Lower Extremity

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  • Anterior: Tibialis anterior, EDL, EHL 
  • Anterior tibial artery runs with deep peroneal nerve in anterior compartment (first web space numbness) 
  • Superficial Posterior: Gastrocnemius, soleus, plantaris 
  • Deep Posterior: FHL, FDL, Tibialis posterior 
  • Plantar surface by tibial nerve which travels in posterior compartment 
  • Posterior tibial vessels 
  • Lateral: peroneal muscle (longus and brevis) 
  • Superficial peroneal nerve in lateral compartment 
  • Absence of plantaris- 10-15%, more likely to be absent in LLE 


  • Compartments: Anterior, posterior, medial 
  • Layers: epidermis, dermis, two layers of fat, colles fascia 
  • Colles attaches to ischiopubic rami, scarpas fascia, perineum/medial thigh junction 


  • Periosteal vessels run transverse (so stay intact with transverse fractures) to supply the outer third of the cortex 
  • Metaphyseal vessels run longitudinal so are disrupted in most transverse fractures 
  • ankle-brachial indexes or toe-brachial indexes (used to assess perfusion of LE) 
  • toe >0.7 is normal 
  • ankle <0.9 = PAD, <0.70 = wound healing problems, <0.5 = rest pain 
  • ABI <0.7 predicts wound healing abnormalities post-operatively 
  • Base of arterial ulcer does not bleed and as punched out appearance; ulcers associated with ABI <0.45 do not heal without revascularization 
  • higher in calcified vessels 
  • Toe pressures <30mmHg indicates ischemia and need to obtain angiogram prior to soft tissue reconstruction (ABI can be misleading) 
  • To reach posterior tib vessels- between medial mal and achilles 
  • Lateral calcaneal artery is branch of peroneal artery (fibula, tarsus, calcaneal) 
  • Dorsalis pedis between tib ant and EHL 
  • Greater saphenous vein between medial mal and EHL 
  • Evaluation of vascular status (anatomy) 
  • Angiography- may use IV saline to prevent contrast induced nephropathy 
  • CTA- can be used after reduction/fixation if patients have warm but pulseless extremities 
  • Venous stasis ulcers- reveal edema, hemosiderin deposition, clean shallow and painful ulcers 
  • First line treatment is compression (unna boots) and elevation 
  • Venous thrombosis 
  • phlegmasia cerulea dolens – painful blue edema associated with critical illness or unretrieved IVC filters –> catheter directed thrombolysis 
  • Lack of treatment may lead to vascular insufficiency of LE and gangrene 
  • Open techniques like thrombectomy may be used in those with high bleeding risk 


  • Common peroneal (femoral) – injury leads to foot drop 
  • Common peroneal nerve lies between the biceps femoris and gastroc (courses around fibular neck 
  • Superficial peroneal – lateral leg sensation, peroneus longus, brevis (eversion) 
  • Deep peroneal – tib ant, EHL, EDL/B, peroneus, sensory to first web space (dorsiflexion) 
  • Common peroneal nerve compression: most common compression syndrome in lower extremity- usually by knee dislocations weakness of anterior compartment muscles and paresthesia of superolateral foot 
  • Superficial peroneal nerve compression from ankle reduction 
  • ankle arthroscopy the risk of SPN injury is maximal in the 0 to 3 mm lateral to the peroneus tertius tendon with antero lateral port placement 
  • Sural – sensation to lateral foot 
  • Sural nerve anatomy: 1cm posterior to lateral mal between lateral mal and achilles; purely sensory with contributions form medial sural nerve and lateral sural nerve (from tibial and peroneal respectively), can provide 30 cm of nerve graft (lateral foot sensation) 
  • Lateral calcaneal – cutaenous lateral heel skin 
  • Tibial – gastroc, soleus, plantaris, popliteus; FDL, TP, FHL; medial and lateral plantar nerves (plantarflexion) 
  • Plantar sensation 
  • Risk of tibial nerve in harvest, incision anterior or medial to achilles tendon (tom dick and nervous harry from anterior to posterior) 
  • Lateral plantar – quadratus plantae, ADM; sensory to skin of fifth toe and lateral fourth toe, foot intrinsics 
  • Medial plantar – instep sensation 
  • Tarsal tunnel syndrome: compression of medial plantar nerve to flexor digitorum brevis muscle and difficulty flexing toes, numbness after standing 
  • femoral – anterior thigh quads (leg extension) 
  • obturator – adductors, cutaenous sensation middle thigh (adduction) 
  • Sciatic nerve –> gastroc/soleus/plantaris/popliteous –> tibial nerve FDL/TP, FHL –> medial and lateral plantar nerves sensation to plantar surface of foot 



