**Region:** Lower Extremity # Fibula Flap ## Anatomy - Pedicle: peroneal (fibular) artery and accompanying venae comitantes. The peroneal nutrient endosteal artery is dominant for the diaphysis; musculoperiosteal branches from the peroneal artery supply periosteum and soft tissue. (Volume III: Tibial Reconstruction) - Typical adult fibula dimensions: width 1.5–2 cm; total fibula length ≈35 cm with ~25 cm of diaphysis harvestable for free grafting. (Tibial Reconstruction) - Dominant nutrient artery: branches from the peroneal artery 6–14 cm from the peroneal bifurcation and enters the nutrient foramen in the middle third of the fibular diaphysis; it divides into ascending and descending endosteal branches. (Tibial Reconstruction) - Pedicle length at division: in common practice the vascular pedicle is dissected proximally to the tibioperoneal trunk and may be ligated leaving approximately 2–6 cm of pedicle length on the flap depending on required reach. (Tibial Reconstruction) - Course: peroneal vessels run in the deep posterior compartment between the flexor hallucis longus (FHL) and tibialis posterior (TP) muscles, coursing longitudinally along the posterolateral septum and entering the fibula area posterior to the interosseous membrane. Musculoperiosteal branches run through the posterolateral septum and FHL/TP to the periosteum. (Tibial Reconstruction; Oromandibular reconstruction) - Perforator pattern: - Septocutaneous and musculocutaneous perforators arise from the peroneal artery and concentrate in the middle third of the fibula; the musculoperiosteal branches give segmental rise of approximately 4–8 branches. (Tibial Reconstruction) - Fasciocutaneous perforators supplying a skin paddle travel through the posterior crural septum; skin paddles up to 10 × 20 cm have been described. Majority of fasciocutaneous perforators concentrate at proximal and distal ends of the fibula. (Tibial Reconstruction) - Proximal perforator anatomy is variable: proximal (cranial) musculoseptal perforators may originate higher and run through soleus/FHL and sometimes arise near the bifurcation of peroneal/posterior tibial system—these may require extended dissection or separate anastomosis when included in a proximal skin paddle. (Oromandibular reconstruction) - Choke vessels / angiosomes: longitudinal septocutaneous arrangement with numerous interconnections along the posterolateral septum; periosteal and musculoperiosteal branches create a longitudinal arcade—important for double-paddle and long skin paddles. (Keystone / Tibial Reconstruction) - Nerves: - Common peroneal nerve courses around the fibular head; identify and preserve during proximal dissection to avoid foot dorsiflexion weakness. (Tibial Reconstruction) - Superficial and deep peroneal branches and the deep peroneal (deep fibular) nerve are encountered when reflecting anterior compartment muscles; the sural/saphenous sensory territory is relevant when including skin paddles or planning sensate reconstructions (Oromandibular chapter discusses preservation when designing skin paddles). (Tibial Reconstruction; Oromandibular reconstruction) - Included tissues: cortical bone (diaphysis), medullary canal (small), periosteum, optional skin paddle (osteocutaneous), optional musculocutaneous component (soleus, FHL) for osteomuscular flaps. Flexor hallucis longus may be left with flap (eases dissection) or included for bulk. (Tibial Reconstruction; Oromandibular reconstruction) - Thickness / profile / arc of rotation: - Skin paddle thickness and location depend on perforators through the posterior crural septum; skin paddle may be designed longitudinally on posterolateral calf and can reach distal or proximal defects depending on pedicle length and arc (free and pedicled configurations described). (Tibial Reconstruction) - For pedicled transfer the flap can be transposed through the interval between tibialis posterior and tibialis anterior; reversal/orientation of bone may create a U-turn of the pedicle which must be prevented from kinking. (Tibial Reconstruction) - Common variants/anomalies: - Peronea arteria magna (peroneal-dominant foot circulation) present in ~1%–8% of population — if present, sacrificing peroneal vessels for a flap may compromise foot perfusion; pre-op vascular imaging (Doppler/CTA/MRA) indicated when vascular exam abnormal or trauma history. (Tibial Reconstruction) - Variable proximal musculoseptal perforator origin may necessitate extended dissection into soleus/ popliteal region or a separate vascular anastomosis for proximal skin paddle. (Oromandibular reconstruction) ## Dissection Steps 1. Positioning, markings, landmarks. - Position: supine for contralateral free fibula harvest (allows two-team approach); ipsilateral harvest can be done supine or lateral; prone is used for some pedicled harvests. For supine harvest place a roll under ipsilateral hip and flex knee to 90° (heel stop to hold knee at 90° suitable). Pad pressure points. (Tibial Reconstruction) - Landmarks to mark: head of fibula, lateral malleolus, anterior and posterior fibular borders, planned skin paddle axis along posterior border corresponding to posterior intramuscular septum; mark perforator(s) with handheld Doppler along posterior border if skin paddle planned. (Tibial Reconstruction) - Preserve at least 4 cm of proximal fibula and 6 cm distal to lateral malleolus for knee and ankle stability; maximum harvest length = donor tibia length minus 10 cm. (Tibial Reconstruction) 2. Plane and perforator identification. - Incision: midlateral vertical incision over the fibula; elevate skin flaps to level of investing fascia. Dissect through lateral compartment fascia anterior to posterior intermuscular septum. Preserve posterior intermuscular septum perforators if an osteocutaneous island planned. (Tibial Reconstruction) - Perforator identification: use handheld/IO Doppler pre-op and intra-op to confirm skin paddle perforators along posterior septum. For double-skin-paddle fibula flaps, seek proximal musculoseptal perforators (may require intramuscular dissection through soleus/FHL). (Tibial Reconstruction; Oromandibular reconstruction) - Plane for bone dissection: subperiosteal around the fibula; when including muscle (osteomuscular) include soleus or FHL cuff as planned. (Tibial Reconstruction) 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Identify and protect the common peroneal nerve proximally around fibular head. (Tibial Reconstruction) - Reflect peroneal muscles off anterior fibular surface to expose anterior intermuscular septum; incise septum to access anterior compartment and protect anterior tibial vessels and deep peroneal nerve. (Tibial Reconstruction) - Incise interosseous membrane to enter deep posterior compartment; locate peroneal vessels between tibialis posterior and FHL. Identify peroneal artery and venae comitantes proximally and distally; propagate circumferential dissection medial to vessels using large right-angle clamp, keeping vascular pedicle intact. (Tibial Reconstruction) - Osteotomy: after marking desired fibula length (respect donor bone preservation limits), apply lateral traction with towel clamps and perform osteotomy with oscillating saw or Gigli saw. Include a strip of periosteum across osteotomy to facilitate overlap at recipient site. Prior to osteotomy, microvascular clamp peroneal artery distal to osteotomy to confirm foot perfusion and then divide. (Tibial Reconstruction) - Pedicle length: dissect pedicle distally and then proximally up toward tibioperoneal trunk; ligate and divide appropriately, leaving ~2–6 cm pedicle as needed. (Tibial Reconstruction) - After release of tourniquet, confirm robust arterial inflow and venous outflow and back-bleeding from periosteum and intramedullary canal. (Tibial Reconstruction) - Transfer and inset: bone is telescoped into intercalary defect and fixed with long compression plates and screws spanning defect; protect pedicle from compression—fat grafts can be placed around pedicle to cushion and prevent compression. Perform microvascular anastomosis between recipient vessels (as planned) and peroneal artery/venae comitantes. (Tibial Reconstruction) - For pedicled fibula: do not divide proximal pedicle, transpose bone through plane between tibialis posterior and tibialis anterior; ensure pedicle length and orientation avoid kinking (especially if flap reversed 180°). (Tibial Reconstruction) - For double-barrel fibula: osteotomize harvested fibula at midpoint and fold (double-barrel) keeping peroneal vessels intact; subperiosteal elevation over 2–3 cm at osteotomy site allows protection of pedicle during folding. Double-barrel technique appropriate for shorter intercalary defects (≤13 cm). (Tibial Reconstruction) 4. Donor-site closure techniques. - Decide closure based on flap width and soft-tissue mobilization: longitudinal skin paddles commonly allow primary closure; donor defects >3 cm width often require split-thickness skin graft. Place drains in donor site as needed. (Tibial Reconstruction; Reverse Sural) - Posterior leg splint with foot in extension applied after closure to prevent equinus deformity. (Tibial Reconstruction) ## Indications and Contraindications - Indications: - Segmental long-bone reconstruction (tibial intercalary defects) after trauma, tumor resection, osteomyelitis, or radiation-induced necrosis — fibula provides vascularized autograft that hypertrophies under load. (Tibial Reconstruction) - Composite defects requiring bone with soft tissue (osteocutaneous or osteomuscular), or when double-paddle skin islands required (e.g., through-and-through oromandibular defects). (Tibial Reconstruction; Oromandibular reconstruction) - Tibial defects requiring durable long-term reconstruction where hypertrophy and biological incorporation are desired. (Tibial Reconstruction) - Double-barrel fibula for proximal tibial reconstruction when defect ≤13 cm. (Tibial Reconstruction) - Practical size limits / tissue selection: - Single fibula harvest typically provides up to ~25 cm diaphysis; maintain 4 cm proximally and 6 cm distally. Maximum graft length = donor tibia length minus 10 cm. (Tibial Reconstruction) - Skin paddle up to 10 × 20 cm reported (typical perforator distribution makes skin paddle design posterior-lateral). (Tibial Reconstruction) - Double-barrel technique increases cross-sectional area but is best for defects <13 cm. (Tibial Reconstruction) - Contraindications: - Peronea arteria magna (peroneal-dominant foot) without alternative revascularization — presence in ~1%–8% population; may preclude sacrifice of peroneal vessels (pre-op vascular imaging if concern). (Tibial Reconstruction) - Severe peripheral vascular disease occluding peroneal arterial supply to foot or donor leg; prior ipsilateral trauma fracturing fibula or injuring vascular supply (consider contralateral