Leg
- 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
Thigh
- Compartments: Anterior, posterior, medial
- Layers: epidermis, dermis, two layers of fat, colles fascia
- Colles attaches to ischiopubic rami, scarpas fascia, perineum/medial thigh junction
Vasculature
- 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
Innervation
- 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
Infection
- 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
Amputations
- 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
Gracilis
- 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
ALT
- 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
Gastroc
- 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
- 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
Miscellaneous
- 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
https://www.orthobullets.com/trauma/1003/gustilo-classification