Injury scoring 


Gustillo = 

  • I – clean, wound <1cm 
  • II – contaminated, wound >1cm; no flaps or avulasions 
  • IIIA – contaminated, dusted bone, wound <10cm; segmental fractures etc 
  • IIIB – contaminated, dusted, >10cm req tissue coverage 
  • IIIC – vascular repair needed 

 Compartment syndrome 

  • compartment pressure >30mmHg or difference between compartment pressure and diastolic <20-30–> fasciotomy 
  • Can present after crush injuries 
  • Remember 5 Ps: pain, pallor, paresthesia, pulselessness,  
  • Antibiotic guidelines for LE fractures: 
  • For Grade I and II open fractures, a first-generation cephalosporin (eg, cefazolin) should be administered within 3 hours of initial injury and be continued for 24 hours after initial injury. Grade III open fractures require coverage with an aminoglycoside in addition to a first-generation cephalosporin within 3 hours of initial injury, and antibiotics should be continued for 48–72 hours after initial injury but no more than 24 hours after wound closure. If a fracture is at risk of contamination with clostridium species, such as a farm-related injury, penicillin should be added to the antibiotic regimen. 
  • Ex-fix best option for initial fracture stabilization due to need for multiple debridements 


  • In patients with ongoing wounds after ORIF, consider debridement prior to reconstruction given risk of NU and osteomyelitis 
  • MRI best imaging modality for osteomyelitis 
  • Internal fixation not associated with osteomyelitis in gustillo IIIB fractures 
  • Purulent drainage after open tib fib –> osteo –> debridement of bone (prevention measures include removal of dead space and devitalized bone, coverage with vascularized tissue) 
  • Low pressure lavage for tibial infection use surgical soap for preservation of osteoblast and osteoclastic function 
  • Calcaneous most common site for osteo of foot 


  • Contraindications for lower extremity replantation include crush mechanism of injury, ischemia time over 8 hours, multiple-level injury, poor baseline health, and a patient of advanced age 
  • TMA for necrosis of toes 
  • Tibial prosthetics are better fitting than ankle prosthetics  

Reconstruction (general principles and flaps) 

  • Total contact casting can be performed in patients with clean, slow healing wounds 
  • Heavily contaminated wound with no tissue loss –> serial debridements with delayed closure 
  • Bone grafting is done after soft tissue coverage 
  • Long standing wounds should be biopsied first to rule out Marjolin’s ulcer 
  • Ideal timing: within 72 hours, delay 72-90 days worst outcomes 
  • Thigh: 
  • Groin wounds: sartorious flap (perforators from SFA) 
  • Other options include gracilis, rectus femoris, vastus lateralis, TFL, rectus abdominus 


  • Pedicle: MCFA form profundus 

Posterior thigh 

  • Pedicle: inferior gluteal artery 
  • structure: fasciocutaneous – VY, or superiorly based tongue flap 
  • severs all connections from semitendinosus/semimembranosus/biceps femoris to skin so cannot use any of those as musculocutaneous flaps 


