Lower limb Flashcards
What is the major blood supply to an ALT flap?
Descending branch of lateral femoral circumflex artery.
What are the branches of the profunda femoris?
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.
What does the popliteal artery bifurcate into?
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.
Describe the course of the posterior tibial artery
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.
Describe the course of the peroneal artery
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.
Which muscles are in the deep posterior compartment of the leg?
Popliteus
Flexor digitorum longus
Flexor hallucis longus
Tibialis posterior
What is the action of popliteus?
Lateral rotation of the femur relative to the tibia. This ‘unlocks’ the knee joint so that flexion can occur.
What type of flap is a medial plantar flap?
Fasciocutaneous
Describe the blood supply to the medial plantar flap
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.
Describe the modified Dunkin classification
I – Linear laceration without skin loss
II – Flap laceration (viable)
III – flap laceration non-viable
IV – skin loss
V – Laceration with haematoma
Name some indications for surgery in pretibial lacerations
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)
Which criteria are described in the Gustillo Anderson classification?
Wound size
Energy
Soft tissue coverage
Contamination
Periosteal stripping
Vascular injury
How would you perform a fasciotomy of the lower leg in compartment syndrome?
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.
Describe the steps in performing a lower limb fasciotomy
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
Define compartment syndrome
Acute compartment syndrome occurs when there is increased pressure within a closed osteofascial compartment, resulting in impaired local circulation.
