Bone Health and Fragility Fractures after Spinal Cord Injury: What You Should Know

After a spinal cord injury, the bones below your level of injury lose density faster than in almost any other medical situation — faster than long bed rest, or even space flight. The loss is steepest in the first two years, then continues more slowly for life. Doctors call this sublesional osteoporosis (“below the level of injury”). It mainly affects the hips, knees, and lower legs. It usually causes no pain and no symptoms, so many people do not know it is happening.

Why it matters is fractures. Bones weakened by SCI can break during ordinary activities — a transfer, a stretch, a roll in bed, or a leg that catches while dressing. These are called fragility (or low-trauma) fractures, because little or no force is involved. About half of people injured for ten years or more will break a bone at some point (per MSKTC). The good news: bone health can be watched and protected, and most of these fractures can be prevented with the right screening, routines, equipment, and follow-up.

🚨 Red Flags — When to Seek Emergency Care

Because feeling below your injury may be reduced or absent, a broken bone can happen without the pain that normally warns you. The fracture itself may be silent — so watch your legs and hips, and treat the indirect signs as the real warning.

Call your SCI physician or seek urgent care if you notice any of these after a transfer, fall, range-of-motion session, or even with no clear cause:

A loud snap, pop, or grinding you felt or heard during a transfer, dressing, or movement.
New swelling, warmth, redness, or bruising in a thigh, knee, lower leg, or ankle — especially around the knee, the most common fracture site.
A leg that looks bent, rotated, shortened, or “different” than usual.
A sudden, unexplained increase in spasticity below your injury — a fracture is a common hidden trigger.
A new episode of autonomic dysreflexia — pounding headache, sweating, flushing above your injury — with no other clear cause. A fracture can set this off in anyone injured at T6 and above (see the autonomic dysreflexia guide).
A low-grade fever or feeling generally unwell along with a swollen, warm leg.

Tell the care team: “I have a spinal cord injury. I have reduced feeling in my legs and I am at high risk for fragility fractures. Please consider a fracture even though I may not feel pain, and please take autonomic dysreflexia precautions.” A swollen, warm leg can also be a blood clot — another SCI emergency — so it always needs a prompt X-ray.

Why Bone Loss Happens After SCI

A few SCI-specific factors drive bone loss below your injury:

Loss of weight-bearing and muscle pull. Bone stays strong by being loaded. When you can no longer stand, walk, or tighten the large leg muscles, the bones stop getting the signals that keep them strong, so they rebuild thinner and weaker.
Faster breakdown than rebuilding. Healthy bone is always being broken down by one set of cells and rebuilt by another. After SCI the breakdown cells outpace the building cells, so density drops fast. It is fastest in the first few months and most severe over the first two years. In motor-complete injuries, this breakdown peaks roughly three to six months after injury; in incomplete or non-traumatic injuries the rate is less predictable (per SCIRE).
Changes in hormones, circulation, and nerve signals below the injury also play a role. Their exact effect is not fully understood, but bone loss after SCI is far greater than lack of use alone would explain.

How much bone you lose usually tracks how much muscle function remains below the injury — less function, more loss. With very high injuries, even the arms and wrists can thin (per MSKTC). But the loss is greatest, and fractures most common, at the knee — the lower thigh bone and upper shin — and the hip. Bones above your injury and your spine are much less affected.

Knowing Your Risk and Getting Screened

You cannot feel low bone density, so screening is how you find out where you stand.

Ask your SCI physician about a bone density (DXA) scan. DXA is the standard, painless way to measure bone density and estimate fracture risk. Centres with SCI expertise measure the spine, hip, and knee regions — the knee especially, because standard hip-and-spine scans can miss the bone loss that matters most after SCI (per SCIRE). A research scan called pQCT can look at the shin in detail but is mostly used in studies.
Get a DXA before starting any weight-bearing or standing program. Knowing your current bone strength lets your team judge whether loading your legs is safe (per MSKTC).
Know your personal risk factors. These add to baseline SCI risk (per SCIRE):
- being female, or a motor-complete injury (AIS A or B), or paraplegia;
- more than ten years since injury, or being young (under 16) at the time of injury;
- low body weight (BMI under 19), or heavy alcohol use;
- long-term use of anticonvulsants, blood thinners, or opioids;
- low knee-region bone density, a prior fragility fracture, or a family history of fracture.
If three or more apply to you, raise them with your care team.
Get screened after any fracture. A fragility fracture is itself a reason to formally check your bone health and future risk.
Keep a record of past fractures, your most recent DXA results, and your latest vitamin D level, so each new clinician has the full picture.
Revisit it over time. Bone status changes, especially in the first few years; review it at your regular SCI check-ups.

