Swollen Calf

Question 1

What are the main factors to consider when coming up with a differential diagnosis for calf swelling?

Answer 1

Is it acute or chronic?

Is it in one leg or both legs?

Question 2

Construct a differential diagnosis for a single acutely swollen calf.

Answer 2

Vascular:
DVT
Compartment syndrome

Knee joint:
Baker cyst
septic arthritis

Skin changes:
Cellulitis
Allergy insect bite

Muscle strain

Question 3

Construct a differential diagnosis for bilateral calf swelling.

Answer 3

Right heart failure 
Lymphoedema 
Venous insufficiency
Pregnancy
Vasodilators (e.g. CCBs)
Hypoalbuminaemia
Pelvic tumour

Question 4

List some key features of the history that you should ask the patient about.

Answer 4

Symptoms of PE
Cuts/wounds/insect bites on affected limb
Is the swelling getting any bigger?
Signs of pelvic malignancy (e.g. PR bleeding, unusual vaginal bleeding, abdominal pain)
Radiotherapy and surgery to affected leg

Question 5

List some risk factors for DVT.

Answer 5

Trauma 
Surgery
Bed rest
Long-haul travel
Cancer
Pregnancy
OCP and HRT

Question 6

List the main symptoms of PE.

Answer 6

Breathlessness
Pleuritic chest pain
Haemoptysis

Question 7

Which cause of calf swelling is associated with a rapidly growing swelling along the affected limb?

Answer 7

Cellulitis

Question 8

Why should you ask about symptoms of GI, ovarian and uterine malignancy (e.g. PR bleeding, unusual vaginal bleeding, weight loss)?

Answer 8

A pelvic mass (e.g. a tumour) could compress the iliac veins or IVC leading to leg swelling

Question 9

Why should you ask a patient about previous radiotherapy and surgery to the affected leg?

Answer 9

Increases risk of lymphedema

Question 10

List how, on examination, the nature of the swelling is different in:
Septic Arthritis
Compartment Syndrome
Baker’s Cyst

Answer 10

• Septic Arthritis
  Swelling around the joint
• Compartment Syndrome
  Swelling/inflammation is confined to the compartment but spares the joints
• Baker’s Cyst
  Swelling protrudes backwards from the knee joint into the popliteal fossa
  NOTE: rupture of the Baker’s cyst can make the swelling run down into the calf

Question 11

Why is it important to palpate for abdominal masses?

Answer 11

Abdominal masses could compress the IVC or iliac veins leading to leg swelling

Question 12

Why is it important to assess the neurovascular status of the affected limb?

Answer 12

The high pressure within the compartment in compartment syndrome can lead to compromise of neurovascular status

Question 13

Describe how the pain on passive movement is different in:
Septic Arthritis
Compartment Syndrome

Answer 13

• Septic Arthritis
  Pain in the joint
• Compartment Syndrome
  Pain in the calf

Question 14

Describe how the Wells’ score is interpreted.

Answer 14

< 4 = D-dimer to rule out PE

4+ = CTPA

Question 15

What the most sensitive, rapid and non-invasive method of visualising a DVT?

Answer 15

Doppler ultrasound of proximal leg veins

NOTE: this can also help distinguish DVTs from Baker’s cysts

Question 16

Why might FBC and Clotting Screen be useful in a patient with a swollen calf?

Answer 16

FBC – may show high WCC (infection), high RBC (polycythaemia –> hypercoagulability)
Deranged coagulation – increased risk of clots forming

Question 17

Outline the management of DVT.

Answer 17

Anticoagulation (with LMWH or fondaparinux, then ongoing anticoagulation is achieved with warfarin or rivaroxaban)
Compression stockings 
Lifestyle advice (e.g. stop HRT/COCP, lose weight)

Question 18

Describe the typical features of compartment syndrome.

Answer 18

Tense, shiny, swollen limb that is painful to passive movement

Question 19

What is the most common cause of compartment syndrome?

Answer 19

Trauma

Question 20

What can the high pressures within the compartment in compartment syndrome lead to?

Answer 20

Neurovascular compromise –> ischaemia and necrosis

Question 21

What can compartment syndrome of the anterior compartment of the forearm lead to?

Answer 21

Volkmann’s contracture – permanent flexion of the wrist due to ischaemia and necrosis of the anterior forearm compartment muscles

Question 22

How is acute compartment syndrome managed surgically?

Answer 22

Emergency fasciotomy

Question 23

Outline the management of cellulitis.

Answer 23

Antibiotics
Demarcation of erythematous region to monitor progress
Elevation – helps reduce the swelling and reduce pain
Topical steroids and oral antihistamines – in the case of an inflammatory reaction to an insect bite (may present similarly to cellulitis)

Question 24

What is a Baker’s cyst?

Answer 24

Swelling of a synovial bursa (usually the semimembranosus bursa) around the knee joint
NOTE: also known as a popliteal cyst

Question 25

Rupture of a Baker’s cyst can be clinically indistinguishable from which other cause of calf swelling?

Answer 25

DVT

Question 26

Outline the treatment of a ruptured Baker’s cyst.

Answer 26

Elevation of affected limb
Aspiration of fluid
Corticosteroid injection

Question 27

List some congenital mutations that cause hypercoagulability.

Answer 27

Factor V leiden
Antithrombin III deficiency
Protein C deficiency
Protein S deficiency

Question 28

List some diseases that cause hypercoagulability.

Answer 28

Any malignancy
DIC
Antiphospholipid syndrome
Polycythaemia

Question 29

List some drugs that cause hypercoagulability.

Answer 29

COCP
HRT
Procoagulant/antifibrinolytic drugs

Question 30

Describe the mechanism of action of warfarin.

Answer 30

Vitamin K epoxide reductase inhibitor
Inhibits the gamma-carboxylation of factors 2, 7, 9 and 10
Also inhibits the production of protein C and protein S (thus causing an transient hypercoagulable stage)
This is why warfarin is started with LMWH until the INR has remained within the target range for > 24 hrs

Question 31

List some contraindications for warfarin.

Answer 31

Pregnancy (teratogenic)
Severe hypertension (risk of haemorrhagic stroke)
Peptic ulcer disease

Question 32

Under what circumstance can a DVT lead to a stroke rather than a PE?

Answer 32

Patent foramen ovale (PFO)