**Region:** Lower Extremity # Medial Plantar Artery Flap ## Anatomy - Pedicle: named artery (typical diameter/length if present), venae comitantes; course from origin to flap/skin paddle; perforator pattern (number, location, intramuscular vs septocutaneous), choke vessels/adjacent angiosomes. - Artery: medial plantar artery — branch of the posterior tibial artery. The medial plantar artery gives a deep branch (medial branch supplies the medialis pedis flap) and a superficial branch (supplies the instep flap) (Blondeel et al.; Hanasono et al.; Vol. III). - Venae comitantes: small venae comitantes accompany the artery; larger subcutaneous cutaneous veins may be present and can be preserved for venous drainage or used when the flap is transferred as a free flap (Blondeel et al.; Hanasono et al.). - Course: the medial plantar artery runs between the abductor hallucis and flexor digitorum brevis muscles after arising from the posterior tibial system; superficial branch courses between abductor hallucis and flexor digitorum brevis to the instep; deep branch dives toward the medial surface over the tibialis posterior insertion and gives cutaneous perforators to the medialis pedis flap (Blondeel et al.; Hanasono et al.; Vol. III). - Perforator pattern: perforators emerge in the intermuscular plane between abductor hallucis (medial) and flexor digitorum brevis (lateral). Single dominant perforator or multiple perforators are described; medialis pedis flaps have a cutaneous perforator from the deep branch (sometimes a second cutaneous perforator or direct branch from the medial plantar artery exists) (Blondeel et al.; Hanasono et al.; Vol. III). - Intramuscular vs septocutaneous: perforators are located in the intermuscular septum between abductor hallucis and FDB; MPAP (medial plantar artery perforator) may be identified in the septum (Blondeel et al.; Hanasono et al.). - Choke vessels / angiosomes: flap perfusion communicates with plantar arterial networks (superficial and deep plantar arches); when extending pedicle length by ligating branches (eg, lateral plantar artery), collateral circulation and potential need to restore flow should be considered (Blondeel et al.). - Nerves: sensory and motor branches relevant to flap harvest and sensate reconstruction. - Medial plantar nerve runs with the vessels and provides sensory supply to the flap; saphenous nerve territory contributes to medialis pedis sensation in some descriptions (Blondeel et al.; Hanasono et al.; Vol. III). - Sensate harvest techniques: nerve-splitting/internal neurolysis (split fibers entering the flap from the medial plantar nerve) is described to preserve distal sensation while including sensory fibers to make the flap sensate (Vol. III). Instep flap commonly includes the medial plantar nerve branch and requires neurorrhaphy when sensate transfer is desired (Blondeel et al.; Hanasono et al.). - Included tissues: skin/subcutaneous/fascia/muscle; thickness profile; arc of rotation; common variants/anomalies. - Tissues: glabrous plantar skin with subcutaneous tissue and plantar fascia; plantar aponeurosis inclusion optional (Vol. III; Hanasono et al.). - Thickness: instep/medial plantar skin provides durable, often thicker plantar tissue for weight-bearing reconstruction; medialis pedis flap is thinner and suitable for palmar/finger pulp use. Reported medialis pedis/free instep flap sizes used clinically: medialis pedis flaps ranged from 2 × 4 cm to 6 × 8 cm in one series (Blondeel et al.). - Arc of rotation/pedicle length: pedicle length is limited as a local flap; pedicle can be lengthened by dissecting proximally toward posterior tibial vessels and, if necessary, dividing the lateral plantar artery or abductor hallucis. When lateral plantar is sacrificed, arterial continuity may be restored with grafting in selected situations (Blondeel et al.; Vol. III). - Common variants/anomalies: deep branch variations — cutaneous perforator may arise directly from medial plantar artery in some dissections; presence/number of cutaneous perforators variable (Blondeel et al.). ## Dissection Steps 1. Positioning, markings, landmarks. - Position: supine with leg externally rotated and knee flexed (“frog‑leg”) is common; prone or lithotomy options depending on surgeon preference and recipient site (Vol. III; Hanasono et al.). - Landmarks: axis from base/head of first metatarsal distally to sustentaculum tali / medial calcaneal eminence proximally; mark medial malleolus, navicular tubercle, abductor hallucis, and medial plantar artery course as identified by Doppler (Vol. III; Blondeel et al.; Hanasono et al.). - Mark weight‑bearing areas to exclude from flap: plantar forefoot over metatarsophalangeal heads, lateral plantar surface, heel (Vol. III; Hanasono et al.). - Doppler: map main perforator with hand‑held pencil Doppler; center flap over perforator (Vol. III; Hanasono et al.; Blondeel et al.). 