Lower limb

Question 1

What is the major blood supply to an ALT flap?

Answer 1

Descending branch of lateral femoral circumflex artery.

Question 1

What are the branches of the profunda femoris?

Answer 1

Perforating branches – Consists of three or four arteries that perforate the adductor magnus, contributing to the supply of the muscles in the medial and posterior thigh.

Lateral femoral circumflex artery – Wraps round the anterior, lateral side of the femur, supplying some of the muscles on the lateral aspect of the thigh.

Medial femoral circumflex artery – Wraps round the posterior side of the femur, supplying its neck and head. In a fracture of the femoral neck this artery can easily be damaged, and avascular necrosis of the femur head can occur.

Question 2

What does the popliteal artery bifurcate into?

Answer 2

At the lower border of the popliteus, the popliteal artery terminates by dividing into the anterior tibial artery and the tibioperoneal trunk. In turn, the tibioperoneal trunk bifurcates into the posterior tibial and fibular arteries.

Question 3

Describe the course of the posterior tibial artery

Answer 3

Continues inferiorly, along the surface of the deep posterior leg muscles (such as tibialis posterior). It enters the sole of the foot via the tarsal tunnel, accompanying the tibial nerve.

Question 4

Describe the course of the peroneal artery

Answer 4

Descends posteriorly to the fibula, within the posterior compartment of the leg. It gives rise to perforating branches, which penetrate the intermuscular septum to supply muscles in the lateral compartment of the leg.

Question 5

Which muscles are in the deep posterior compartment of the leg?

Answer 5

Popliteus
Flexor digitorum longus
Flexor hallucis longus
Tibialis posterior

Question 6

What is the action of popliteus?

Answer 6

Lateral rotation of the femur relative to the tibia. This ‘unlocks’ the knee joint so that flexion can occur.

Question 7

What type of flap is a medial plantar flap?

Answer 7

Fasciocutaneous

Question 8

Describe the blood supply to the medial plantar flap

Answer 8

Artery: medial plantar artery and perforator, derived from posterior tibial. Between abductor hallucis and flexor digitorum brevis.

Vein(s):
The subcutaneous venous system draining to the saphenous vein is usually used, since it is larger in caliber and much thicker walled.

Question 9

Describe the modified Dunkin classification

Answer 9

I – Linear laceration without skin loss
II – Flap laceration (viable)
III – flap laceration non-viable
IV – skin loss
V – Laceration with haematoma

Question 10

Name some indications for surgery in pretibial lacerations

Answer 10

Large necrotic skin flaps
Large area of skin loss
Major haematoma
Failure of Cx management after 2-3 months
Gross contamination/infection – may require debridement/grafting
Wound size alone not necessarily an indicator (although sensible approach - >1% consider)

Question 11

Which criteria are described in the Gustillo Anderson classification?

Answer 11

Wound size
Energy
Soft tissue coverage
Contamination
Periosteal stripping
Vascular injury

Question 12

How would you perform a fasciotomy of the lower leg in compartment syndrome?

Answer 12

A 15 cm longitudinal incision between the fibula and tibial crest, and a 2nd longitudinal incision 2cm posterior to the medial margin of the tibia.

In accordance with BOAST/BAPRAS guidelines.

Question 13

Describe the steps in performing a lower limb fasciotomy

Answer 13

Double incision or single incision technique – double incision is the UK standards
Medial incision: 1cm medial to medial cutaneous border of tibia 15-20cms
Releases both posterior compartments
Tibial attachment of soleus needs to be released to access deep posterior compartment

Lateral incision: 2cm lateral to lateral cutaneous border of tibia 15-20cms
Releases anterior and lateral compartment
In closed injuries, this incision can be more lateral over the anterolateral intermuscular septum, as there is no need to preserve perforators.

Divide intermuscular septum through subfacial dissection laterally from anterior compartment.

Following decompression evaluate muscle: colour, contractility, consistency and capacity to bleed

Question 14

Define compartment syndrome

Answer 14

Acute compartment syndrome occurs when there is increased pressure within a closed osteofascial compartment, resulting in impaired local circulation.

Question 15

What are the guidelines for timing of wound excision in open fractures?

Answer 15

1. Broad-spectrum antibiotics (co-amoxiclav 1.2 g 8 hourly or cefuroxime 1.5 g
   8 hourly or clindamycin 600 mg 6 hourly if anaphylaxis to penicillin) are administered as soon after the injury as possible (see Chapter 3).
2. The only reasons for immediate surgical exploration are the presence of:
   (a) Gross contamination of the wound
   (b) Compartment syndrome
   (c) A devascularized limb
   (d) A multiply injured patient.
3. In the absence of these criteria, the wound, soft tissue and bone excision (debride­ment) is performed by senior plastic and orthopaedic surgeons working
   together on scheduled trauma operating lists within normal working hours and within 24 hours of the injury unless there is marine, agricultural or sewage