Joints and Fractures

What is a dislocation?

when a joint is not aligned properly

What is a luxation?

A dislocation in which the articulating surfaces of

a joint are forced entirely out of position

What is a subluxation?

Damage to a joint so that it is slightly out of its

normal position

What is ankylosis?

stiffness in a joint, due to rigidity from injury or

disease. A surgeon repairing a damaged joint must be

certain to maintain the shape of the articulating

surfaces, because incorrectly apposed articulating

surfaces might develop abnormal ankyloses. Most

joints have surfaces that match. If an injury occurs

and the joint surfaces no longer match, bone spurs

may form. The joint cannot alter its shape to adapt

Which fracture is the most serious?

Which is the least serious?

 COMMINUTED

 STRESS

Define Comminuted fracture

bone shatters into many small

pieces (at least 3). Bone graft might be needed.

Define Spiral fracture

Bone was twisted, such as in skiing or

rollerblading.

Define Greenstick fracture? Which is most common in children?

breaks on one side, bowstrings on

other. Most common in children; like breaking

a green twig, it’s not completely broken.

Bones in children are not fully mineralized.

Which is most common in children?

Greenstick: Breaks on one side, bowstrings on

other. Most common in children; like breaking

a green twig, it’s not completely broken.

Bones in children are not fully mineralized.

What is an epiphyseal fracture?

break occurs across epiphyseal

plate; usually causes the bone to grow

crooked.

What fractures are ONLY seen in

children?

Epiphyseal and greenstick fractures are only

seen in children

What fracture is the least serious?

Describe.

Stress fracture: tiny, almost invisible breaks

on outer surface on shaft/bone. Usually from

overexertion. Muscle builds up faster than

bone. Six weeks into military basic training

camp, see lots of stress fractures from too

much new running.

What type of fracture is when the bone

does not break through the skin?

Simple (closed) fracture

What type of fracture is when the bone

breaks through the skin?

Compound (open) fracture: Bone breaks and goes

through skin. Increased chance of infections,

which can be life-threatening.

Which fractures require hospitalization

with IV antibiotics?

Compound (open)

What is a displaced fracture?

Produces new and abnormal bone arrangements

Define PATHOLOGICAL

FRACTURE

When the bone (especially

the hip bone of someone with osteoporosis)

breaks first, then the patient falls.

What is a Colles’ fracture?

fracture of the distal radius in the forearm with

dorsal (posterior) displacement of the wrist and

hand. The fracture is sometimes referred to as a

"dinner fork" or "bayonet" deformity due to the

shape of the resultant forearm. Often occurs when

a runner falls on their outstretched hands

When does a pisiform fracture occur?

in a fall on the outstretched hand with the wrist in

extension or if the heel of the hand is used like a

hammer

Why is a pisiform fracture significant?

The bone may need to be removed surgically, and

being an anchor for several ligaments and

muscles, when one fractures the pisiform, there is

a 50% chance of additional fractures in the distal

radius or another carpal bone.

What is the cause of a scaphoid fracture

and why it is significant?

They frequently occur following a fall onto an

outstretched hand. Scaphoid fractures are among

the most common injuries. X-rays taken soon

after the injury may not reveal a fracture, but

diagnosis needs to be made quickly to prevent

death of this bone. Scaphoid fractures account

for 60-70% of all carpal fractures

What is the anatomical snuffbox?

The anatomical snuffbox is a triangular deepening

on the radial, dorsal aspect of the hand—at the

level of the carpal bones, specifically, the

scaphoid and trapezium bones forming the floor

Why is the anatomical snuffbox

significant?

In the event of a fall onto an outstretched hand,

this is the area through which the brunt of the

force will focus. This results in the scaphoid bone

being the most often fractured of the wrist.

The scaphoid is a small, oddly shaped bone whose

purpose is to facilitate mobility rather than confer

stability to the wrist joint, so it is often the weak

link. Interestingly, scaphoid fracture is one of the

most frequent causes of medico-legal issues.

What is osteochondritis dessicans?

When a bone dies from lack of blood supply

Why is a scaphoid fracture often

associated with osteochondritis

dessicans?

An interesting anatomical anomaly in the

vascular supply to the scaphoid is that blood

enters the scaphoid distally.

In the event of a fracture, the proximal segment

of the scaphoid will be devoid of a vascular

supply, and avascular necrosis (death of tissue

from lack of blood supply) will occur if action is

not taken. Due to the small size of the scaphoid

and its shape, it is difficult to determine, early on,

whether or not the scaphoid is indeed fractured

with an x-ray. Pain in the anatomical snuffbox is

a presumptive diagnosis of a fracture. The patient

would then be sent to get an MRI

What is a transverse fracture?

Bone breaks from right to left in the transverse

plane

What is an oblique fracture?

Bone breaks from top right to bottom left (or vice-

versa).

What is an avulsion fracture?

A strong muscle contraction pulls a piece of bone

off where the muscle attaches to that bone.

Example is a groin injury with avulsion fracture

What is an impacted fracture?

