Supine Position | Dorsal Cutaneous Nerves at Risk | Subperiosteal Exposure
Surgical Imaging
The dorsal cutaneous nerves (branches of superficial peroneal nerve) cross the operative field in the subcutaneous layer. They must be identified, mobilised and protected with vessel loops or gentle retraction. Injury leads to sensory loss on the dorsum of the foot and risk of painful neuroma formation. Always look for them before incising fascia.
The extensor digitorum longus and brevis tendons overlie the metatarsals. They are retracted medially or laterally rather than divided. Division leads to extensor lag or claw toe deformity of the affected ray. Identify the tendon, place a loop around it and retract gently throughout the case.
All dissection on the metatarsal is performed subperiosteally to protect the tenuous blood supply to the metatarsal head. This is especially critical in Freiberg disease where the head is already avascular. Periosteal elevation must be gentle and circumferential only as far as needed for the procedure.
A single longitudinal incision placed in the intermetatarsal space can access two adjacent metatarsals when the skin bridge is adequate (greater than 3 mm). Two parallel incisions require a minimum 5 mm skin bridge to avoid necrosis. Plan incisions based on which rays require surgery.
Use a thigh or calf tourniquet with the patient supine and the foot at the end of the table. This allows easy fluoroscopic access in AP, oblique and lateral projections. Exsanguinate the limb and inflate to 250-300 mmHg. Limit tourniquet time to less than 90 minutes when possible.
When performing Weil osteotomy or head resection, precise restoration of metatarsal length and cascade is essential. Shortening one ray by greater than 2-3 mm relative to adjacent rays risks transfer metatarsalgia to the neighbouring metatarsal head. Always check the metatarsal parabola intra-operatively with fluoroscopy.
At a Glance
The dorsal approach to the lesser metatarsals (rays two through five) is the workhorse exposure for forefoot reconstructive surgery and central ray trauma. It is performed with the patient supine under tourniquet control. One or two longitudinal incisions are placed on the dorsum of the forefoot. The key at-risk structures in the superficial layer are the dorsal cutaneous nerves (purely sensory branches of the superficial peroneal nerve). The extensor tendons are identified and retracted rather than divided. Deep dissection is subperiosteal along the metatarsal shaft, neck and head. This approach allows excellent visualisation for Weil osteotomy, metatarsal fracture fixation, metatarsal head resection in Freiberg disease, and access for ray amputation. Because the nerves at risk are sensory only, permanent motor deficit is rare, but neuroma pain can be debilitating if technique is poor.
DORSALMTDORSAL MT - Surgical Steps
Hook:DORSAL MT approach - always protect the nerves and retract the tendons!
NERVESAFENERVE SAFE - Danger Structures
Hook:Keep NERVE SAFE and you will avoid the common complications of this approach!
PROCEDURESPROCEDURES - Common Uses
Hook:The dorsal approach opens the door to all these PROCEDURES on the lesser rays!
Indications and Approach Selection
Primary Indications:
- Weil osteotomy for lesser metatarsalgia and metatarsal length abnormalities
- Open reduction and internal fixation of central ray metatarsal fractures (neck, shaft or head)
- Surgical management of Freiberg disease (infraction of lesser metatarsal head)
- Metatarsal head resection for intractable plantar keratosis or Freiberg collapse
- Partial or complete ray amputation for infection, tumour or severe deformity
- Revision surgery for malunion, non-union or failed previous osteotomy
Why This Approach is Chosen:
The dorsal approach provides direct, extensile access to the entire length of the lesser metatarsals from the tarsometatarsal joint to the head. It is superficial, relatively bloodless under tourniquet, and allows one incision to address two adjacent rays when placed correctly. No major motor nerve is at risk and the approach can be extended proximally or distally as needed.
Contraindications:
- Active infection in the skin over the planned incision (consider staging or alternative)
- Severe peripheral vascular disease with non-palpable dorsalis pedis pulse (assess perfusion first)
- Previous surgery with extensive scarring that would require a different plane
- Isolated first ray pathology (use medial approach instead)
Alternative Approaches:
- Plantar approach: rarely used for lesser metatarsals due to weight-bearing skin and difficult access
- Medial approach to first metatarsal: for hallux pathology or first ray procedures
- Lateral approach to fifth metatarsal: for fifth metatarsal base fractures or bunionette
Overview
Dorsal Approach to the Lesser Metatarsals provides direct access to the shafts, necks and heads of the second, third, fourth and fifth metatarsals through one or more longitudinal dorsal incisions.
