What happens when a bone breaks?
A bone fracture occurs when the force placed on a bone exceeds its load-bearing capacity. It may happen in an accident, a fall or a blow during sport – there can be countless causes. A hip fracture is one of the most dangerous types of bone fracture and requires special rehabilitation.
At the moment of the fracture, the continuity of the bone is disrupted, and the body immediately starts the repair process.
Bone healing has four main phases:
1. Inflammatory phase (first days): A haematoma (collection of blood) forms at the fracture site, and inflammatory cells flow into the area. This phase causes pain and swelling, but it is essential for healing.
2. Soft callus formation (1-3 weeks): The body starts building cartilage tissue at the fracture site. This “soft callus” cannot yet bear weight, but it already connects the broken ends.
3. Hard callus formation (3-12 weeks): The cartilage tissue gradually turns into bone tissue. The bone becomes stronger, but it has not yet reached its final strength.
4. Remodelling phase (months-years): The bone gradually regains its original shape and strength. This is the longest phase.
Magnetotherapy produces its beneficial effect in phases 2, 3 and 4, while it may also help during the inflammatory phase.¹
Key point
Bone healing is a four-phase process: inflammation → soft callus → hard callus → remodelling. Magnetotherapy may primarily support callus formation in phases 2-4, but it may also help during the inflammatory phase.
Symptoms of a bone fracture
The symptoms of a bone fracture are usually clear. At the moment of the fracture, you feel sharp, stabbing pain that worsens with movement. The fractured area quickly starts to swell, and a haematoma (blue-purple discolouration) may also appear.
In more serious cases, the shape of the limb may change – visible deformity indicates that the bones have moved out of position. In an open fracture, the broken bone ends pierce the skin – this requires urgent care because of the risk of infection.
Moving the fractured limb is painful or impossible. If you experience any of these symptoms, see a doctor immediately!
Diagnosis and treatment of a bone fracture
Although the symptoms are often clear, an X-ray is needed to diagnose the fracture accurately. It shows the type of fracture and the position of the bone ends, and determines the treatment method.
Why immobilisation matters: Stable immobilisation is essential for a fractured bone to heal. The fractured area is fixed with a cast or modern plastic supports (orthoses) so that the bone ends do not move. Immobilisation is uncomfortable, but without it a proper callus cannot form.
My advice
If you have a fracture, make sure you receive suitable immobilisation! Although it is uncomfortable, it ensures the development of strong bone. Loading the limb too early or using inadequate immobilisation may lead to prolonged healing and the development of a nonunion.
Acute pain relief: Pain caused by the fracture may be relieved with medicines, cooling and TENS treatment.
How long does a bone fracture take to heal?
Healing time depends on several factors:
| Factor | Effect on healing |
|---|---|
| Age | Faster in younger people |
| Fracture location | Limb fractures heal faster than spinal fractures |
| Type of fracture | A simple fracture heals faster than a comminuted fracture |
| General health | Chronic diseases may slow healing |
| Smoking | Slows healing considerably |
| Nutrition | Calcium and vitamin D deficiency slows healing |
In general, 6-12 weeks are needed for most fractures to heal. During this time, the limb cannot be loaded and the immobilisation must be worn.
When is fracture healing considered prolonged?
If the fracture heals more slowly than expected, we speak of delayed fracture healing (delayed union). If there is no meaningful progress after 6-9 months, a nonunion may develop – the broken ends do not join, resulting in persistent pain and loss of function.
Causes of prolonged healing may include:
- Inadequate immobilisation (the bone ends move)
- Insufficient blood supply at the fracture site
- Infection
- Smoking
- Certain medicines (steroids, long-term NSAID use)
- Diabetes, atherosclerosis
- Osteoporosis – weak bone structure slows healing from the outset
Treating a nonunion is challenging – another operation is often needed. This is where magnetotherapy may have a role as a complementary treatment.
What is magnetotherapy and how does it affect bone healing?
Magnetotherapy – or PEMF (Pulsed Electromagnetic Field) therapy – uses a low-frequency, pulsed electromagnetic field. The FDA (US Food and Drug Administration) has authorised PEMF for the treatment of nonunions since 1979 – this was one of its first officially recognised applications.²
But how does a magnetic field affect a fractured bone?