Protecting Your Bones: Diet, Supplements, and Medication

Bone protection after SCI works on two fronts — keeping the building blocks (calcium and vitamin D) in range, and, when risk is high, medication. Loading your bones through standing and FES is covered in the next section.

Keep vitamin D in range. Vitamin D helps your body absorb calcium, and low levels are common after SCI (less sun, diet changes, medication effects). Ask to have your level checked with a simple blood test rather than guessing. There are no SCI-specific dose guidelines. General adult advice is around 600 IU per day (800 IU over age 70), and Osteoporosis Canada suggests 800–2000 IU per day for people with osteoporosis or multiple fractures. Intakes above 4000 IU per day are generally not advised. Let your clinician set your dose (per SCIRE).
Get calcium from food first. Calcium is the main mineral in bone, but supplements alone do not reduce bone loss after SCI. High-dose calcium pills have been linked to calcium build-up in the heart arteries; calcium from food does not carry that signal. So build up food sources before adding pills. General adult targets are about 1000–1200 mg per day. If you have bladder or kidney stones, you may need less — check with your clinician (per SCIRE).
Ask about medication if your risk is high. When bone density is very low, or you have already had a fragility fracture, your doctor may discuss bone-strengthening drugs:
- Bisphosphonates (such as alendronate, risedronate, etidronate, zoledronic acid) slow bone breakdown. They are the best-supported option for reducing density loss in the hip and knee, especially when started early — often within the first three months after injury. They can be taken by mouth or by IV. Whether they actually lower the SCI fracture rate is still not certain, and they have side effects (heartburn, stomach upset, jaw or thigh pain) and specific dosing rules to discuss first (per SCIRE).
- Denosumab and recombinant parathyroid hormone (PTH) are other options used later after injury to keep or increase hip- and knee-region density.
- Any of these is an individual decision made with your SCI physician, weighing benefit against side effects.
Don’t smoke, and keep alcohol moderate. Both weaken bone and slow healing, and heavy alcohol use raises fracture and fall risk.
Stay active and keep a healthy weight. General fitness and good nutrition support bone and lower fall risk (see the Exercise & Fitness and Nutrition & Weight Management guides).

Loading Your Bones: Standing, FES, and What the Evidence Shows

Putting healthy stress back through your legs is appealing, and standing and FES have other real benefits — circulation, digestion, mood, spasticity, and pressure relief. But it helps to know what the bone evidence actually says, so you set realistic expectations.

Start any loading program only with your rehab team, and only after a DXA, so they can weigh your bone strength against the risk of loading a fragile leg.
Supported standing and weight-bearing (standing frame, tilt-table, braces, treadmill or body-weight-supported stepping) are widely used. But the evidence that they maintain or improve bone density after SCI is not clear — they have not been shown to reliably rebuild bone (per SCIRE).
FES cycling (electrical stimulation that makes paralyzed leg muscles work) does not prevent the fast bone loss right after injury, but it may raise density in the stimulated areas in the later period after SCI. The catch: the benefit fades once the stimulation stops, so it has to be ongoing to hold (per SCIRE).
Passive exercise alone (being moved without muscle contraction) does not prevent the dramatic early bone loss in people who are more severely paralyzed and cannot bear weight (per MSKTC).
Therapeutic ultrasound and whole-body vibration are not supported for treating SCI bone loss — current evidence shows no benefit (per SCIRE).
The honest bottom line: medication (bisphosphonates) is the best-supported way to slow SCI bone loss; the non-drug physical treatments are not yet proven for bone. Do them for their other benefits and for the chance of stimulated-area gains — not as a substitute for screening and follow-up.

Preventing the Everyday Injuries That Break Bones

Most SCI fractures happen during routine activities — transfers most of all — so prevention is mostly about technique, equipment, and how helpers handle you.

