Plantar Medial Approach to the Foot

What it exposes. The plantar-medial approach is the utility exposure of the sole. Made along the medial glabrous skin junction, it reaches the plantar aponeurosis, the flexor hallucis longus tendon, the medial and central plantar spaces, and — through its proximal extension — the tarsal tunnel and posterior tibial neurovascular bundle. It is the workhorse approach for plantar fascia release, plantar fibroma excision in Ledderhose disease, drainage of deep plantar-space infection, and exposure of FHL for harvest or tenolysis. Why medial (and not on the sole). A scar placed on the weight-bearing plantar skin causes a painful plantar keratosis or intractable plantar scar that is far harder to treat than the original problem. The medial border of the foot carries a visible line where the thin hair-bearing skin meets the thick glabrous plantar skin; this junction lies on non-weight-bearing skin, heals reliably, and gives direct access to the deep plantar structures through a single mobilisable flap. This single principle — incise along the glabrous junction, not the sole — is the most examined concept in plantar approaches. Position & landmarks. Supine with a sandbag under the ipsilateral hip and the affected leg fully externally rotated, so the medial border of the foot faces the surgeon directly — this is NOT a prone approach. A high-thigh pneumatic tourniquet gives a bloodless field, though for an infected diabetic foot the tourniquet may be omitted or used at low pressure so the viable skin edge can be judged. Pad all bony prominences (especially the contralateral fibular head and lateral malleolus once the leg rolls externally), confirm the lateral image-intensifier view is achievable, and mark the incision before draping with the foot in the operative position because the glabrous junction shifts with rotation. Surface landmarks to palpate and mark: - Medial malleolus — the posterior reference for the proximal extension toward the tarsal tunnel

• Sustentaculum tali — the bony shelf one fingerbreadth below the medial malleolus, beneath which the tarsal tunnel contents and FHL pass
• Navicular tuberosity — the medial midfoot prominence marking the tibialis posterior insertion
• Medial calcaneal tubercle — the origin of the plantar aponeurosis, the target for fascia release
• First metatarsal head and hallux — the distal reference for forefoot extension
• The glabrous skin junction — the most important landmark of all

Approach variants. A medial glabrous utility incision runs along the hair-to-glabrous junction on the medial border and reaches the plantar fascia, plantar fibroma, FHL and the medial and central plantar spaces. An extended medial hindfoot incision continues behind and below the medial malleolus into the tarsal tunnel for tarsal tunnel release, posterior tibial tendon or tibial nerve decompression. A direct plantar (curvilinear) incision on the sole itself is used only when no medial route will reach the lesion — a large central plantar mass, extensive Ledderhose disease, or diffuse infection.

Work down through the layers along the glabrous junction, retracting abductor hallucis dorsally to open an intermuscular (not internervous) plane, identifying and protecting the medial and lateral plantar nerves as they appear, until the target structure — plantar fascia, FHL, fibroma or plantar space — is reached.

The surgeon descends through four layers to reach the deep structures. Knowing the contents of each layer tells you where the danger lies at every step.

Structures at risk, by layer. The danger shifts as you descend: the medial calcaneal nerve is at risk superficially at the proximal wound, the medial plantar nerve lies on top of the first muscular layer, and both plantar nerves and their vessels run within the second layer where most of the deep work happens.

The posterior tibial bundle proximally. When the incision is extended proximally behind the medial malleolus, the tarsal tunnel contents come into play. From anterior to posterior within the tunnel lie the tibialis posterior tendon, the flexor digitorum longus tendon, the posterior tibial artery and veins, the tibial nerve, and the flexor hallucis longus tendon — the classic mnemonic Tom, Dick and Nervous Harry. The artery and nerve are centrally placed and at greatest risk; here the nerve divides into the medial plantar, lateral plantar and medial calcaneal branches. The plantar nerves — the core anatomy. The tibial nerve reaches the foot behind the medial malleolus and divides into three terminal branches within or just proximal to the tarsal tunnel. The medial calcaneal nerve branches early to supply sensation to the plantar heel (single or multiple, at risk at the proximal end of the incision). The medial plantar nerve — the larger branch, the foot's equivalent of the median nerve — runs deep to abductor hallucis between it and flexor digitorum brevis, supplies abductor hallucis, flexor digitorum brevis, flexor hallucis brevis (medial) and the first lumbrical, and gives sensation to the medial three and a half toes. The lateral plantar nerve — the smaller branch, the foot's equivalent of the ulnar nerve — runs obliquely from medial to lateral deep to flexor digitorum brevis toward the base of the fourth metatarsal, supplies all remaining intrinsics, and gives sensation to the lateral one and a half toes; it is the most easily injured structure because it crosses the field.

Closure — the plantar wound is the operation. Plantar wound healing is unforgiving; a poorly closed or poorly offloaded wound produces a depressed scar, painful callosity, dehiscence or deep infection. Close in three layers: first the plantar aponeurosis with absorbable suture (restoring the load-bearing envelope and preventing a depressed scar); then the dense fibrous subcutaneous septa with absorbable interrupted sutures (obliterating dead space and re-contouring the fat pad); then the thick plantar skin with non-absorbable vertical or horizontal mattress sutures to evert the edges, because inversion under load produces a painful ridge. Achieve meticulous haemostasis of the plantar venous plexus before closure and use a drain for large dead spaces, particularly after infection drainage or wide fibroma excision. Post-operative offloading. Strict offloading in a cast boot or non-weight-bearing regimen for two to three weeks until the wound is sealed and dry; longer for diabetics, smokers and after infection drainage, where wound failure is common. Heel-walking or a forefoot-offloading shoe may be used once the wound is stable. Review the wound at 48 hours then weekly, watching for dehiscence, haematoma and early infection.

• Open plantar fascia release for refractory plantar fasciitis (largely superseded by endoscopic or percutaneous medial release, but the open medial route remains the teaching standard)
• Excision of plantar fibroma in Ledderhose disease, often with a segment of aponeurosis
• Drainage of deep plantar-space infection, especially the medial and central compartments in the diabetic foot
• Exposure of flexor hallucis longus for FHL harvest in Achilles tendon reconstruction or for tenolysis
• Tarsal tunnel release through the proximal extension
• Excision of plantar soft-tissue masses, avoiding a weight-bearing scar

The plantar-medial approach is a classical surgical exposure rather than an implant-based procedure, so there are no arthroplasty or implant registries that track it. The principles are convergent across examination systems (advanced orthopaedic practice and advanced orthopaedic practice, DNB and MS, MRCS, SICOT): incise on non-weight-bearing skin, recognise that there is no true internervous plane, protect the plantar nerves directly, and close in layers with strict offloading.

Global practice variation: the most genuine variation lies in technique choice rather than exposure principles. For plantar fasciitis, endoscopic and percutaneous medial release have largely replaced open release in high-resource settings because they spare the medial calcaneal nerve and allow earlier weight-bearing, while the open medial release remains the reference standard in teaching and in resource-limited settings. For Ledderhose disease and plantar-space infection, practice varies in the extent of fascial excision and in drainage strategy, but the shared principle of avoiding a weight-bearing scar and protecting the plantar nerves is universal. Consent (globally applicable): discuss nerve injury to the medial or lateral plantar nerves with residual numbness or neuroma, painful plantar scar or keratosis if the sole is incised, wound dehiscence (especially in diabetics and smokers), haematoma from the plantar venous plexus, infection, and recurrence for fibroma or incomplete-release fasciitis.