Session 11: Common Fractures

What process occurs during secondary bone healing?

• ENDOCHONDRAL OSSIFICATION
  Soft callus (fibrocartilaginous) forms around the fracture, bridging the gap.

• This gradually gets replaced by hard callus (woven bone) through endochondral ossification.

Which late fracture complication is shown in this X-ray?

Malunion

Late fracture complications

Delayed union

Fracture healing takes twice as long as expected for specific location

Non-union

Fracture healing does not occur within 6-9 months

Malunion

Healing in a non-anatomical position

Most common fracture of long bones

Diaphyseal fractures of the tibia

Anatomy of a long bone

Tibial shaft fracture

Caused by high-energy direct force e.g., fall from height

+/- severe soft tissue injury and compartment syndrome

Can also be caused by low-energy trauma e.g., indirect twisting injury > spiral fracture pattern (image)

Compartment syndrome

Increased pressure in a closed fascial compartment, usually secondary to trauma

Causes

- Trauma

- Crush injury/fracture

- Most commonly tibial fracture

- Other: vascular injury, tight casts, DVT

Pathophysiology

- Fascial compartments have a fixed volume

- Adding fluid to the compartment e.g., blood, exudate - increase pressure

- If compartment pressure > capillary pressure = ischemia

Clinical Features

- Severe pain which is out of proportion to injury

- Tense compartment

- If it progresses = 5 P's of acute ischemia

The 5 P's of acute ischemia (compartment syndrome features)

Pain

Pallor

Perishingly cold

Paralysis

Pulselessness (late sign)

Management of compartment syndrome

Fasciotomy

Neck of femur fractures

Causes

- Low energy injuries in frail patients e.g., osteoporosis (fragility fractures)

- High energy injuries in young patients e.g., RTC

- Pathological fractures (in bone with tumour/infection)

Classification

- Extracapsular = between greater & lesser trochanter

- Intracapsular = below lesser trochanter

How would you classify this fracture (right)

Intracapsular neck of femur fracture

*Note: shenton's line is not smooth as it should be (left image)

How would you classify this fracture?

Extracapsular neck of femur fracture (intertrochanteric)

Why are neck of femur (intracapsular) fractures dangerous?

Majority of blood supply is retrograde (lateral and medial circumflex arteries)

An intracapsular fracture may disrupt the retrograde blood supply > risk of avascular necrosis to the femoral head

Tx intracapsular fractures of the femur

Hemiarthroplasty

Total hip replacement

Tx extracapsular fractures of the femur

Dynamic hip screw

Intramedullary nail

Danis-Webber classification for ankle fractures (based on lateral malleolus)

Type A = below syndesmosis

Type B = at the level of the syndesmosis

Type C = above the syndesmosis

*The syndesmosis is a fibrous joint held together by ligaments near the ankle joint

According to the Danis-Webber classification - what type of ankle fracture does this x-ray show?

Type A

Below syndesmosis

According to the Danis-Webber classification - what type of ankle fracture does this x-ray show?

Type B

At the level of the syndesmosis

According to the Danis-Webber classification - what type of ankle fracture does this x-ray show?

Type C

Above the syndesmosis

Distal radius fractures and causes

Colle's fracture and Smith's fracture

Most common orthopaedic fracture

- Low energy injuries in older patients e.g., FOOSH

- High-energy injuries in young patients e.g., RTC

- Pathological fractures (in bone with tumour/infection)

Colle's fracture

Extra-articular fracture of the distal radius

Dorsal angulation & dorsal displacement - dinner fork deformity

Caused by FOOSH to the FRONT of the hand

Smith's fracture

Extra-articular fracture of the distal radius

Volar angulation +/- volar displacement - garden spade deformity

Caused by FOOSH to the BACK of the hand

What is the most commonly fractured carpal bone?

Scaphoid bone

Scaphoid fracture

Most commonly fractured carpal bone

Presents with pain, tenderness of anatomical snuffbox, pain on axial loading on thumb

Caused by FOOSH

80% of scaphoid blood supply is retrograde through ___ ___ ___. Therefore, proximal fractures are at higher risk of avascular necrosis.