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - Recommended plane: subfascial/subplantar aponeurosis dissection to identify perforators in the intermuscular plane between abductor hallucis and flexor digitorum brevis; some authors elevate suprafascially depending on goals, but subfascial is common to protect perforators (Vol. III; Hanasono et al.; Blondeel et al.). - Perforator identification: use hand‑held Doppler preincision; incise lateral/plantar margin first (Hanasono et al.), or incise skin and proceed to fascia — retract abductor hallucis medially to visualize perforators and trace them to their origin (Vol. III; Hanasono et al.; Blondeel et al.). - Tourniquet strategy: literature includes both approaches — a bloodless field (tourniquet inflated) can facilitate anatomy identification (one protocol states inflation to 100 mm Hg above systolic), while others avoid exsanguination/tourniquet to keep vessels filled so perforators and flow can be assessed intraoperatively (Vol. III; Blondeel et al.; Hanasono et al.). Choose according to your operative goals and the need to test perfusion. 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Pedicle exposure: trace perforator proximally from intermuscular plane to medial plantar artery; dissect proximally between abductor hallucis and flexor digitorum brevis to gain pedicle length. Leave a cuff of muscle around pedicle rather than skeletonizing (Hanasono et al.; Blondeel et al.; Vol. III). - Nerve handling: avoid routine transection of medial plantar nerve; perform nerve‑splitting internal neurolysis to include sensory fibers to flap while preserving distal innervation when sensate reconstruction is desired (Vol. III; Blondeel et al.). - Pedicle division options: for pedicled transfer, ligate distal artery then perform distal‑to‑proximal dissection and rotate/transposition into recipient defect. To increase reach or for free transfer, pedicle can be dissected to posterior tibial origin and lateral plantar artery/abductor hallucis/flexor retinaculum may be divided (Vol. III; Blondeel et al.). If lateral plantar is sacrificed and foot vascularity permits, consider restoring flow with an interposition graft (vein or arterial graft) between posterior tibial and lateral plantar stump (Blondeel et al.). - Transfer/inset: rotate or transpose flap into defect avoiding tension; maintain superficial attachments between arterial pedicle and overlying skin until perfusion assessment is satisfactory; preserve and/or coapt sensory nerve when indicated (Vol. III; Hanasono et al.; Blondeel et al.). - Perfusion checks: assess capillary refill, color, bleeding at flap edges; if harvested without tourniquet, intraoperative assessment of perforator flow is possible (Blondeel et al.; Hanasono et al.; Vol. III). 4. Donor-site closure techniques. - Primary closure: narrow medial plantar flaps up to 2 cm in width may be closed primarily (Vol. III). Blondeel et al. reported primary closure possible in ≈ one‑third of medialis pedis donor sites; medialis pedis flaps in their experience ranged up to 6 × 8 cm and many required grafting. - Skin grafting: most donor sites require split‑thickness or full‑thickness skin grafting; reapproximate exposed abductor hallucis and flexor digitorum brevis to create a vascular bed, then apply graft and bolster (negative pressure bolster optional) (Vol. III; Hanasono et al.; Blondeel et al.). - Drains: closed suction drain recommended for donor site if large or when harvest causes dead space (Hanasono et al.; MSAP discussion but applicable). ## Indications and Contraindications - Indications: common reconstructive scenarios; size limits; need for thin vs bulky; sensate needs. - Indications: reconstruction of heel, lateral plantar