MUSCULOSKELETAL MUSCULOSKELETAL BLOCKBLOCK

Pathology PathologyLecture 1: Fracture and bone Lecture 1: Fracture and bone

healinghealing

Dr. Maha ArafahDr. Maha Arafah

Dr. Abdulmalik Alsheikh, MD, Dr. Abdulmalik Alsheikh, MD, FRCPCFRCPC

MUSCULOSKELETAL MUSCULOSKELETAL BLOCKBLOCK

Pathology: 5 lecturesPathology: 5 lectures1.1. Fracture and bone healingFracture and bone healing

2.2. Congenital and developmental bone Congenital and developmental bone diseasesdiseases

3.3. Introduction to myopathies and Introduction to myopathies and muscular dystrophymuscular dystrophy

4.4. Non-infectious arthritisNon-infectious arthritis

5.5. Osteomyelitis and septic arthritisOsteomyelitis and septic arthritis

Healing of bone Healing of bone fracturesfractures

At the end of this lecture you should :At the end of this lecture you should : Know the different types of fracturesKnow the different types of fractures Be aware of the mechanism and stages of Be aware of the mechanism and stages of

fracture healing processfracture healing process Know the factors affecting healing process Know the factors affecting healing process

and the possible complications of healing and the possible complications of healing processprocess

Appreciate the importance of road traffic Appreciate the importance of road traffic accidents as a major cause of disability in accidents as a major cause of disability in Saudi ArabiaSaudi Arabia

Normal Normal anatomyanatomy

Parts of a long Parts of a long bones:bones: epiphysisepiphysis (ends of bone, (ends of bone,

partially covered by partially covered by articular cartilage)articular cartilage)

physisphysis (growth plate) (growth plate) metaphysis metaphysis (junction of (junction of

diaphysis and epiphysis, diaphysis and epiphysis, most common site of most common site of primary bone tumors)primary bone tumors)

diaphysisdiaphysis (shaft) (shaft)

metaphysis

Normal Normal anatomyanatomy

Cross section:Cross section: PeriosteumPeriosteum cortex cortex

(composed of (composed of cortical bone or cortical bone or compact bone)compact bone)

medullary space medullary space (composed of (composed of cancellous or cancellous or spongy bone)spongy bone)

Normal histologyNormal histology

Lamellar bone:Lamellar bone: layered bone with layered bone with

concentric parallel concentric parallel lamellaelamellae

gradually replaces gradually replaces woven bonewoven bone

normal type of bone normal type of bone found in adult found in adult skeletonskeleton

stronger than woven stronger than woven bonebone

Bone: mineralized osteoid; either lamellar bone or woven bone.

Osteoblasts:Osteoblasts: arise from marrow arise from marrow mesenchymal cells; when active, are mesenchymal cells; when active, are plump and present on bone surface; plump and present on bone surface; eventually are encased within the eventually are encased within the collagen they produce.collagen they produce.

Osteoclasts: large multinucleated Osteoclasts: large multinucleated cells found attached to the bone cells found attached to the bone surface at sites of active bone surface at sites of active bone resorption.resorption.

Fracture:-Fracture:- Break in the continuity of Break in the continuity of bonebone

Defintions.Defintions.

Complete

Incomplete

Defintions.Defintions.

Closed fracture (simple).Closed fracture (simple).

Open fracture (compound).Open fracture (compound).

Complicated fracture.Complicated fracture.

Defintions.Defintions.

Closed Closed Fracture Fracture (simple ):-(simple ):-

Does Does NOTNOT communicate with communicate with external external environmentenvironment

Defintions.Defintions.

Open Open Fracture Fracture (compound ):-(compound ):-

CommunicateCommunicate with external with external environmentenvironment

Infection !!Infection !!

Defintions.Defintions.

Fracture Fracture Dislocation:Dislocation:--

Always X-Ray JointAlways X-Ray Joint

Above and BelowAbove and Below

Defintions.Defintions.

ComplicateComplicated Fracture:-d Fracture:-

Associated Associated with damage to with damage to nerves, vessels nerves, vessels or internal or internal organsorgans

Causes of fracturesCauses of fractures Traumatic fracture: Sever traumaTraumatic fracture: Sever trauma Pathological fracture:Pathological fracture:

Fracture occur with minimal trauma Fracture occur with minimal trauma the underlying bone is abnormal e.g.the underlying bone is abnormal e.g.

OsteoporosisOsteoporosis   OsteomalaciaOsteomalacia     Paget's disease of bonePaget's disease of bone   PrimaryPrimary or  or metastatic tumormetastatic tumor. .

Stress fractureStress fracture

Stress fractureStress fracture

A stress fracture is generally an overuse injury. It occurs when muscles become fatigued or overloaded and can not absorb the stress and shock and repeated impact. Fatigued muscles transfer that stress to the nearby bone and the result is a small crack or fracture, in the bone.

Healing of fracturesHealing of fractures

1. 1. Reactive PhaseReactive Phase i Fracture and inflammatory phase i Fracture and inflammatory phase

ii. Granulation tissue formation ii. Granulation tissue formation

2. 2. Reparative PhaseReparative Phase iii. Callus formation iii. Callus formation

iv. Lamellar bone deposition iv. Lamellar bone deposition

3. 3. Remodeling PhaseRemodeling Phase v. Remodeling to original bone contour v. Remodeling to original bone contour

Excellent Reduction with Excellent Reduction with Well Molded CastWell Molded Cast

How does a fracture heal? How does a fracture heal? Stage 1: Inflammation Stage 1: Inflammation Bleeding from the fractured bone Bleeding from the fractured bone and surrounding tissue causes the and surrounding tissue causes the fractured area to swell. This stage fractured area to swell. This stage begins the day you fracture the bone begins the day you fracture the bone and lasts about 2 to 3 weeks.and lasts about 2 to 3 weeks.

