When someone breaks a bone, pain is often the first thing people think about. But pain is only part of the story. New research shows that nerves inside bones help guide healing, not just signal pain.
Two recent studies published in Science help explain how this works and why it is important to understand NGF, or nerve growth factor.
What Is NGF and Why Is It Important?
NGF is a natural protein made by the body that helps nerves:
- Grow and stay alive
- Respond to injury
- Communicate with other cells
NGF is well known for its role in pain, but it also helps nerves stay healthy so they can support healing. This makes NGF important not just for pain, but also for recovery after injury.
What Happens When a Bone Breaks
Bones contain many tiny nerve fibers. When a bone breaks:
- These nerves send pain signals to the brain
- At the same time, they release signals that help healing begin
New research shows that nerves are active helpers during bone repair, not just messengers of pain.
What the Studies Showed
One Science article showed that nerves in bone release growth signals that help bone cells repair a fracture. Pain signals and healing signals can come from the same nerves.
The second Science article looked more closely at how nerves behave over time after a fracture. The researchers found that:
- Early on, nerves focus on pain signaling
- Later, those same nerves switch roles and help healing
They identified an important healing signal called FGF9, which helps new bone form. When nerve signals were blocked, bones healed more slowly and less completely.
How NGF Connects to Both Studies
NGF helps nerves survive and function after injury. Healthy nerves are needed to:
- Release healing signals like FGF9
- Support new bone growth
- Coordinate repair over time
If NGF activity is reduced too much, nerves may not work properly. This could affect both pain and healing.
Why This Matters for Pain Treatment
Because NGF is involved in pain, it has been targeted by certain pain medications. These treatments can reduce pain by blocking NGF signals.
But these studies remind us of something important:
Nerves do more than cause pain. They also help tissues heal.
If NGF or nerve signaling is blocked too strongly, pain may be reduced, but healing could also be slowed.
What This Means for Pets
Pets also rely on nerves and NGF for healing. Dogs and cats have similar nerve and bone biology to people.
Medications that block NGF, such as bedinvetmab or frunevetmab, are used to help manage arthritis pain in pets. While these drugs can improve comfort, this new research raises an important question:
Could blocking NGF also interfere with bone healing?
Right now, we do not have clear proof that these medications delay bone healing in pets. However, because NGF helps nerves support healing, it is possible that blocking NGF during a fracture or after bone surgery could affect recovery.
This does not mean these medications are unsafe. It means timing matters. Pain control should always be balanced with healing, especially in pets that:
- Have fractures
- Recently had orthopedic surgery
- Are healing from bone injuries
Veterinarians may need to carefully consider when to use NGF-blocking medications and when to pause them during active bone healing.
The Big Takeaway
- Nerves help guide bone healing, not just produce pain
- NGF keeps those nerves healthy and working
- Pain control and healing are closely connected
- Blocking NGF may help pain but could affect healing timing
Understanding NGF helps veterinarians and doctors protect both comfort and recovery at the same time.
You can find the two articles here
Xu et al.: https://www.science.org/doi/10.1126/science.adr9608
Rosen and Gori: https://www.science.org/doi/10.1126/science.aed9273
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