This document summarizes the process of fracture healing, which occurs in three overlapping phases: hemorrhage and clot formation (first 10 days), callus formation (10-20 days), and remodeling (2-3 years). It describes the six stages of fracture healing according to Weinman and Sicher: clotting, organization, fibrous callus formation, primary bony callus formation, secondary bony callus formation, and functional reconstruction. Complications like delayed union, nonunion, malunion, and cross union are also summarized.

1. FRACTURE HEALING
Presented By
Dr. Naveen Lalchandani

2. Introduction
• Fracture is break in the continuity of bone,
which may be a sequel of RTA, interperso-
nal violence, fall from hight, due to a
pathology etc.
• Healing of fracture starts immediately after
the fracture occurs.
• Bone heals faster than the cartilage because
bone has better blood supply than cartilage.

3. Fracture Healing
Healing of bone occurs in three overlapping phases-
• Hemorrhage followed by the clot organisation and proliferation of blood
vessels.(first 10 days)
• Than callus formation, rough woven bone or primary callus(10-20 days),
followed by secondary callus in which haversian system forms(20-60 days).
• Functional reconstruction and remodelling occurs in third phase, mechanical
forces are important in this phase, the haversian system lined up according to
the stress lines.
• The shape of the bone is molded to conform with functional usage so that
bone may be added to one surface and removed from the other side.(2-3 yr).

4. Weinman and Sicher divide the healing of bone in six stages
1) Clotting of blood of the hematoma
2) Organisation of the blood of the hematoma
3) Formation of fibrous callus
4) Formation of primary bony callus
5) Formation of secondary bony callus
6) Functional reconstruction of the fractured bone

5. Clotting of the blood of the hematoma
• When fracture occurs the blood vessel of the surrounding
structures are ruptured.
• The resultant hematoma completely surrounds the fractured
ends and extends upto the bone marrow and adjacent soft
tissue.(coagulates after 6-8 hr after fracture)

6. Organisation of the blood of hematoma
• A meshwork of fibrin is formed in the organizing hematoma.
• It contains fragments of periosteum, muscles, fascia, bone and bone
marrow.
• Inflammatory cells, which is important for the haemorrhagic phase of bone
healing are called forth by this diseased tissue rather than bacterial
organism.
• Capillaries and fibroblast invades the clot in 24 to 48 hours.

7. Cont…
• The proliferation of blood vessel is characterstic of early organising
hematoma.
• The capillary beds in the marrow, cortex and periosteum become small
arteries to supply the fracture site. Thuse increasing the blood supply at the
site.
• At this stage, proliferation of capillaries occurs throughout the hematoma.
• The hyperaemia associated with the slow flow of blood through tortous
vessel results in mesenchymal proliferation.

8. • The resorption of bone is the characterstic of older hematoma.
• The flow of blood running through the active hyperemia, and not disuse
atrophy causes resorption of bone.
• When the blood gets into the actual site of fracture where the capillary bed
lies, the flow is slowed, this area of passive hyperemia is associated with
proliferation of bone.
• Calcium ion is increased in this area by capillary bed.

9. Formation of fibrous callus
• The organised hematoma is replaced by the granulation tissue ordinarily in 10 days.
• It removes the necrotic tissue primarily by phagocytic activity.
• Conversion of granulasion tissue into loose connective tissue.
• In the end of the hyperemic phase there is decrease in the white blood cells and
partial obliteration of capillaries.
• Fibroblast are now most common among cells and forms numerous collagenous
fibers known as fibrous callus.

10. Formation of primary bony callus
• Forms within 10-30 days after fracture.
• The calcium content is so low in this, so it can not be
assessed with a radiograph.
• It is an early stage that provides only mechanical prop
for the formation of secondary callus.

11. Primary callus has been considered in different
catogaries , depending on its location:
1. Anchoring callus developes on the outside surface of the bone near the
periosteum. It extends some distance away from the fracture. Young
connective tissue cells of the fibrous callus differentiate into osteoblast,
which produce this spongy bone.
2. Sealing callus developes on the inside surface of the bone across the
fractured end. It fills the marrow space and goes out into the fractured
site. It forms from endosteal proliferation.

12. 3. Bridging callus developes on the outside surface between the two
fractured ends. This callus is the only one which is primarily cartilaginous.
4. Uniting callus forms between the ends of bones and between the area of
primary calluses that have formed on the two fractured parts. It does not
form until the other forms of calluses are well developed. It forms by
direct ossification, extensive resorption of bone ends occurs by this time.
Therefor, rather than marely ossifying the interposed connective tissue at
the site, the uniting callus forms in the area of resorption as well.

14. Formation of secondary bony callus
• Secondory bony callus is mature bone that replaces the immature bone of
the primary callus.
• It is more heavily calcified, and therefor it can be seen on the radiograph.
• It differs from the other skeletal bones however, by the fact that the
pseudohaversian system is not formed in any uniform pattern, it is
compossed of laminated bone and withstand pressure.
• Therefor fixation can be removed in this stage, formation of secondary
callus is slow process, it takes 20-60 days.

15. Functional reconstruction of the fractured bone
• Reconstruction proceeds over months or year, where the location of the
fracture cannot be detected radiographycally or anatomically.
• Mechanics is the major factor in this stage, the fact is, if the bone is not
subjected to functional stress, true mature bone will not form. True
haversian system that are oriented by stress factors are replaced by
pseudohaversian system of secondary callus.

16. • The entire bone is molded by mechanical factors if the healing has not taken
place in exact alignment.
• Stress are reduced in one side and deficiencies are filled in another side.
• This process seems to take place in alternative waves of osteoclastic activity
and osteoblastic activity.

17. Comlications of fracture healing
1. Delayed union
2. Non union
3. Mal union
4. Cross union

18. Delayed/ Nonunion
• When a fracture takes more than the usual time to unite it is said to
have gone in delayed union.
• When the process of healing stops before completion the fracture is
said to have gone for non union. To diagnose non union the
fracture has to be minimum six months old.

20. Causes
• Related topatient
Old age
Associated systemic illness: ex.Malignancy
• II. Related to fracture
Distraction at fracture site Muscle pulling the fragments: ex. # mandibular body.
Gravity:
Soft tissue interposition:
Bone loss during fracture: ex. # any open fracture
Infection from open fracture:
Damage to blood supply of fractured site
Pathological fracture: ex. # osteomyelities

21. • III causes related to treatment:
Inadequate reduction:
Inadequate immobilisation
Distraction (excessive) during treatment
Types
1. Atrophic: no or minimal callus formation
2. Hypertrophic: callus is present but it does not bridge the fracture
site.

22. Clinicalfeatures
Pain
Deformity
Abnormal mobility
Radiological findings
• Delayed union: inadequate callus, visible fracture line
• Non union: ends are rounded, smooth sclerotic.
• Medullary cavity may be obliterated. visible fracture line.

23. Treatment: Delayedunion
1. Most commonly prolonged conservative management
2. Surgical intervention: bone grafting with or without internal
fixation.

24. Treatment: nonunion
• Depends upon site and resulting disability. Following are the options.
1. Bone grafting: commonest.
2. Excision of fragments: when it can be done with minimal loss
of function. Aprosthesis may be used to replace the lost part.
3. No treatment: when there is no disability

25. Mal union
• When a fracture does not unite in proper position it issaid to have
malunited.
• Causes:
1. Improper reduction
2. Unchecked muscle pull
3. Excessive communication

26. Consequences
• Deformity
• Limitation of movements

27. Management
• Refracture and ORIF.
• No treatment may be necessary if remodelling occurs.

28. THANK YOU