80% of scaphoid blood supply is retrograde through dorsal carpal branch. Therefore, proximal fractures are at higher risk of avascular necrosis.

Humerus fracture

MOI:

High-energy trauma

- Young people

- Soft tissue/neurovascular injury

Low-energy trauma

- Older people

- Falls

The surgical neck of humerus is more frequently fractured than the anatomical neck

A fracture at the surgical neck of the humerus will most likely damage what nerve?

Axillary nerve

A fracture at the medial epicondyle of the humerus will most likely damage what nerve?

Ulnar nerve

A supracondylar fracture of the humerus will most likely damage what nerve?

Median nerve

A midshaft fracture of the humerus will most likely damage what nerve?

Potential damage to radial nerve

What fracture is observed in this x-ray image?

Radius fracture

Match A, B, C, and D with the following options.

A → small head of biceps femoris

B → Common peroneal nerve

C → Popliteus muscle

D → Sciatic nerve

What is A and B?

A is a dermatome map

B is a cutaneous area nerve map

If you have complete numbness in one of the shaded areas in the image labelled ___, this likely points to a peripheral nerve being damaged and would likely include sensory and motor loss.

If you have complete numbness in one of the shaded areas in the image labelled B, this likely points to a peripheral nerve being damaged and would likely include sensory and motor loss.

You have a patient come into your office with an abnormal gait.

When they stand on their left leg with their right leg up in the air, their right hip drops below the level of his left hip. What type of gait would this present as?

Trendelenburg gait

Which nerve emerges superficial to the sartorius muscle and if compressed can result in Meralgia Paresthetica AND how might this compression present in a patient?

Lateral cutaneous nerve of the thigh - numbness in the lateral thigh

A 37 year old man was in a motorcycle accident and you are examining his injured ankle. You see his x-ray below.

What fracture do you see?

Medial malleolar fracture

Normally, when you consider inversion and eversion movements at your ankle, you have a greater range of movement when inverting your ankle.

Why is this?

Movements take place at the subtalar joints and the bony fibula on the lateral side of the ankle extends more inferiorly when compared to the medial distal end of the bony tibia, which prevents much eversion to occur

What important nerve and artery can be found in the tarsal tunnel & WHERE is this tunnel located?

Posterior tibial artery and tibial nerve can be found in the tarsal tunnel.

The tarsal tunnel passes posteriorly between the medial malleolus and calcaneus.

Label A-D

A = Femur lower end

B = Tibial tuberosity

C = Intercondylar eminence

D = Joint cavity/space

Identify labels A-D

A = Medial malleolus

B = Distal tibiofibular joint

C = Talus

D = Calcaneus

The label A represents ___ ___ muscle. It acts on ___ joint and moves the foot into the position of ___ movement of the foot. The B represents the heel bone called ___.

The label A represents peroneus longus muscle. It acts on subtalar joint and moves the foot into the position of eversion movement of the foot. The B represents the heel bone called calcaneus.

In the image below...

1) The site labelled A is a palpable landmark called ___

2) The ligament that attaches to site marked B is called ___

1) Tibial tuberosity

2) Medial collateral ligament

Sesamoid bones are found embedded in ________.

Tendons

*Think of the patella!

Four muscles that plantarflex the foot?

Flexor digitorum longus

Gastrocnemius

Soleus

Tibialis posterior

A car strikes a pedestrian on the lateral side of the leg at approximately the level of fibular neck; which nerve is most likely to be adversely damaged by such an injury

Common peroneal nerve

In an accident involving farm machinery, a farmer receives a cut on the dorsal side of his ankle. As you inspect and test for functional deficits, you find that a few tendons have been cut, but the accompanying nerve is intact. You would expect to find loss / weakness of...

Dorsiflexion of the foot

Which one of the following represents a clinical condition referred to as ‘water on the knee’?

Prepatellar bursitis

Which one of the following location / area does not need / have a bursa?

a) Around blood vessels

b) Tendons exposed to friction

c) Cartilage exposed to wear

d) Ligaments exposed to friction

e) Beneath skin covering a bone

a) Around blood vessels