How Does Bone Fracture Healing Occur!
May 20, 2007 by Dr Arun Pal Singh
Filed under Fractures-Dislocations, Musculoskeletal Anatomy
Healing of a fractured bone is quite a complex process but I will try to simplify.
To understand the process better we need to have an idea about the anatomy of the bone. Bone is surrounded by a thin membranous layer of tissue called periosteum ( See adjoining Figure - The figure represents a cut section through a bone. Normally the bone is like a cyllinder. Imagine cyllinder cut into halves along its longitudinal axis and you would get a similar picture. ).
When bone breaks, it bleeds from its torn ends due to disruption of its supplying vessels. Quite naturally the periosteum also is torn as shown in the figure. This periosteum may be completely torn or partially damaged depending upon the force of injury. The collected blood is called fracture hematoma.
Due to loss of vascularity or blood supply adjacent portion of broken ends die. Inflammation changes occur in the haematoma over next few hours ( A reaction by the body which occurs whenever there is an insult to a part or structure. The basic purpose of the inflammation is to contain the damage and facilitate the healing and regeneration. Inflammation is responsible for redness, pain, warmth and tenderness of the wounds and abcesses) .
This inflammation brings in many cells that would help in regeneration of the broken bone. Periosteum plays a vital role in fracture healing. The periosteum is the primary source of precursor cells which develop into chondroblasts( cartilage cells) and osteoblasts ( bone cells) that are essential to the healing of bone. as the time progresses, the fibroblasts ( A kind of cells which produce fibrous tissue in the body) get interspersed with small vesels and form a loose mesh like structure uniting the broken ends of the bone and on which the future layers of bone tissue would be added. this structue is called granulation tissue.
Over the next few days, the cells of the periosteum replicate and transform. The periosteal cells proximal to the fracture gap develop into chondroblasts and form hyaline cartilage. The periosteal cells distal to the fracture gap develop into osteoblasts and form woven bone a kind of bone which is structurally different from the lamellar bone oound in the body.
These two new tissues grow in size until they unite with their counterparts from other pieces of the fracture. This process forms the fracture callus. the callus is the first sign of union visible in x-ray and generally appears around two weeks after fracture. Eventually, the fracture gap is bridged by the cartilage and woven bone, restoring some of its original strength. A picture like this is produced.
From here on slowly and steadily bone is restructured by a process called remodeling.
Tags: bone healing, callus, fracture healing
hi Dr. Singh,
i fractured the shaft of my fifth metatarsal 14 days ago today. the doctor had a cast put on me and said i would need it for five weeks. i got another x-ray yesterday,13 days since fracture, by a different doctor and does’nt think ther has been any healing. over the years, i’ve been unfortunate enough to fracture my cheekbone, wrist, scaphoid, ankle and ribs. all of these injuries healed well and quicker than the time i was initially told they would. the cast is driving me insane as i’m due to play overseas basketball in august, and this is the last opportunity i will ever get at 27. do you think the bone should be showing signs of knitting back together by now, and if it does start to heal, when do you think would be a good time to take off the cast. please tell me what you think i should do.
andrew
Dr Arun Pal Singh Reply:
June 16th, 2009 at 4:16 pm
@andrew,
I can understand your apprehension but injury needs to heal before you can do anything.
Before I comment on your injury, I need to know th nature of injury. Was it displaced? did you have a wound?
I had a humeral fracture in Jan. 2008. After rodding in Feb. 2008 and grafting–morphogenic–in Jan. 2009, I still have no healing of the fracture. Now my orthopedic surgeon is talking compression clamp(?). What are my other options? It’s a clean break mid-shaft.
Thanks.
Dr Arun Pal Singh Reply:
June 23rd, 2009 at 4:49 pm
@Jay,
I do not think I understamd the word compression clamp
Does that mean compression plating.
Because that is a another option in these fractures.
Hi,
8 weeks ago I fell and broke my 5th metatarsal on my right foot. I was put on crutches and a boot, no cast. I just got back from the dr and he palpated the area for pain, to which I had none, but the xray clearly showed the fracture…he said it was most likely filling with soft tissue and I could walk as long as there was no pain, and if that occured to go back to the crutches and boot………….I have been able to walk about 1 hour in total in the last 4 days, but being very conservative I dont want to re-injure the healing area. I am 52 years old, very active, swim, run (well until I broke my foot), a non-smoker. He has me scheduled to come back to see him August 7 (7 weeks away - which will make 13 weeks since breaking my foot), in your opinion, is there an average time when I can resume walking? Anxious to walk again……………then maybe resume running sometime down the road.
Many thanks,
Mike
I meant to also mention, that it was not a compound fracture…..but a closed break. He also called it a Jones Fracture.
Thanks again,
Mike
Dr Arun Pal Singh Reply:
June 25th, 2009 at 4:04 pm
@MIke,
Sometimes the xray may show line for long time.
If you do not have pain, you can work towards walking gradually.
Jones fracture usually do not cause much trouble in healing. It is always difficult to put a time frame but most of people walk within 8-12 weeks with this injury.
Yes. I’m sorry–compression plating.
Thanks.
Jay
hi. i had a right humeral shaft oblique closed fracture, distal 3rd due to fall 3 weeks ago and currently on cast. surgery wasn’t performed. i chose the conservative management. how long will it heal? how many weeks ill be on cast? thank you.
Dr Arun Pal Singh Reply:
June 29th, 2009 at 1:12 am
@mike trillo,
Usual time for conservative treatment is 8-12 weeks followed by physiotherapy.
It is advisable to get frequent xrays for initial three weeks to know if position is maintained or not.
it is all the more important in distal third oblique fractures.