fracture and fracture healing

Fracture and fracture healing

Jongkolnee Settakorn, MD, MSc, FRCPath

Objectives

• บอกลั�กษณะของ bone fracture ชนิ�ดต่�างๆ *• วิ�นิ�จฉั�ย bone fracture แบบง�ายๆ จากการด�

film x-ray *• บอกกลัไก fracture healing *• บอกปั�จจ�ยที่� เก� ยวิข"องก�บ fracture healing *• ที่ราบภาวิะแที่รกซ้"อนิของ bone fracture• สามารถปัระมวิลัควิามร�"ที่�)งหมดเข"าด"วิยก�นิ เพื่, อ

ปัระย-กต่.ใช"ก�บผู้�"ปั1วิยต่�อไปัในิอนิาคต่

Scopes

• Description of bone fracture

• Mechanism and incidence of bone fracture

• Fracture healing

• Treatment

• Complication

Bone fracture (broken bone)

• Definition: – A disruption in the integrity of a living bone

– A break in the continuity of bone

• Involving– Bone strength

– Site of bone

– Force

– Direction of force

Description of bone fracture

Common terms used to describe fractures• Bone, location• Skin integrity• Extent• Displacement• Angulation• Rotation• Morphology• Energy• Joint involvement• Soft tissue involvement

SiteBone names (femur, tibia, ..)

Bone location• Proximal

• Shaft

• Distal

• Epiphysis

• Metaphysis

• Diaphysis

• Growth platehttp://www.nytimes.com/imagepages/2007/08/01/health/adam/8856Fracturetypes2.html

http://www.drrathresearch.org/clinical_studies/condition_bonefracture_print.html

Skin

• Closed fracture (intact skin)

• Open fracture (wound on skin with bone exposure) http://www.lamrt.org.uk/incidents05.html

Extent

– Complete fracture: separate completely

– Incomplete (greenstick) fracture: partially joined

http://www.nytimes.com/imagepages/2007/08/01/health/adam/8856Fracturetypes2.html

Displacement

• Anterior

• Posterior

• Medial

• Lateral

• Proximal shortening (gapping)

• Distal lengthening (gapping)

http://www.merck.com/mmpe/sec21/ch309/ch309b.html

Angulation and rotation

• Anterior angulation

• Posterior angulation

• Medial angulation

• Lateral angulation

• Internal rotation

• External rotation

http://www.merck.com/mmpe/sec21/ch309/ch309b.html

Morphology• Linear fracture: parallel to long axis of bone

• Transverse fracture: cut cross the long axis

• Oblique fracture: diagonal to the long axis

• Spiral fracture: twisted

• Compression fracture: common in vertebrae

• Compact (impacted) fracture: bone fragments are driven into each other

• Pathologic fracture: with underlying bone lesion

http://www.merck.com/mmpe/sec21/ch309/ch309b.html

Energy

• Low energy: simple fracture (one line, two pieces)

• High energy: multi-fragmentary fracture or comminuted fracture

http://www.nytimes.com/slideshow/2007/08/01/health/100077Bonefracturerepairseries_3.html

Joint and growth plate involvement

• Extraarticular

• Intraarticular

http://www.merck.com/mmpe/sec21/ch309/ch309b.html

Soft tissue involvement: nerve, vessel, muscle, fat, skin damage

http://www.emedicine.com/Orthoped/topic636.htm

Classification of fracture, for

• Communication among clinicians

• Decision making

• Potential problems

• Treatment options

• Predicting outcome

• Documentating cases

• OTA Classification

• Oestern and Tscherne Classification of closed fractures

• Gustilo and Anderson classification of open fractures

• Salter-Harris classification of epiphyseal plate injury

OTA Classification

• The Orthopaedic Trauma Association

• Classification system to describe the injury accurately and guide treatment

• Standard for orthopedics surgeon

• Classification adaptable to the entire skeletal system

• Allows consistency in research

To Classify a Fracture: OTA

• Which bone?

• Where in the bone is the fracture?

• Which type?

• Which group?

• Which subgroup?

Oestern and Tscherne Classification of closed fractures

Grade Soft tissue injury Bony injury0 Minimal Simple fracture pattern

Indirect injury to limb1 Superficial abrasion/ Mild fracture pattern

contusion2 Deep abrasion with skin Severe fracture pattern

or muscle contusionDirect trauma to limb

3 Extensive skin contusion Severe fracture patternor crushSevere damage to underlying muscleSubcutaneous avulsion, compartmental syndrome

Gustilo and Anderson classification of open fractures (type I – type III)

• Type I: – Clean wound smaller than 1 cm in diameter

– Simple fracture pattern

– No skin crushing

• Type II: – a laceration larger than 1 cm

– No significant soft tissue crushing

– Fracture pattern may be more complex.

Gustilo type I

• Type III: – Contamination : soil ,water , yard ,fecal– Open segmental fracture or a single fracture with

extensive soft tissue injury– Any opened fracture older than 8 hours

Type IIIA: adequate soft tissue coverage of the fracture despite high energy trauma or extensive laceration or skin flaps.

