and waiting": when pain stays severe for 2–3 weeks without easing even at rest, go back and have the bone re-checked.
• If the bone has not yet healed, that is also a sign that options are still open.

You get checked early to know your options while you can still choose among them, whichever you then choose. It does not commit you to surgery.

Q. It has been two months since my fracture. Is it too late?

The calendar alone does not decide. If the bone has failed to heal and still hurts, surgery can help even after months. Only imaging can tell, so rather than concluding "it must be too late," have an orthopedic surgeon look.

Q. Can my 85-year-old parent undergo this?

Age itself matters less than overall condition (heart, lungs, other illnesses), how active they were before the fracture, and what they themselves want. These are low-burden procedures performed widely in elderly patients. One question makes the discussion concrete: "How would my parent's daily life likely differ with surgery versus without?"

Q. Is bone cement safe in the body? Does it last?

Bone cement has been used in orthopedic surgery for decades. It hardens within minutes and then stays permanently as the pillar inside the vertebra. It does not dissolve or wear away. The main risk is leakage at the time of injection, discussed above.

Q. Can I have MRI scans afterward?

Bone cement and titanium implants generally do not prevent MRI scanning. The final judgment depends on the specific device and scan conditions, so always tell the imaging staff about your surgery in advance and confirm with your doctor and the imaging facility.

Q. Can I stop my osteoporosis treatment after the surgery?

No. The surgery supports the broken vertebra, but the osteoporosis is still there. Continuing treatment is the single best protection against the next fracture, with or without surgery.

Q. Will I still need a brace?

Often yes, for a period after surgery. The duration depends on the fracture; follow your surgeon's guidance. Our guide to living with a brace may help.

• Vertebral Compression Fractures: how a collapsing bone changes posture and invites the next fracture
• Recovery Timeline After a Compression Fracture: what conservative healing looks like, stage by stage
• Stopping the Fracture Cascade: making the first fracture the last
• What Treatments Exist After a Fracture?: conservative care, surgery, and osteoporosis treatment
• Osteoporosis and Money: costs and the public programs that help

On VBS outcomes in Japanese patients — a domestic multicenter prospective study of 88 patients reporting early pain relief and maintenance of the restored vertebral height at one year:

• Takemasa R, et al. Effectiveness and Safety of Vertebral Body Stenting for Acute Spinal Compression Fractures due to Primary Osteoporosis: A Multicenter Prospective Clinical Study. Spine Surg Relat Res. 2024;8(4):415-426. PMID: 39131414

On the comparison of BKP and VBS — a systematic review finding equivalent pain relief, with VBS favored for height maintenance and lower cement leakage:

• Zhang T, Peng Y, Li J. Comparison of clinical and radiological outcomes of vertebral body stenting versus percutaneous kyphoplasty for the treatment of osteoporotic vertebral compression fracture: a systematic review and meta-analysis. Jt Dis Relat Surg. 2024;35(1):218-230. PMID: 38108184

On the statement that shape can be rebuilt only while the fracture has not healed — the UK health technology appraisal restricts these procedures to "recent, unhealed vertebral fractures":

• National Institute for Health and Care Excellence (NICE). Percutaneous vertebroplasty and percutaneous balloon kyphoplasty for treating osteoporotic vertebral compression fractures. Technology appraisal guidance TA279. 2013.

Additional reference:

• Japanese Orthopaedic Association, Clinical Practice Manual on Osteoporotic Vertebral Fractures. J Jpn Orthop Assoc. 2020;94:882-906 (in Japanese)

This article provides general medical information and does not recommend any particular diagnosis or treatment. Surgical indication differs from person to person with the fracture's shape, timing, and your overall condition. Please consult your own doctor about your treatment.