Old vs. New Bone after Limb Lengthening Surgery

I wanted to talk about a simple but common question I get quite often and that’s “if the newly formed bone after limb lengthening is as strong as your bone pre-surgery?”

How bones heal

When most soft-tissues like the skin or muscle are damaged they’ll heal with scar tissue which, although it’s stronger than before, can look different than normal and possibly impact the way it functions. But a broken bone will heal itself with actual bone and not scar tissue and go back to its original texture pre-fracture, break or lengthening and can be hard to see even on an x-ray.

Now the rate at which this healing happens differs based on age and other health or hygiene factors. Younger patients tend to heal faster than those significantly older and those who are healthy will heal faster than those who don’t smoke or vape.

Phases of Bone healing

So there are 3 distinct phases of bone healing. 

 Phase 1 is the inflammatory phase where your body’s immune system will create a hematoma which is a blood clot at the site of the break. This is so your body can send in the clean up crew to heal the damage. 

Phase 2 takes place within a few days after the surgery so your body can form this envelope-like-cocoon, or spongy callus, around the break so new bone regenerate can form at the site of break. This is why you don’t start lengthening right away.

It’s as the callus forms with bone matrix into the bony callus that you then start distracting the ends apart slowly so that bony fragments are gradually regenerated via the magical process, we all know and love known as distraction osteogenesis aka limb lengthening. 

Phase 3 is the remodeling stage where the cloudy bony matrix in the lengthening gap starts to break down via osteoclasts and rebuild via osteoblasts. You might know this phase as the consolidation phase where you are rebuilding new bone cortices so you can weight bear which will continue to remodel overtime into rock-solid-compact bone that you’ll need to get back to running, jumping, sprinting, heavy lifting and even combat sports.

The actual appearance may remain a bit distorted for many years later due to the hypertrophic stimuli to reinforce the break site. But it will function just as good as before.