Reparative PhaseReparative Phase Soft callus Soft callus 

Between 2 and 3 weeks after the injury, the pain Between 2 and 3 weeks after the injury, the pain and swelling will decrease. At this point, the site and swelling will decrease. At this point, the site of the fracture stiffens and new bone begins to of the fracture stiffens and new bone begins to form. The new bone cannot be seen on x-rays. form. The new bone cannot be seen on x-rays. This stage usually lasts until 4 to 8 weeks after This stage usually lasts until 4 to 8 weeks after the injury.the injury.

Hard callus Hard callus Between 4 and 8 weeks, the new bone begins to Between 4 and 8 weeks, the new bone begins to bridge the fracture. This bony bridge can be seen bridge the fracture. This bony bridge can be seen on X-rays. By 8 to 12 weeks after the injury, new on X-rays. By 8 to 12 weeks after the injury, new bone has filled the fracture.bone has filled the fracture.

Bone remodeling Bone remodeling Beginning about 8 to 1 2 weeks after the injury, the Beginning about 8 to 1 2 weeks after the injury, the fracture site remodels itself, correcting any fracture site remodels itself, correcting any deformities that may remain as a result of the injury. deformities that may remain as a result of the injury. This final stage of fracture healing can last up to This final stage of fracture healing can last up to several years.several years.

The rate of healing and the ability to remodel a The rate of healing and the ability to remodel a fractured bone vary tremendously for each person fractured bone vary tremendously for each person and depend on: and depend on: age, health, the kind of fracture, and the bone involved. age, health, the kind of fracture, and the bone involved.

For example, children are able to heal and remodel their For example, children are able to heal and remodel their fractures much faster than adults.fractures much faster than adults.

Fracture HealedFracture Healed

Time Factor- Perkin’s Time Factor- Perkin’s formulaformula

Union Consolidation

Upper limb Spiral 3

Transverse 6

6 weeks

12 =

Lower Limb Spiral 6

Transverse 12

12 =

24 =Children Half this time is needed

Healing of fracturesHealing of fractures Factors disrupting Factors disrupting

healing process:healing process: Displaced and Displaced and

comminuted fracturescomminuted fractures InfectionInfection Vascular insufficiencyVascular insufficiency Inadequate minerals Inadequate minerals

and vitaminsand vitamins Inadequate Inadequate

immobilizationimmobilization

COMPLICATIONSCOMPLICATIONS Delayed union:Delayed union: A fracture  A fracture

that takes longer to heal than that takes longer to heal than expected is a delayed union.expected is a delayed union.

Nonunion:Nonunion: A fracture that  A fracture that fails to heal in a reasonable fails to heal in a reasonable amount of time is called a amount of time is called a nonunion (pseudarthrosis)nonunion (pseudarthrosis)

COMPLICATIONSCOMPLICATIONS

General:-General:- NutritionNutrition Bone DiseaseBone Disease Old AgeOld Age

Other Causes of Delayed Union & Non Union

Other Causes of Delayed Union & Non Union

COMPLICATIONSCOMPLICATIONSMalunionMalunion

Malunion: Malunion: A fracture A fracture that does not heal in a that does not heal in a normal alignment is normal alignment is called a malunioncalled a malunion

1- Primary Neglected #1- Primary Neglected # 2- After Reduction! 2- After Reduction!

WatchWatch

X-Ray After 10 DaysX-Ray After 10 Days

COMPLICATIONSCOMPLICATIONS

Compartment syndrome: Compartment syndrome: Severe swelling after a fracture can put Severe swelling after a fracture can put

so much pressure on the blood vessels so much pressure on the blood vessels that not enough blood can get to the that not enough blood can get to the muscles around the fracture. muscles around the fracture.

The decreased blood supply can cause The decreased blood supply can cause the muscles around the fracture to die, the muscles around the fracture to die, which can lead to long-term disability.which can lead to long-term disability.

Compartment syndrome usually occurs Compartment syndrome usually occurs only after a severe injury.only after a severe injury.

COMPLICATIONSCOMPLICATIONS  

Neurovascular injuryNeurovascular injury Infection:Infection: Open fractures can  Open fractures can

become infected become infected Post-traumatic arthritis:Post-traumatic arthritis: Fractures  Fractures

that extend into the joints (intra-that extend into the joints (intra-articular fractures) or fractures that articular fractures) or fractures that cause the bones to meet at an cause the bones to meet at an abnormal angle in the joint can cause abnormal angle in the joint can cause premature arthritis of a joint.premature arthritis of a joint.

COMPLICATIONSCOMPLICATIONS

Growth abnormalities:Growth abnormalities: A fracture  A fracture in the open physis, or growth plate, in the open physis, or growth plate, in a child, can cause many problems.in a child, can cause many problems.

Two of these problems are:Two of these problems are: premature partial or complete closure premature partial or complete closure

of the physis. This means that one side of the physis. This means that one side of a bone or the whole bone stops of a bone or the whole bone stops growing before it naturally would. growing before it naturally would.