donor). (Tibial Reconstruction) - Poor general health/frailty making complex long reconstruction and rehabilitation inadvisable. (Tibial Reconstruction) ## Postoperative Care - Monitoring schedule and methods: - Clinical exam and handheld Doppler monitoring every hour for first 24 hours (monitor both recipient skin paddle if present and anastomosis signals). Continue regular assessments until discharge. (Tibial Reconstruction) - Positioning / splinting: - Posterior leg splint with foot in extension to prevent equinus following closure. Non–weight-bearing initially. (Tibial Reconstruction) - Mobilization: - No weight-bearing on the surgical limb for up to 2 weeks initially; then progressive partial weight-bearing with assistance; full weight-bearing after radiographic and clinical evidence of bone union. (Tibial Reconstruction) - Antithrombotic practice / warming / drains / diet / analgesia: - Use of drains at donor site and recipient site as indicated; close attention to hemostasis and avoid compression of pedicle with dressings. Specific institutional antithrombotic regimens not specified in source texts—monitor clinical perfusion with Doppler. (Tibial Reconstruction) - Return-to-OR thresholds and time windows: - Primary cause of flap loss is vascular thrombosis—early postoperative vascular compromise should prompt urgent reexploration (text lists vascular thrombosis as main cause of flap loss but does not mandate an exact time window). Use clinical and Doppler findings for decision. (Tibial Reconstruction) ## Complications (rates & management) - Recipient-site complications: - Vascular thrombosis → flap loss (listed as primary cause of loss). Prompt recognition and re-exploration indicated (specific time windows not specified in source text). (Tibial Reconstruction) - Nonunion; infection; hardware failure/malfunction. (Tibial Reconstruction) - Donor-site complications: - Inability to flex great toe from flexor hallucis longus injury (when included or injured). (Tibial Reconstruction; Oromandibular reconstruction) - Knee or ankle instability, valgus deformity or secondary pseudoarthrosis if insufficient bone left proximally or distally — preserve ≥4 cm proximal and ≥6 cm distal to maintain stability. (Tibial Reconstruction) - Common peroneal nerve injury during proximal dissection. (Tibial Reconstruction) - Reported frequencies / outcomes (numbers reported in source): - Union time: 3–7 months. (Tibial Reconstruction) - Union rates: upward of 75%. (Tibial Reconstruction) - Ambulation: reported 100% of patients ambulatory at follow-up, average 9.5 to 14.3 months. (Tibial Reconstruction) - Joint stiffness: ~40%; chronic pain: ~18%. (Tibial Reconstruction) - Management algorithms (what, when, how — limited to described measures): - Prevention: preserve pedicle tissue cuff, avoid pedicle compression (use fat grafts around pedicle), confirm distal foot perfusion before dividing peroneal vessels, perform intraoperative clamp test before division. (Tibial Reconstruction) - If venous/arterial insufficiency suspected: clinical/Doppler monitoring and consideration for urgent return to theatre for exploration of anastomosis—vascular thrombosis cited as primary cause of flap loss. (Tibial Reconstruction) - For pedicled transfers: if distal perfusion marginal, consider measures described for pedicled flaps (ensure no pedicle kinking if flap reversed; avoid excessive torsion). (Tibial Reconstruction) - For donor-site ankle instability when distal osteotomy close to lateral malleolus: screw fixation to tibia may be utilized to prevent valgus deformity/instability (particularly in pedicled flaps). (Tibial Reconstruction) ## Key Clinical Pearls - Always preserve at least 4 cm of proximal fibula and 6 cm distal above lateral malleolus to maintain knee and ankle stability. (Tibial Reconstruction) - Preoperatively assess donor leg arterial anatomy when vascular disease or prior trauma suspected; peronea arteria magna occurs in ~1%–8%—if present, avoid sacrificing peroneal artery unless reconstruction of foot inflow is planned. (Tibial Reconstruction) - Mark the fibula harvest landmarks: head of fibula, lateral malleolus, anterior/posterior fibular borders; mark perforator for skin paddle along posterior intramuscular septum with Doppler. (Tibial Reconstruction) - Prior to osteotomy clamp the peroneal artery distal to planned bone division to ensure adequate foot perfusion; only divide if distal circulation acceptable. (Tibial Reconstruction) - Include a strip of periosteum across osteotomy ends to promote overlap and union at recipient site. (Tibial Reconstruction) - When planning double-skin-paddle fibula flaps, identify proximal musculoseptal perforators early—they can originate cranially and may require dissection through soleus/FHL or a separate anastomosis; distal (septal) paddle tends to be fixed and best for intraoral lining, proximal paddle (long descending perforators) best for external skin. (Oromandibular reconstruction) - For double-barrel constructs: use for defects up to ~13 cm; elevate pedicle subperiosteally over 2–3 cm at osteotomy midpoint to protect pedicle when folding. (Tibial Reconstruction) - After inset and microvascular anastomosis, protect pedicle from compression with soft fat grafts and choose fixation strategy that avoids stress to the vascular pedicle; keep posterior leg splinted with foot in extension to prevent equinus. (Tibial Reconstruction)