Bone Fracture and healing Prof. Mamoun Kremli AlMaarefa College

Bone Fracture and healing

Prof. Mamoun KremliAlMaarefa College

Definition of Fracture

A break in the continuity bone

Often associated with soft tissue injury Soft tissue injuries might be more serious

than the fracture

Etiology

Motor Vehicle Accident Fall Sport injuries Vigorous Exercise Bone Diseases

Osteoporosis Osteomyelitis Cyst, …

Etiology



Etiology



Etiology



Etiology



Types of Fracture

Ordinary Caused by a force Normal bone

Pathological Caused by trivial force Diseased (weak) bone

Types of Fracture

Ordinary Caused by a force Normal bone

Pathological Caused by trivial force Diseased (weak) bone

Osteoporosis Osteomyelitis Tumour, cyst, ..

Types of Fracture

Incomplete Fracture line is incomplete Only one cortex is broken

Complete Fracture line is complete Bothe cortices are broken

www.childrensmemorial.org/

www.childrensmemorial.org/

Types of Fracture

Incomplete Green-stick

One cortex is broken Other cortex is bent

In children

Lee P et al. Radiographics 2004;24:1009-1027

Types of Fracture

Complete Simple:

One fracture line Two bone fragments

Comminuted: More than one fracture line More than two bone fragments More soft tissue injuries

Types of Fracture

Complete Simple:

Hairline (Fissure) In repeated stress e.g. march fracture in

metatarsals Transverse Oblique Spiral

Types of Fracture

Complete Comminuted:

Butterfly Segmental Multiple fragments Compression

Types of Fracture

Undisplaced Normal alignment

maintained

Displaced Deformed from

normal alignment

Types of Fracture

Closed Skin intact

Compound (Open) Skin not intact Communicating to

outside

Types of long bone fractures

Metaphyseal Diapyseal Articular Epiphyseal

(children)

Sign and Symptoms of Fracture

Pain Swelling Deformity Local tenderness Loss of function

Diagnostic Evaluation

X-ray The most useful

MRI, CT-scan In suspected cases In intra-articular fractures

Fracture Healing

Stages of fracture healing: Hematoma Inflammation Repair Remodeling

1. Hematoma

Bleeding caused by vessel rupture Hematoma collects Bone at fracture edges dies

Rockwood and Green

2. Inflammation

Inflammatory cells accumulate Inflammatory mediators (cytokines) New blood vessels proliferate

Rockwood and Green

2. Inflammation

Mesenchymal cells accumulate After 1 week forms granulation tissue Osteoclasts remove necrotic bone at

fragment ends growth factors stimulate the proliferation and

differentiation of mesenchymal stem cells Formation of connective tissue

3. Repair

Connective tissue differentiates Cartilage and fibrous tissue form

Soft callus formation (2-3 weeks) Movement at fracture stimulates more callus

Rockwood and Green

3. Repair - Tissue Differentiation

connective tissue

granulation tissue

Giemsa stain

3. Repair Vascular and cellular response leads to tissue

differentiation and mineralization resulting in restoration of mechanical integrity

Fibrocartilage mineralizes (converts callus to woven bone)

Tissue Differentiation Cascade

Cartilage formation BoneMineral deposition

Masson-Goldner

Callus Formation

Periosteal callus forms along the periphery of the fracture site

Intramedullary callus forms in the center of the fracture site Endochondral ossification at the site of the

fracture hematoma

Chemical and mechanical factors stimulate callus formation and mineralization

Callus Formation Stability adequate in axial plane Angulation can still occur

fracture ends linked together by soft callus hard callus stage starts & lasts until fragment

ends are firmly united by new bone (3-4 m)

www.landesbioscience.comRockwood and Green

4. Remodeling

Woven bone slowly replaced by lamellar bone (few months to years) Medullary cavity is reconstituted Bone is restructured in response to stress and

strain

Fracture healing - summary1. Inflammation

Hematoma Mesenchymal cells

2. Soft callus Granualation tissue Fibro-cartilage

3. Hard callus Intramembranous bone

formation Enchondral ossification

4. Remodelingbony bridging

Fracture healing - summary

Summary

Prerequisites for Bone Healing

Adequate blood supply Adequate mechanical stability

If either is lost: results in delay in bone healing or no healing

occurs Smoking causes delay in bone union or

nonunion

Complications of fractures

Early: Shock Compartment syndrome Fat embolism Deep vein thrombosis, embolism Infection

Delayed Malunion Delayed union / Nonunion


Shock loss of blood Fractured femur could bleed 2L easily Fractured Pelvis could bleed 4L easily Open fractures with vascular injuries

What is the normal blood volume? How much bleeding could be tolerated?


Compartment syndrome The compression of nerves, blood

vessels, and muscle inside a closed body space (compartment)

Causes tissue death from lack of oxygenation due to the blood vessels being compressed by the raised pressure within the compartment

More common in Forearm and leg (why?)

http://www.answers.com/topic/compartment-anatomy


Deep Vein Thrombosis, Embolism Caused by

Increased pressure in compartment Interrupted venous return Hematoma


Infection: More in open fractures

Depends on amount of contamination and tissue necrosis

Possible in closed fractures


Delayed Malunion: deformity Delayed union Non-union

Management of fractures

First aid: ABC Other injuries Cover wounds Bone immobilization Definitive treatment of fracture


Assessment Type, location and severity of fracture Soft tissue damage Age and health status of patient Affection of other parts or organs


Goals: To regain and maintain correct position and

alignment. To regain the function of involved part. To return the patient to usual activities in the

shortest time and at the least expenses.

Definitive treatment of fractures

Conservative Simple fractures More in children

Operative More complex fractures Articular fractures More in adults

Conservative - closed reduction

Is the most common non surgical method for managing a simple fracture.

Splints: as upper extremity bones do not bear weight,

splints may be sufficient to keep bone fragments in place.


Casts : A cast is an immobilizing device made up of

layers of plaster or fiber glass. Allows early mobility and reduces pain


Traction: Application of a pulling

force to a part of the body Uses a system of ropes,

and weights to provide reduction, alignment and rest

Open reduction / internal fixation

Achieves perfect reduction Permits early mobilization

It is often preferred for elderly patients who are susceptible complications of immobility

Best for adults and in intra-articular fractures Uses pins, screws, rods, plates, .. After bone union, the metal may be removed,

depending on the location and type of fracture

Examples of internal fixation

Screws Wires Nails

Open reduction, internal fixation

Forearm fractures in adults (Plates)

Nail in Tibial Fractures

Intramedullary Nail

Plate for comminuted Femur fracture

Intra-articular fracture

External fixation

Ideal for open fractures where wound care is needed and operation is hazardous Often used temporarily until wounds recover

Image fromC. Turen MD

External fixationNail later

Summary

What is a fracture Types of fractures Fracture healing and requirements Management

Documents

Bone Fracture and healing Prof. Mamoun Kremli AlMaarefa College