Pressure was exerted on both ends of the SAME

bone. Often seen in the femur after falling from a

height.

Define COMPRESSION fracture

TWO bones are forced together,

and bone is crushed, like the vertebrae in

osteoporosis.

What is a depression fracture?

When a blunt object crushes a bone, depressing it,

such as skull fracture

What is the difference between a

fibrous joint and a fibrocartilage joint?

FIBROUS JOINTS

Are connected by fibrous connective tissue (not

cartilage)

FIBROCARTILAGE JOINTS

Are connected by fibrocartilage (not connective

tissue)

Which fibrous joints are immovable?

What movement classification are they?

Sutures and gomphosis

They are synarthrotic (immoveable)

Which fibrous joints are moveable?

What movement classification are they?

Syndesmosis (ligament)

It is amphiarthrotic (slightly movable)

What type of tissue is found in a

syndesmosis?

Fibrous connective tissue

What type of joint classification

permits only slight degrees of

movement (partially movable)?

Amphiarthrotic

What are the two types of

CARTILAGINOUS JOINTS? What

type of movement do they allow?

Fibrocartilage- amphiarthrotic ( a little movement)

Hyaline cartilage- synarthrotic (no movement)

What are the two examples of

fibrocartilage joints in the classification

of Cartilaginous Joints?

Vertebral discs amphiarthrotic ( a little

movement)

Pubic symphysis amphiarthrotic ( a little

movement)

What are the two examples of hyaline

cartilage joints, in the classification of

Cartilaginous Joints?

Epiphyseal plate,which is synarthrotic (no

movement)

Costal cartilage, which is synarthrotic (no

movement)

SYNCHONDROSIS

 How much movement is

present?

 Give an example

 No movement (Synarthrotic)

 Example is epiphyseal plate (growth plates in

children).

What type of tissue is found in a

synchondrosis?

Hyaline cartilage

Define SYMPHYSIS

 How much movement is present?

 Give two examples

 Fibrocartilage, between bones.

 Moves a little (amphiarthrotic)

 Examples are pubic symphysis and

intervertebral discs

What joints are classified as having no

movement?

Suture (between skull bones), gomphosis

(tooth socket), and synchondrosis (epiphyseal

plate).

What are the outer and inner areas of an

intervertebral disc called

 What kind of cartilage is each area

made of?

 Outer ring of fibrocartilage called the

ANNULUS FIBROSIS

 Inner area of elastic cartilage called the

NUCLEUS PULPOSIS

What is the most common structure of

joint?

 How much movement is present?

 Where are these joints found?

 Synovial joints are the most common type of

joint

 They are highly moveable.

 Almost every joint you think about is this

type (elbows, knees, hips, fingers)

What is the main thing that stabilizes

the hip joint?

 What type of cartilage is at the ends

of long bones?

 The ligaments around the head of the femur

(not the little one on the fovea capitis).

 hyaline cartilage

What are the abbreviations for the

finger and toe joints?

 MPJ: Metacarpal phalangeal joints (fingers) or

metatarsal phalangeal joints (toes).

 IPJ: Interphalangeal joints (knuckles of fingers

and toes)

 There are two types of IPJ’s

DIPJ: distal knuckles

PIPJ: proximal knuckles

 The thumb (pollex) and big toe (hallux)

knuckle is just called its IPJ, but the knuckles

of the other digits are identified specifically as

a DIPJ or PIPJ

What lines the inside of the joint

capsule?

 What is its function?

 SYNOVIAL MEMBRANE, which makes

SYNOVIAL FLUID

What are the 2 functions of

SYNOVIAL FLUID?

 Function 1: Lubricates the joint, allows

smooth movement. Its viscosity (thickness)

changes with pressure, so that bones will

never touch, even when you jump up and

down (just thickens up).

 Function 2: Nourishes articular cartilage

(which is Avascular [no blood supply]).

Every movement puts pressure on joint,

forcing fluid into cartilage. Therefore, you

need pressure on joints to feed the cartilage

What is a ligament?

connect bone to bone

What are ligaments made out of?

Made of dense regular connective tissue (NOT

Muscle Tissue).

Why do ligaments take a long time to

heal if torn?

Take a long time to heal because they do not

have blood vessels of their own, like bones do.

They already have enough fibroblasts and

collagen, though, so they eventually can heal.

What is a tear in a ligament called?

 What is a tear in a muscle called?

 What will heal faster – a sprain or

strain?

 A torn ligament is a sprain.

 A torn muscle is a strain

 A strain will heal faster because it has a better

blood supply

What are MENISCI and what type of

tissue are they?

 Fibrocartilage

 Menisci are fibrocartilage pads in some joints

(knee). Acts as a guide for movement of joints

to prevent unwanted movement such as lateral

movement in the knee. (Common injury).

However, they are NOT the structures that are

the most important in keeping the knee from

moving. The collateral ligaments are.

Ligaments outside a joint capsule are called

what? Give examples.

 Extracapsular.

 Patellar ligament (patellar tendon)

 Medial collateral ligament

 Lateral collateral ligament

Ligaments inside a joint capsule are

called what? Give examples.

