Fracture And Dislocation

By Dr. KM Liau

Fracture

Dislocation

Subluxation

Fracture

A disruption in all or part of the cortex of a bone

All = complete

Part = incomplete = children

Picture: Complete fracture of the surgical neck of humerus

Dislocation

There is complete disruption of the joint.

Picture: Shoulder dislocation

Incomplete Fracture

Greenstick fracture - fracture through one cortex only (fracture in tension)

Incomplete Fracture

Torus fracture - Buckling of the cortex (fracture in compression

How are fracture desctibed?

1. By the direction of the fracture line

a) Transverse

b) Oblique

c) Longitudinal

d) Spiral

2. By the relationship of the fragments

a) Displacement

b) Angulation

c) Shortening

d) Rotation

3. By the number of fragments

a) Simple

b) Comminuted

4. By communication with the atmosphere

a) Closed fracture

b) Open fracture

Transverse Fracture

Frafture perpendicular to the long axis of the bone.

Caused by a force perpendicular to the shaft.

Oblique Fracture

Caused by a force usually applied in the same direction as the long axis of the bone.

Longitudinal fracture

Fracture along the long axis of the bone.

Spiral Fracture

A twisting fracture caused by a torque injury such as

planting the foot in a hole while running.

Displacement

By convention, abnormalities of position describe the relationship of the distal fracture fragment relative to the proximal fragment.

There is palmar displacement of the distal radius fracture fragment in this case.

Angulation

The angle away from the normal that the distal fragment makes with the proximal fragment.

In this case the distal fragment is angulated
medially from the position it would have were it not fractured.

Shortening

Overlapping of the ends of the fracture fragments.

Shortening is usually described by the number of centimeters of overlap.

Rotation

Almost always involves long bones (humerus and femur)

Knee joint is in AP position (points forward) but ankle points lateral, in this case.

Common Fracture Eponyms

1. Colle's fracture

2. Smith's fracture

3. Jones' fracture

4. Boxer's fracture

Colles' Fracture

It is named after Abraham Colles (1773-1843), an Irish surgeon who first described this in 1814 before the advent of X-rays.

It is a fracture of the distal radius with dorsal angulation occuring in elderly patients signifying underlying osteoporosis. (This term is not used in young adults - they are simply named distal end radius fracture)

Colles' Fracture

Extra-articular fracture of the distal radius

Does not extend into joint space

Dorsal angulation with radial and dorsal displacement of distal fragment

Frequently associated with fracture of ulnar styloid

Smith's fracture

This fracture is named after the orthopedic surgeon, Robert William Smith (1807-1873).

The distal fracture fragment is displaced volarly (ventrally), as opposed to a Colles' fracture which the fragment is displaced dorsally.

Jones' fracture

A Jones' fracture is a fracture of the base of the fifth metatarsal of the foot.

It was named after Sir Robert Jones, who in 1902, sustained this fracture while dancing around a maypole at a garden dance.

The injury is caused by stress plantarflexion and inversion.

Jones' Fracture

Jones' fracture often does not heal for several reasons.

1. This location is an area of poor blood supply. In medical terms it is a watershed area between two blood supplies.

2. In addition there are various tendons attaching in the area pulling the fracture apart causing motion at the site of healing.

Boxer's Fracture

A boxer's fracture, also known as the brawler's fracture, is the common name for a fracture at the neck of the fifth metacarpal bone.

These fractures are often angulated, and if severely so require pins to be put in place and realignment as well as the usual splinting.

However, the prognosis on these fractures is generally good, with total healing time not exceeding 12 weeks.

Easily Missed Fractures

1. Scaphoid fractures

2. Buckle fractures of radius/ulna

3. Radial head fracture

4. Supracondylar fractures in children

5. Posterior dislocation of the shoulder

6. Hip fractures

Scaphoid fractures

A scaphoid fracture is the most common type of wrist fracture.

Scaphoid fractures usually cause pain at the base of the thumb accompanied by swelling in the same area.

Tenderness in anatomical snuff box

Can lead to avascular necrosis

Buckle fractures of radius/ulna

Buckle fractures are common and result from axial loading on an extremity (ie, falling on an outstretched arm).

There are two types of buckle fractures: the classic buckle fracture, in which there is outward buckling of the cortex (Picture); and the angled buckle fracture, in which the cortex is merely angled.

In the classic buckle fracture, axial loading is almost pure and the resultant forces are distributed evenly across the metaphysis.

As a result, the trabeculae are crushed along the fracture line (sclerosis) and the cortices at either end bulge outwardly.

Angled Buckle Fracture

With the angled buckle fracture, in addition to axial loading, some other force (ie, varus, valgus, hyperextension or hyperflexion) is also at play.

This other force tends to lateralize the forces across the metaphysis.

Rather than an outward cortical buckling fracture occurring, an angled buckle fracture of the cortex occurs on one side.

Supracondylar fractures in children

It is the commonest elbow region injury and the peak age is 3 - 8 years.

In severe injury it presents as a swollen, painful deformity which is clinically similar to elbow dislocation.

Fat Pad Sign

It is very important to remember that this fracture may not be obvious radiographically except for the appearance of the posterior fat pad sign.

If this is positive then it should be assumed that there is an occult fracture.

Posterior dislocation of the shoulder

Humeral head looks like "lightbulb" - the lightbulb sign.

Usually need another view like axillary or Y-scapula view.

Hip fractures

May be very subtle and require bone scan or MRI for diagnosis.

In this case, white zone of sclerosis is an impacted subcapital fracture.