Type IIIB: inadequate soft tissue coverage with periosteal stripping. Soft tissue reconstruction is necessary.

Type IIIC: any open fracture that is associated with vascular injury that requires repair.

Gustilo typeIII

Salter-Harris classification

of epiphyseal plate injury

Mechanism and incidence of fracture

http://orthoinfo.aaos.org/topic.cfm?topic=a00412

Fracture distal radius, Colles fracture

http://thedoctornotes.blogspot.com/2008/04/ilizarov-method-2.html

Opened fracture right tibial shaft

Fracture healing

Prerequisites for Bone Healing

• Adequate blood supply

• Adequate mechanical stability

• Proper bone metabolism

• Periosteum

• Bone marrow

Fracture healing process• Absolute stability : Direct (primary) bone healing:

rigidly stabilized fracture with fracture surface held in contact

eg. transverse diaphyseal fracture of radius and ulnar treated by ORIF

• Relative stability : Indirect (secondary) bone healing: unstable closed fracture, not rigidly stabilized

eg. closed clavicle fracture without surgery• Inadequate stability : non union (pseudoarthrosis)

1. Healing with absolute stability

- Rigidly contact between bone ends

- Gaps

Rigidly contact between bone ends

• Lamellar bone can form directly across the fracture line– A cluster of osteoclasts cut across the

fracture line

– Osteoblasts (following the osteoclasts) deposit new bone

– Blood vessels follow the osteoblasts

– New haversian system formation

Gaps between bone ends

• Prevent direct extension of osteoclast– A Osteoblasts fill the defects with woven bone

– A cluster of osteoclasts cut across the woven bone

– Osteoblasts (following the osteoclasts) deposit new bone

– Blood vessels follow the osteoblasts

– New haversian system formation

2. Healing with relative stability

- Hematoma

- Granulation tissue

- Soft callus

- Hard callus

- Remodeling

Hematoma between the fracture ends, in medullary canal, subperiosteal, around bone

Death bone at both ends of fracture site due to loss of nutrition

Inflammatory mediators from platelets, dead cells

Inflammtory cells migrate to the fracture site cytokine angiogenesis and stem cells migration fibroblasts, chondroblasts, osteoblasts

Vascular dilatation edema

Granulation tissue formation

Primitive mesenchymal cells (stem cells) at fracture site proliferation / differentiation into fibroblasts, chondroblasts, osteoblasts

=Soft callus=

Matrix (collagen, woven bone, cartilage)

= Cartilaginous callus =

Bone replaces cartilage by enchondral ossification

= hard callus =

=Remodeling =

Replacement of woven bone by lamellar bone

- Osteoclastic resorption

- Formation of new bone along line of stress

http://www.bonefixator.com/

Variables that influence fracture healing

• Injury variables

• Patients variables

• Tissue variables

• Treatment variables

Injury variables

• Open fractures

• Segmental fractures

• Intra-articular fracture

• Severity of injury

• Soft tissue interposition

• Damage to blood supply

• Single limb or multiple injuries

Patient variables

• Age

• Co-morbidities e.g. diabetes

• Nutrition

• Systemic hormones

• Drugs

• Nicotine and other agents

Tissue variables

• Bone necrosis

• Bone disease

• Infection

• Supply

Treatment variables

• Apposition of fracture fragments

• Loading and micromotion

• Fracture stabilization

• Treatments that interferes with healing

Treatment and complication

Treatment• General aim of management

– Control hemorrhage– Pain relief– Prevent ischemia-reperfusion injury– Remove contamination– Reduction– Immobilization

• For maximal function and minimized complication

Treatment• Non operative therapy

– Casting after an appropriate closed reduction– Traction (rarely used)

• Skin traction• Skeletal traction

• Surgical therapy– Open reduction and internal fixation (ORIF)

• Kirschner wires (K-wires)• Plates and screws• Intramedullary nails

– External fixation

:www.flickr.com/photos/onepointzero/529498016/

http://www.emedicine.com/Orthoped/topic636.htm

http://www.emedicine.com/Orthoped/topic636.htm

หน้�า: www.rad.washington.edu/.../orthopedic-hardware

http://www.emedicine.com/Orthoped/topic636.htm

http://www.emedicine.com/Orthoped/topic636.htm

Complications of fracture• Neurologic and vascular injury

• Compartment syndrome: anterior leg

• Infection: open fracture and surgery

• Thromboembolic events

• Avascular necrosis: femoral head and neck

• Post-traumatic arthritis

• Delay union, non-union, malunion

Complications

• Cast– Pressure ulcers

– Thermal burns

– Thrombophlebitis

– Prolonged cast disease: circulatory disturbances, inflammation, osteoporosis, chronic edema, soft tissue atrophy, joint stiffness

Complications

• Traction lack of patient mobility– Pressure ulcers

– Pulmonary / Urinary infection

– Permanent footdrop contracture

– Peroneal nerve palsy

– Pin tract infection

– Thromboembolic events (deep vein thrombosis, pulmonary embolism)

Complications

• External fixator– Pin tract infection

– Pin loosening or breakage

– Interference with joint motion

– Neurovascular damage

– Malalignment

– Delay union or malunion