Intracapsular: Anterior and posterior cruciate

ligaments

In the knee joint, what structures are

MOST important in keeping the knee

from moving medially to laterally?

The collateral ligaments

Define BURSA and its function

A bursa is a sack of synovial fluid that does

not need to be attached to any bone. It has a

synovial membrane, and involved in

lubrication between a muscle/ligament or

tendon/bone, etc

What’s an inflamed bursa called?

Bursitis

Name the 6 TYPES OF SYNOVIAL

JOINTS, characterized by types of

movement

 Give examples of each.

1. PLANE (GLIDING) JOINTS: like the

royal wave of the hand; carpals slide past

each other.

2. HINGE JOINTS: one plane; knee, elbow,

phalangeal joints

3. PIVOT

4. CONDYLOID

5. SADDLE

6. BALL AND SOCKET JOINTS: shoulder,

hip; lots of mobility.

What is a plane joint?

Movement in only one plane: transverse or

frontal plane.

Examples: The carpal and tarsal bones, between

the articular processes of the vertebrae, and at the

sternoclavicular joint

What is a hinge joint?

Movement in only one plane: sagittal plane.

Examples:

The elbow, knee, and IPJ = interphalangeal

(finger and toe) joints

What is a pivot joint?

Allows only rotational movements, and the

rotational movement is in only one plane:

transverse plane. The joint between the first two

vertebrae and proximal radioulnar joint, where

the annular ligament on the ulna encircles the

head of the radius

What is a condyloid joint?

Movement in two planes (biaxial)

Example: Metacarpal-phalangeal joints (MPJ’s):

these are biaxial condyloid joints

What is a saddle joint?

Movement in two planes (biaxial)

Each joint surface is both convex in one plane

and concave in the other. They fit together like a

rider on a saddle. Examples are at the base of the

thumb (between the trapezium and metacarpal I).

Saddle joints are biaxial joints; in primate

anatomy, allows for the opposable thumb

What is a ball and socket joint?

Movement in all three planes

Shoulder and hip joints are ball and socket. This

type of joint is multiaxial.

Name the 3 Types of ARTHRITIS

we discussed

ARTHRITIS: (“itis” means inflammation; “artho”

means joint).

1. OSTEOARTHRITIS

2. RHEUMATOID ARTHRITIS

3. GOUTY ARTHRITIS

What is osteoarthritis?

A chronic disorder of joints in which the articular

cartilages degenerate and bony spurs form

69. Which type of arthritis is characterized

by bone spurs?

70. What is known as “wear and tear”

arthritis?

71. What is the most common disorder of

joints?

OSTEOARTHRITIS

What causes RHEUMATOID

ARTHRITIS?

Is it characterized by bone spurs

(proliferative in nature) or is it degenerative

in nature?

RA is not a disease of old age. It’s an

autoimmune disease where body attacks and

destroys the cartilage in synovial joints.

 It does NOT make many bone spurs; it is

degenerative in nature

What causes GOUTY ARTHRITIS

(gout).

 What triggers it?

 What is the process where gout

leads to pain?

 Is gout known for producing bone

spurs?

Gout is a genetic error in the metabolism of uric

acid.

An episode is triggered by eating too much red

meat or protein.

The breakdown product of proteins is urea, which

leads to uric acid crystals in the cooler areas of the

body, especially the MPJ’s (metatarsal-phalengeal

joints) of the base of the big toes. The crystals

poke the cartilage like needles.

**Gout is not known for spur formation, unlike

osteoarthritis.

What is Osteomalacia?

Osteomalacia (“malformed bones”; Osteo= bone;

mal=bone) a genetic malformation of the bones.

How do children get Rickets ?

Rickets is a type of osteomalacia caused by lack

of vitamin D (not genetic).

What part of children’s bones are

affected by osteomalacia?

All types of Osteomalacia particularly affect the

epiphyseal plates (children).

Define Osteomyelitis

Osteomyelitis is a BACTERIAL infection of

bone. (Not a viral infection)

Define Achondroplasia

Achondroplasia is a genetic condition where the

bones don’t develop properly and causes a type of

dwarfism. The epiphyseal plates are affected

Define Chondromalacia

Chondromalacia is a condition in which the

patella rubs on the femur in the knee joint.

What are the three characteristics of

Paget’s disease

excessive bone deposition (extra bone forms

outside of joint)more common in older persons,

and may be related to a viral infection.

What type of arthritic disease has several

features, including the binding together of

the vertebrae, limiting the flexibility

spine?

Ankylosing Spondylitis

What’s the difference between Ankylosis

and Ankylosing spondylitis?

Ankylosis is when bone spurs connect the

vertebrae. Ankylosing Spondylitis is a syndrome

that includes Ankylosis and several other features.

What arthritis can result from a

bacterial infection after a tic bite?

Lyme disease

Define Synovitis

 Define Arthroplasty

Synovitis is the inflammation of the synovial

tissues. May need cortisone injections.

Arthroplasty is a surgical procedure to repair or

remodel a damaged joint.