Key Characteristics:
- Patient positioned supine with tourniquet
- Dorsal cutaneous nerves are the primary structures at risk
- Extensor tendons are retracted rather than divided
- All deep dissection is performed subperiosteally
- One incision can address two adjacent rays
Why This Approach Matters:
- Lesser metatarsal pathology (metatarsalgia, fractures, Freiberg) is extremely common in foot and ankle practice
- The approach is versatile and can be used for both elective reconstruction and trauma
- Proper nerve handling prevents chronic neuropathic pain
- Precise length restoration avoids transfer metatarsalgia, a frequent cause of revision
Exam Relevance:
- High-yield surgical approach for Operative Surgery and Viva stations
- Internervous plane and danger structures are classic examiner questions
- Understanding the metatarsal cascade and parabola is essential for Weil osteotomy planning
Anatomy
Bony Anatomy:
The lesser metatarsals (two through five) articulate proximally with the tarsometatarsal joints and distally with the proximal phalanges. The metatarsal heads form the metatarsal parabola, which is critical for even weight distribution across the forefoot. The second metatarsal is typically the longest and bears the most load. The metatarsal neck is the common site for stress fractures and Weil osteotomy. The head has a tenuous retrograde blood supply from the metatarsal shaft and is vulnerable to avascular necrosis in Freiberg disease.
Muscular and Tendinous Layers:
The extensor digitorum longus tendon runs superficially over each metatarsal and inserts into the dorsal apparatus of the toe. The extensor digitorum brevis originates from the dorsum of the calcaneus and inserts into the lateral aspect of the long extensor tendons of the lesser toes. These tendons are retracted during the approach rather than divided.
Neurovascular Anatomy:
The dorsal cutaneous nerves (medial dorsal cutaneous nerve, intermediate dorsal cutaneous nerve and lateral dorsal cutaneous nerve) are branches of the superficial peroneal nerve. They cross the dorsum of the forefoot in the subcutaneous plane and supply sensation to the skin. The dorsalis pedis artery continues as the deep plantar artery after giving off the dorsal metatarsal arteries, which run deep to the extensor tendons in the intermetatarsal spaces. These vessels are protected by staying on bone during deep dissection.
Metatarsal Head Vascularity:
The metatarsal head receives blood supply from both the metatarsal shaft (nutrient artery) and from the capsule and collateral ligaments. Circumferential periosteal stripping can devascularise the head and must be avoided, especially in Freiberg disease where the head is already compromised.
Internervous Plane
Deep Internervous Plane:
There is no true classical internervous plane in the dorsal approach to the lesser metatarsals. The approach is performed in the extra-compartmental dorsal subcutaneous and subperiosteal planes. The superficial peroneal nerve branches (dorsal cutaneous nerves) are sensory only and are protected rather than used as an internervous landmark. The extensor tendons (innervated by the deep peroneal nerve for EDB and superficial peroneal for EDL contribution) are simply retracted.
Superficial Dissection:
The skin and subcutaneous tissue are incised. The dorsal cutaneous nerves are identified in the subcutaneous fat and carefully mobilised with vessel loops or gentle retraction. No muscle is divided. The fascia over the extensor tendons is incised and the tendons are retracted to expose the periosteum of the metatarsal.
