Coverage of Thigh Ian Maxwell. Gastocnemius Flap Mathes and Nahai type I muscle flap Indications – Most commonly upper third of leg defects and knee Exposed

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Coverage of Thigh Ian Maxwell Slide 2 Gastocnemius Flap Mathes and Nahai type I muscle flap Indications Most commonly upper third of leg defects and knee Exposed bone, tendon, metal Can be advanced on its pedicle as a V-Y for achilles coverage Can be used as a functional muscle free flap Lateral or medial heads can be taken Slide 3 Mathes and Nahai muscle flap classification Slide 4 Muscle Anatomy Origin: Lateral head: Lateral epicondyle of femur Medial head: Superior to medial epicondyle Posterior to insertion of adductor magnus Insertion Calcaneal epiphysis via achilles tendon Slide 5 Vascular Anatomy Medial head: Medial sural artery from popliteal artery (1cm proximal to knee joint) 4-5cm from origin of artery to muscle insertion Lateral head: Lateral Sural artery Pedicle length of 4cm (arises more distally) Venous drainage via venae comitantes Slide 6 Slide 7 Innervation Tibial nerve Slide 8 Flap dissection Midcalf longitudinal or straight incision beginning a few centimeters proximal to popliteal crease Sural vein and saphenous nerve retracted laterally Medial and lateral heads dissected in popliteal fossa and continued distally to achilles tendon Slide 9 Slide 10 Slide 11 Flap dissection Medial head is cut from Achilles tendon Dissect through loose areolar plane proximally between soleus and medial head of gastroc Dissect pedicle If necessary proximally divide origin Tunnel subcutaneously to defect Slide 12 Slide 13 Lateral head More difficult Common peroneal nerve at increased risk Shorter pedicle length Sometimes necessary of medial head flap cant reach defect Slide 14 Anterolateral thigh Flap A type B and C (septocutaneous and musculocutaneous perforators) fasciocutaneous flap Useful for local or distant defect reconstruction Flap size up to 8cm X 25cm with primary closure Indications: Free: anywhere Local: Thin flap, large surface area wounds Groin, knee, abdomen, trochanteric region Slide 15 Arterial Supply Lateral femoral circumflex artery Arises from lateral side of profunda femoris Runs obliquely in septum between vastis lateralis and rectus femoris Pedicle length is 12-16 cm For retrograde, distally based flaps can base it off of the lateral superior geniculate artery Slide 16 Slide 17 Venous drainage From venae comitantes accompanying artery Slide 18 Innervation Lateral femoral cutaneous nerve of thigh Can harvest as a sensate flap Slide 19 Flap elevation Mark ASIS and lateral patella This is the central axis of the flap Draw a circle of radius 3cm in the middle of the line This is where the perforators are Doppler them Base your flap around these perforators Slide 20 Flap dissection Dissect anteriorly first down to deep fascia Dissect subfascial anterior to posterior Vessels near or approaching the septum are preserved Dissect posterior to anterior Slide 21 Slide 22 Flap dissection If vessels are perforators are all septocutaneous then elevate on these If musculocutaeous then these must be dissescted out Follow pedicle proximally and ligate if free or preserve if pedicled If bulk is needed can preserve branches to VL or RF and take muscle with the flap Slide 23 References Microsurgeon.org Serafin, d. Atlas of microsurgical tissue transplantation Wei, Mardini. Flaps and reconstructive surgery