midfoot, medial malleolus and other plantar defects where glabrous, durable and potentially sensate tissue is required; medialis pedis flap (thin, glabrous and sensate) is useful for palmar/finger pulp reconstruction as free flap and for medial/distal foot coverage as pedicled flap (Vol. III; Blondeel et al.; Hanasono et al.). - Size limits: medialis pedis flap typically used for small–medium defects; reported medialis pedis flap clinical sizes ranged from 2 × 4 cm to 6 × 8 cm (Blondeel et al.). Instep flap provides a larger glabrous surface when needed. - Thin vs bulky: medialis pedis (thin) favored for palmar/finger use; instep flap (thicker) preferred for weight‑bearing heel reconstruction. - Sensate needs: nerve‑splitting or inclusion and coaptation of the medial plantar/medial plantar nerve can produce protective sensation; instep flaps commonly include a thicker sensory nerve that may require neurorrhaphy for sensate reconstruction (Vol. III; Blondeel et al.). - Contraindications: vascular disease, prior surgery/radiation (relative/absolute), comorbidity risks. - Absolute/relative contraindications: occlusion or significant disease of posterior tibial artery or medial plantar pedicle; absent dorsalis pedis perfusion may preclude use depending on peroneal inflow; severe peripheral arterial disease, significant microvascular disease, or prior trauma/scarring that compromises the harvest zone (Vol. III; Hanasono et al.; Blondeel et al.). - Medical optimization: diabetes and smoking should be optimized/ceased preoperatively; peripheral vasculopathy should be corrected prior to reconstruction (Vol. III). ## Postoperative Care - Monitoring schedule/method (clinical, Doppler, implantable probe), warming, antithrombotic practice, positioning/splinting, drains, mobilization, diet/analgesia. - Limb elevation: keep the donor leg elevated — a protocol described mandates elevation for 2 weeks after medial plantar flap (Vol. III). Reverse sural protocols describe strict elevation for 5 days then graduated ambulation; medialis pedis authors recommend a dangling protocol before mobilization (Hanasono et al.; Vol. III; Blondeel et al.). - Dressings: donor site graft bolster removal typically at postoperative day 5, then routine graft care (Vol. III). - Ambulation: allow ambulation once flap sutures and donor site graft are healed and stable; for reconstructions involving underlying fractures follow orthopedic weight‑bearing restrictions (Vol. III). Instep flap used from normal foot to contralateral reconstruction requires prolonged non‑weight‑bearing and causes significant patient inconvenience (Blondeel et al.). - Compression/stockings: for reverse sural experience — after 5 days ambulate with compressive stockings while elevating most of the day; normal activities by day 10; discontinue stockings after 6 weeks (Reverse sural chapter — applicable to peripheral protocols). - Monitoring: clinical checks (color, turgor, capillary refill), hand‑held Doppler over perforator where feasible; no specific implantable probe protocol provided in these texts. - Drains: closed suction drains recommended when donor site dead space exists (Hanasono et al.; MSAP templates). - Antithrombotic: no uniform regimen detailed in these sources; standard perioperative thromboprophylaxis per institutional practice. - Return-to-OR thresholds and time windows. - Indications for immediate return: any suspicion of arterial insufficiency or progressing venous congestion should prompt urgent reassessment and possible re‑exploration. Specific time windows are not defined in the source texts; act promptly per usual microsurgical/ flap practice (Vol. III; Blondeel et al.; Hanasono et al.). ## Complications (rates & management) - Venous congestion, arterial thrombosis, partial/total loss, infection, fat necrosis; include percent/frequency if present. - Reported series: - Siddiqi et al. (series of 18 medial plantar artery flaps): no flap loss; one partial skin graft loss that healed by secondary intention; patients able to wear normal footwear; no reported functional donor‑site morbidity (Vol. III outcomes). - Schwarz & Negrini (51 medial plantar artery flaps in 48 patients): overall complication rate 25.5% (13/51). Most common complications: delayed wound healing N = 6 and infection N = 3. One flap loss reported and 9 ulcer