Osteoblast stimulation: The magnetic field stimulates the activity of bone-forming cells (osteoblasts). Research has shown that PEMF increases the production of BMP-2 and BMP-4 (bone morphogenetic proteins), which play a key role in bone formation.¹
TGF-β and growth factors: PEMF treatment increases the production of TGF-β (transforming growth factor beta), which stimulates the differentiation of mesenchymal stem cells into bone-forming cells.¹
Enhanced angiogenesis: The magnetic field may support the formation of new blood vessels at the fracture site, improving the supply of nutrients and oxygen.³
Activation of the Wnt/β-catenin pathway: PEMF may activate this important signalling pathway, which is one of the main regulators of bone formation.¹
What does scientific research say?
The effect of magnetotherapy on fracture healing has been assessed in numerous scientific studies.
A 2020 systematic review and meta-analysis – which analysed 22 randomised controlled trials and 1468 patients – found that PEMF treatment:
- Increased the healing rate by 22% (79.7% vs. 64.3% in the control group)
- Reduced pain
- Shortened healing time⁴
The researchers concluded that convincing-quality evidence supports PEMF increasing the fracture-healing rate and reducing pain.⁴
Particularly good results were achieved in the treatment of nonunions. A study following 1382 patients found an 89.6% success rate for PEMF treatment of nonunions.⁵ Earlier studies reported healing rates of 73-85% in nonunions.²
In a 2012 prospective clinical study, bone union was achieved with PEMF treatment in 77.3% of patients with delayed healing of tibial fractures.⁶
A 2013 randomised controlled trial assessed early treatment of delayed fracture healing. The PEMF-treated group achieved a 77.4% success rate, compared with 48.1% in the control group.⁷
Important to emphasise
Magnetotherapy is a complementary treatment. Appropriate immobilisation and, where necessary, surgery are the basis of fracture treatment – PEMF complements them; it does not replace them.
How should you use magnetotherapy for a bone fracture?
You can start magnetotherapy immediately after immobilisation! The magnetic field passes through the cast, so you do not have to wait for it to be removed.
Recommended treatment protocol for a bone fracture:
| Parameter | Fresh fracture | Prolonged healing / Nonunion |
|---|---|---|
| Daily treatment time | 4-6 hours | 6-8 hours |
| Treatment duration | 30-45 days | 3-5 months |
| Intensity | According to the programme | According to the programme (+50% with a cast) |
Positioning the treatment coil: Place the flexible applicator over the fracture site. If the limb is in a cast, place it on the cast – the magnetic field passes through it. Ideally, the coils should be positioned on opposite sides of the fracture, facing each other (with opposite polarity), so that the magnetic field crosses the fracture.
My advice
With a cast or thick support, increase the intensity by 50%, because the distance reduces field strength.
When can you expect results? Bone tissue regenerates slowly. Usually, a change can be seen on a follow-up X-ray after 4-8 weeks of regular treatment. Treating nonunions takes longer – 3-5 months may be needed.
Before you start treatment
Magnetotherapy is generally safe, but there are conditions in which it must not be used.
When must you NOT use magnetotherapy? (Absolute contraindications)
Do NOT use the device if you have:
- An implanted cardiac pacemaker
- An implanted defibrillator
- An insulin pump or other implanted electronic device
- Pregnancy
Increased caution is required (Relative contraindications)
Consult your doctor if you have:
- An active infection at the fracture site
- Cancer
- A metal implant at the fracture site (screws and plates generally do not cause a problem, but ask your doctor). If the fracture was fixed with screws or plates, magnetotherapy can generally be used – and may even support implant integration.
- Severe circulatory disorder
Important
Magnetotherapy is intended to complement medical treatment. Follow the immobilisation instructions, attend follow-up examinations and follow your doctor’s advice!
Possible side effects
Side effects of magnetotherapy are rare and usually mild. According to the 2020 meta-analysis, there is no significant difference in the occurrence of side effects between the treatment and control groups.⁴
The following may occasionally occur:
- A mild feeling of warmth in the treated area
- Temporary increase in pain (rare, usually at the beginning of treatment)
If you experience any persistent or unusual symptoms, consult your doctor.
Which device should you choose for treating a bone fracture?
For treating a bone fracture, you need a magnetotherapy device with a dedicated fracture-healing programme.
Every member of the Globus Magnum device family includes a bone fracture treatment programme:
Magnum L
1-channel, entry-level device for treating one limb.