  • Pedicle: LFCA (descending branch) (perforates vastus lateralis) 
  • Innervation: lateral cutaneous nerve of thigh 
  • May be taken with vastus lateralis (may cause weakness in knee extension) 

Choice in soft tissue reconstructive options 

  • primary closure, secondary intention, skin graft if able 
  • biologic matrix for non flap candidates or small areas 
  • local flaps for less OR time, usually the preferable option especially in upper or medial third 
  • contraindicated if the flap or pedicle is within the zone of injury 
  • free flaps generally for lower third 
  • contraindications in the zone of injury, patient not a flap candidate 
  • can go end to side if there is single vessel runoff 
  • best when performed within 72h of injury, but must debride sufficiently and remove all nonviable tissue/foreign material 
  • muscle fills dead space better, but fasciocutaneous has less donor site morbidity 

Upper third 


  • Pedicle: medial & lateral sural artery and vein (off popliteal) 
  • Innervation: posterior tibial nerve (separate branches) 
  • Lateral gastroc: can injure common peroneal nerve — get foot paresthesias and foot drop 
  • Medial head of gastrocnemius: broader and larger belly than the lateral head, reaches farther 
  • Causes weakness in plantar flexion 
  • Bipedicled tibialis anterior: 
  • important for dorsiflexion – should not be sacrificed if can be avoided  
  • some function preserved when raised as a bipedicled flap 
  • Distal based ALT or vests laterals, or median geniculate 

Middle third 


  • Soleus muscle: (bipenniform) medial head from posterior tibia (posterior tib artery), lateral head from proximal fibula (peroneal); within superficial posterior compartment 
  • Indications: middle third defects 
  • Proximal soleus by popliteal artery/peroneal 
  • Proximally based soleus: can be carried to a point 5cm proximal to its tendinous insertion 
  • Reverse soleus from posterior tib (for more distal defects) 
  • Soleus has perforators from popliteal, peroneal, posterior tibial 
  • Flexor digitorum longus (FDL) – used for smaller defects 
  • Extensor digitorum longus (EDL) – Supplied by anterior tibial artery, for Small wounds Extensor digitorum hallucis – Very narrow. to preserve great toe function, distal tendon should be attached to EDL when dividing the muscle to transfer 
  • Keystone flap (if anterior can be based on AT perforators) 

Lower third 

  • Local flaps 
  • Medial lower third: FHL, FDL, TA 
  • Lateral lower third: peroneus brevus for small defect 
  • Perforator flap 
  • Sural artery flap 
  • Reverse sural artery flap: landmarks are lesser saphenous vein and sural nerve (should bisect cutaneous paddle) 
  • Blood supply is medial superficial sural artery (from peroneal artery and minimal post-tib perforators if reverse); lesser saphenous vein (venae comitantes if reverse) 
  • Point of pivot 5cm above lateral malleolus 
  • Indications include exposed achilles 
  • Partial flap loss occurs commonly, maintain narrow pedicle, and maintain mesentery between sural nerve and deep fascia 
  • Delayed reverse sural flap based on dividing proximal lesser saphenous vein; other delay is raising and setting back or raising distal portion leaving proximal 
  • venous insufficiency adds the most complication risk in this flap 
  • Propeller flap (unequal length island fasciocutaneous flap based on a single perforator off center but inside the skin island) 
  • Posterior tibial artery perforator propeller flap – vessels come between soleus and flexor digitorum longus 
  • perforator flaps for peroneal artery for lateral defects, posterior tib perforators for medial defects 
  • cross leg flap 
  • Calcaneal defects: medial plantar flap: from medial plantar nerve and artery (first metacarpal and midpoint of heal 12x6cm) 
  • pedicle: medial plantar artery (off posterior tibial between flexor hallicus, abductor hallucis and FDB) 
  • nerve: medial plantar nerve (tibial nerve) 
  • Dorsalis pedis flap: SPN, used in dorsal distal foot and anterior ankle 
  • Free flap 