recurrences in 7 feet (Vol. III outcomes). - General complications listed across sources: infection, wound dehiscence, delayed wound healing, skin graft loss, flap loss (partial/total), medial plantar nerve injury with altered sensation, gait disturbance, pain, unstable scar, donor site neuroma (Vol. III; Blondeel et al.; Hanasono et al.). - Donor-site issues (seroma, hematoma, contour deformity, hernia/weakness) with typical frequencies when reported. - Donor‑site: many donor sites require skin grafting; primary closure possible for small widths (≤2 cm) or in ≈ one‑third medialis pedis cases in a series (Vol. III; Blondeel et al.). No numeric rates for seroma/hematoma in these sources. - Management algorithms (re-exploration, leeching, thrombolysis): what, when, how. - Venous problems: most complications are venous in nature for comparable flaps (eg, reverse sural). Strategies include: - Flap delay or staged/delayed harvest in high‑risk patients (smokers, diabetics, peripheral arterial disease, elderly) to improve reliability (Reverse sural; Hanasono et al.). - Modify pedicle design to augment venous drainage (preserve large cutaneous vein if present; include superficial venous system; avoid narrow fascial pedicle) (Blondeel et al.; Reverse sural). - Early re‑exploration for suspected pedicle thrombosis or compromised inflow/outflow — standard microvascular salvage principles apply (sources do not provide stepwise algorithmic times but recommend urgent re‑exploration). - Arterial flow loss after pedicle sacrifice: if lateral plantar artery is ligated to extend pedicle and foot perfusion is compromised or restoration desired, restore blood flow by vein or arterial interposition graft between posterior tibial and lateral plantar stump (Blondeel et al.; case example). - Sensory problems: nerve‑splitting technique to preserve distal sensation or perform nerve coaptation/neurorrhaphy for instep flaps when sensate reconstruction is required (Vol. III; Blondeel et al.). - No explicit guidance on medicinal thrombolysis, leeching or hyperbaric therapy is provided in these PDFs; apply institutional microsurgical salvage protocols when indicated. ## Key Clinical Pearls - Mark and center the flap over the Doppler‑identified perforator; common anatomic axis: base/head of first metatarsal → sustentaculum tali/medial calcaneal eminence (Vol. III; Blondeel et al.). - Avoid harvesting weight‑bearing plantar skin: do not extend flap distal margin onto the metatarsal head; keep distal margin at least 1 cm proximal to the metatarsal head (Blondeel et al.; Vol. III). - Donor closure: narrow medial plantar flaps ≤ 2 cm width can often be closed primarily; most donor sites require split‑ or full‑thickness grafting (Vol. III; Hanasono et al.). - Perforator dissection: expect perforators between abductor hallucis and flexor digitorum brevis; retract abductor hallucis medially and trace perforators proximally—leave a small cuff of muscle around pedicle rather than skeletonizing (Vol. III; Hanasono et al.; Blondeel et al.). - Nerve/sensation: preserve medial plantar nerve via nerve‑splitting internal neurolysis to produce a sensate flap while maintaining distal foot sensation; for instep flaps include and neurorrhaphy of the medial plantar nerve when sensate free transfer is desired (Vol. III; Blondeel et al.). - Pedicle length options: to gain arc/pedicle length consider dividing lateral plantar artery, abductor hallucis muscle, and flexor retinaculum and dissecting pedicle to posterior tibial artery — if lateral plantar is sacrificed, plan for restoration of plantar arterial flow when necessary (vein/arterial graft) (Vol. III; Blondeel et al.). - Tourniquet strategy: two accepted approaches — (a) bloodless field with tourniquet (one described setting: inflate to 100 mm Hg above systolic) to facilitate identification, or (b) avoid exsanguination/tourniquet to keep vessels filled and permit intraoperative perfusion assessment. Choose according to the need to identify anatomy versus assess flow (Vol. III; Blondeel et al.; Hanasono et al.). - Outcomes data points to remember: in one series of 18 medial plantar flaps there was no flap loss; in a larger series of 51 flaps overall complication rate was 25.5% (13/51) with delayed wound healing and infection commonest and one flap loss reported (Vol. III).