Magnum XL
2-channel, 280 Gauss.
Magnum 2500
2-channel, 320 Gauss, 52 programmes.
Magnum XL Pro
2-channel, 400 Gauss.
Magnum 3000 Pro
2-channel, 400 Gauss, 70 programmes.
For treating a bone fracture, the flexible applicator (30x10 cm) is ideal, as it wraps around the fractured limb. This accessory is included as standard with every device, so you do not need to purchase it separately.
Additional supportive treatments during fracture healing
Besides magnetotherapy, other physiotherapy methods may also support rehabilitation.
Preventing muscle loss during immobilisation
During cast or support use, muscles quickly waste away – visible muscle loss may occur within just 4-6 weeks. Muscle stimulators create muscle contractions with electrical impulses without moving the joint. This allows you to exercise muscles not covered by the cast and reduce muscle loss.
After immobilisation is removed
When the cast is removed, you may be surprised: the muscles are weak and the joints are stiff. If the fracture affected the lower limb, knee pain may also occur during rehabilitation. In addition to physiotherapy:
- Therapeutic ultrasound: Helps loosen stiff ligaments and tendons and restore the joint’s range of motion.
- TENS treatment: If rehabilitation is accompanied by pain.
Summary – Quick overview
| Term | Meaning |
|---|---|
| Callus | New bone tissue formed at the fracture site |
| Delayed union | Prolonged fracture healing |
| Nonunion | The fractured bones do not join |
| PEMF | Pulsed electromagnetic field – the scientific term for magnetotherapy |
| Osteoblast | Bone-forming cell |
| BMP | Bone morphogenetic protein – a key factor in bone formation |
- Stimulates the activity of bone-forming cells (osteoblasts)
- Increases the production of growth factors (BMP-2, TGF-β)
- Supports blood-vessel formation at the fracture site
- Activates the Wnt/β-catenin bone-forming pathway
Frequently asked questions
Immediately after immobilisation (application of the cast)! The magnetic field passes through the cast, so you do not have to wait for it to be removed.
With a fresh fracture, a change can be seen on a follow-up X-ray after 4-8 weeks of regular treatment. With nonunions, 3-5 months may be needed.
Generally yes – modern osteosynthesis materials are not magnetisable. However, always consult your treating doctor.
Daily, for at least 4-6 hours (fresh fracture) or 6-8 hours (nonunion). Regular use is key.
NO! Magnetotherapy is prohibited with a pacemaker or an implanted defibrillator.
Related articles
Sources
- Cadossi R, Massari L, Racine-Avila J, Aaron RK. (2020). Pulsed Electromagnetic Field Stimulation of Bone Healing and Joint Preservation: Cellular Mechanisms of Skeletal Response. J Am Acad Orthop Surg Glob Res Rev, 4(5):e1900155. PubMed: 33970582
- Chalidis B, Sachinis N, Assiotis A, Maccauro G. (2011). Stimulation of bone formation and fracture healing with pulsed electromagnetic fields: Biologic responses and clinical implications. Hippokratia, 15(Suppl 1):12-19. PubMed: 21669132
- Wang A, Ma X, Bian J, et al. (2024). Signalling pathways underlying pulsed electromagnetic fields in bone repair. Front Bioeng Biotechnol, 12:1333566. PubMed: 38328443
- Peng L, Fu C, Xiong F, et al. (2020). Effectiveness of Pulsed Electromagnetic Fields on Bone Healing: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Bioelectromagnetics, 41(5):323-337. PubMed: 32495506
- Murray HB, Pethica BA. (2016). A follow-up study of the in-practice results of pulsed electromagnetic field therapy in the management of nonunion fractures. Orthop Res Rev, 8:67-72. PubMed: 30774471
- Assiotis A, Sachinis NP, Chalidis BE. (2012). Pulsed electromagnetic fields for the treatment of tibial delayed unions and nonunions. A prospective clinical study and review of the literature. J Orthop Surg Res, 7:24. PubMed: 22681718
- Shi HF, Xiong J, Chen YX, et al. (2013). Early application of pulsed electromagnetic field in the treatment of postoperative delayed union of long-bone fractures: a prospective randomized controlled study. BMC Musculoskelet Disord, 14:35. PubMed: 23331333