LE Flaps 

  • Free fib supplied by peroneal artery, can be performed safely in smokers 
  • Risks include damage to peroneal/posterior tib nerve; destabilization of ankle <6cm left behind 
  • In patients with CAD/or DM; cook doppler sufficient for pre-operative exam in leg prior to harvesting for fre-fib. No CTA needed 
  • FHL can be injured in deep posterior compartment (results in toe clawing) 

Dorsal foot (DMCA) 

  • Pedicle: dorsal metacarpal artery 
  • Toe-to thumb flap: first dorsal metatarsal from DP artery 2/3 and deep plantar 1/3 
  • Traumatic amputation with preserved parts: covered with filet of “foot” flaps- will be supplied by dorsalis pedis/posterior tib; tibial nerve will supply sensation 


 Bony Recon 

  • <6cm – nonvascularized cancellous bone graft or limb shortening 
  • >6cm – distraction (ilizarov technique), free osseocutaneous flap, masquelet 
  • >10cm – free flap + allograft (Capanna technique), or distraction osteogenesis 1mm/day starting 7d after injury which usually takes a year 
  • Cappana technique: FVFG with bone allograft for segmental reconstruction of LE. Used frequently after sarcoma resection 
  • Bone shortening >10cm results in abnormal gait 
  • Nonvascularized autograft vs vascularized fibula graft: vascularized has increased osteocyte viability, improved strength, healing, and stress response 

Vascular recon 

  • >5.5cm defect –> interposition vein grafting 
  • if super clean, can consider prosthetic grafting (but not in contaminated wounds) 
  • In cold leg –> temporary shunt should be placed followed by bony stabilization –> then vascular repair 
  • Distal venous arterialization bypass: an alternative for limb salvage for severe ischemia and ABI, distal bypass performed to venous vessels of the foot using vein/graft or both 


Nerve recon: principles include tension free repair 

  • primary repair if possible 
  • <3cm – conduit 
  • 3-11cm – cable graft (autologous preferred) with epineurial repair 
  • >12cm – no recovery expected 
  • If nerve undergoes significant crush and is ecchymotic, wait three weeks and then three months and perform EMG, nerve repair with graft if fibrillations are present 
  • If nerve was transected, viable ends would not be stable until 7-10 days 
  • Peroneal nerve palsy: can lead to footdrop/paresthesia after ORIF of tibia, supracondylar femoral fracture, knee dislocation 
  • Wait 2-3 months with emg testing, then perform nerve decompression, neurolysis if in continuity, or repair if transected 
  • Salvage operations include tendon transfer or arthrodesis (posterior tib tendon) 
  • Tibialis posterior – to anterior tendon grafting common procedure to restore dorsiflexion of foot 

Joints – can plaster cast open joint and start abx 

  • van Ness rotationplasty – functional limb below the knee is used to reconstruct more proximal joint defects (ie ankle turned into knee) 
  • Indications for Amputation (if >2 of these are met) (insensate foot no longer indication for amputation) 
  • 3+ fascial compartments 
  • 2+ tibial vessels 
  • Failed vascular recon 
  • Cold foot 
  • Severe crush injury or muscle loss 
  • Age/functional status 
  • BKA – leave 14cm length 


  • Pyoderma gangrenosum – looks like large nonhealing ulcer, cultures negative, no malignancy, and debridement results in larger wound with no healing. often found with other autoimmune diseases. Treat with systemic steroids. 
  • Suspected nerve injury after flap dissection –> exploration and repair 
  • Congenital talipes equinovarus (clubfoot): surgical correction by ilizarov or with acute correction and release of contracted posterior and medial elements; use tissue expansion for soft tissue defects 
  • Latissimus donor site for LE reconstruction: loss of motion and shoulder weakness are the greatest in early post operative period and generally return to baseline at 1 year 
  • Shoulder adduction, extension, and internal rotation 


Sources: ACAPS Inservice exams 2013-2020


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