Use safe transfer technique every time. Most fractures happen during wheelchair or bed transfers, usually by twisting or catching a leg or foot. Avoid dragging or banging your legs against the chair, bed frame, or toilet; a transfer board and an extra moment of care protect your bones.
Train everyone who helps you. Fractures can happen when someone holds you a certain way. Caregivers should support — never pull, force, or twist — your legs during transfers, dressing, range-of-motion, and repositioning.
Be gentle with range-of-motion and stretching. Slow, supported movements only; stop at resistance. Never let anyone force a stiff or spastic joint. Even simple acts — stretching, rolling over in bed — have caused fractures.
Prevent falls. Lock your brakes, use a well-fitted wheelchair and seatbelt, keep pathways clear, and watch for a foot catching on the ground or a front caster.
Protect your legs during activities and travel — watch for legs slipping off footplates, catching in doorways, or getting pinned in a vehicle.
Treat spasticity well. Strong, uncontrolled spasms can stress fragile bones; managing spasticity protects your skeleton too.

If a Fracture Happens: What to Expect

Knowing the path ahead helps you act fast and ask the right questions.

Get an X-ray promptly. A red or swollen leg should always prompt imaging to rule out a fracture — early detection prevents bigger problems.
Treatment varies by site. Fractures are often managed with bracing and a period of rest to let the bone heal; surgery is needed in some cases. As a general pattern, fractures above the knee are more often fixed with surgery, while those below the knee are more often casted (per SCIRE).
Healing can be slower after SCI, so follow your team’s plan closely.
Watch for complications — which is part of why prompt care matters: blood clots, skin breakdown and pressure injuries from bracing or bed rest, bone infection, reduced range of motion, contractures, worse spasticity, and abnormal calcium build-up around the fracture site (per MSKTC).

When to Call Your Doctor or Rehab Team (Non-Emergency)

You have never had a bone density scan, or it has been several years.
You want to start standing, FES, or a weight-bearing program and need a DXA and a safe setup first.
Your vitamin D has not been checked recently, or you are unsure about your calcium and vitamin D plan.
You have new or worsening spasticity, or any leg swelling that comes and goes.
You have had a previous fracture, or three or more risk factors, and want to discuss bone-protecting medication.

What Many People Find Helpful

Many people treat bone protection as part of the same daily “maintenance” mindset as skin, bladder, and bowel care — quiet, routine, and worth it.
Some keep a short written transfer-and-handling note for new caregivers: “Support my legs, never pull or twist, watch for swelling.”
People who use standing frames or FES often build them into a weekly routine so it becomes a habit — and many value the other benefits even where the bone payoff is uncertain.
After any hard knock, twist, or rough transfer, many people make a habit of glancing at and feeling along their legs for swelling, warmth, or a change in shape. Catching a fracture early prevents bigger problems — and a swollen, warm leg always earns an X-ray, since it could be a fracture or a clot.

Evidence & Sources

Synthesized from SCIRE Community evidence summaries (osteoporosis and bone health after SCI) and MSKTC SCI factsheets (bone loss after SCI) (retrieved 2026-06-24). See RESEARCH-SOURCES.md for complete provenance and cross-bucket details. The clinical detail on the pattern of sublesional bone loss, knee-region screening, supplement ranges, medication options, and the limits of physical treatments draws on the SCIRE Community osteoporosis summary and the MSKTC “Bone Loss After Spinal Cord Injury” factsheet.

Keep the 🚨 Red Flags block in the upper half. A fracture may cause no pain. The warning signs are a snap or pop, swelling or warmth (especially at the knee), a change in leg shape, new spasticity, or unexplained autonomic dysreflexia.
A swollen, warm leg always needs a prompt X-ray — it can be a fracture or a blood clot.
Screening: ask about knee-region DXA; get one before any standing/FES program.
Diet: food calcium first; check and dose vitamin D with your clinician.
Medication: bisphosphonates (started early) are the best-supported way to slow loss; ask if your risk is high.
Standing/FES help other things and may aid stimulated areas, but are not proven to rebuild bone — keep up screening and follow-up regardless.
Prevent the everyday breaks: safe transfers, trained helpers, gentle range-of-motion, fall-proofing.
If your printer drops the emoji, write “RED FLAGS — POSSIBLE FRACTURE” by hand at the top.

Bone loss after SCI is common, silent, and largely preventable in its consequences. You may not be able to feel a weak bone or a fracture, so the plan is simple. Get screened (ask about knee-region DXA). Keep vitamin D and calcium in range. Ask about medication if your risk is high. Load your bones safely if your team approves. Protect your legs during every transfer and movement, and check your legs after any rough handling. Share this guide with your caregivers and your care team, and keep it where you can find it.