Bone Fracture and healing

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, …









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


Simple: Hairline (Fissure)

In repeated stress e.g. march fracture in

metatarsals Transverse Oblique Spiral


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. Remodeling bony 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

Complications of fractures 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?

Complications of fractures 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

Complications of fractures Deep Vein Thrombosis, Embolism

Caused by Increased pressure in compartment Interrupted venous return Hematoma

Complications of fractures Infection:

More in open fractures Depends on amount of contamination and tissue

necrosis Possible in closed fractures

Complications of fractures Delayed

Malunion: deformity Delayed union Non-union

Management of fractures

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

Management of fractures Assessment

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

Management of fractures 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.

Conservative - closed reduction Casts :

A cast is an immobilizing device made up of layers of plaster or fiber glass.

Allows early mobility and reduces pain

Conservative - closed reduction 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

Bone Fracture and healing

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