Structures at Risk in Each Layer:
- Structure
- Dorsal cutaneous nerves (medial, intermediate, lateral)
- Protection Strategy
- Identify early, mobilise gently, use vessel loop, avoid cautery near nerves
- Structure
- Extensor digitorum longus and brevis tendons
- Protection Strategy
- Identify, loop and retract medially or laterally - never divide
- Structure
- Dorsalis pedis and dorsal metatarsal arteries
- Protection Strategy
- Stay strictly subperiosteal on the metatarsal - arteries lie in intermetatarsal spaces
- Structure
- Metatarsal head blood supply
- Protection Strategy
- Limit circumferential elevation, preserve capsular attachments where possible
- Structure
- Metatarsophalangeal joint capsule
- Protection Strategy
- Incise only as needed for head access, protect collateral ligaments
The dorsal approach relies on intermuscular and subperiosteal dissection rather than a true internervous plane. The key safety principle is identification and protection of the purely sensory dorsal cutaneous nerves in the subcutaneous layer, followed by tendon retraction and strict subperiosteal dissection on bone. This avoids injury to the deep peroneal nerve (which lies more laterally and supplies EDB) and protects the tenuous retrograde blood supply to the metatarsal head.
Positioning and Patient Setup
Position: Supine on Radiolucent Table
Pre-positioning Checklist:
- Apply thigh or calf tourniquet before exsanguination
- Position the patient with the foot at the very end of the table for easy fluoroscopic access
- Place a small bolster under the ipsilateral hip if needed for internal rotation
- Pad all pressure points including the contralateral heel and sacrum
- Ensure the C-arm can obtain true AP, oblique and lateral views of the forefoot without obstruction
Positioning Details:
- Patient supine with the operative foot prepared and draped free
- Tourniquet inflated to 250-300 mmHg after exsanguination
- Foot is plantarflexed slightly at the ankle to relax the extensor tendons
- A small sandbag or bump under the forefoot can improve access to the plantar aspect if needed
- Fluoroscopy is brought in from the opposite side of the table
Prolonged tourniquet time greater than 90 minutes increases the risk of nerve palsy and muscle damage. Document tourniquet time and consider deflating for 10-15 minutes if the procedure is prolonged. In patients with peripheral vascular disease, consider surgery without tourniquet or with careful monitoring.
Alternative Positioning:
- Lateral decubitus is rarely required but can be used if combined procedures on the lateral foot are planned
- Prone positioning is not used for this approach
Surface Anatomy and Landmarks
Key Bony Landmarks:
- Metatarsal heads - palpable prominences on the ball of the foot
- Metatarsal shafts - can be palpated along the dorsum of the forefoot
- Tarsometatarsal joints - felt as slight depressions proximally
- Base of fifth metatarsal - prominent landmark on the lateral border
Key Soft Tissue Landmarks:
- Extensor digitorum longus tendons - visible and palpable when the toes are extended
- Superficial veins on the dorsum - avoid when possible to reduce bleeding
- Skin creases - note any previous surgical scars
Incision Planning:
- Longitudinal incision placed directly over the metatarsal shaft for single-ray access
- For two-ray access, place the incision in the intermetatarsal space between the two target rays
- Length typically 4-6 cm centred over the surgical target (neck for Weil, shaft for fracture)
- Extend proximally to the tarsometatarsal joint if proximal access is required
- Maintain a minimum 5 mm skin bridge between any parallel incisions
Surgical Technique
Patient Positioning
The patient is positioned supine on a radiolucent table with a thigh or calf tourniquet applied. The foot is placed at the end of the table to allow unobstructed fluoroscopic imaging in multiple planes. The limb is exsanguinated and the tourniquet inflated to 250-300 mmHg. A small bolster under the ipsilateral hip may be used to facilitate internal rotation of the leg if required for access to the central rays.
Surface Landmarks
The metatarsal heads are palpated on the plantar aspect and their dorsal projections marked on the skin. The shafts are traced proximally toward the tarsometatarsal joints. The planned incision is marked directly over the target metatarsal or in the intermetatarsal space for two-ray access. The course of visible dorsal veins is noted and avoided when possible.
Equipment Preparation
A small fragment set with 2.0 mm and 2.4 mm screws, K-wires, a microsagittal saw, and appropriate osteotomy guides or jigs for Weil osteotomy should be available. Intra-operative fluoroscopy is mandatory to confirm length, rotation and fixation.
Viva Scenarios
Practise clinical reasoning and management decisions out loud
“A 45-year-old woman with central metatarsalgia has failed conservative treatment. CT shows a long second metatarsal. Describe how you would perform the dorsal approach and Weil osteotomy.”
“A 28-year-old footballer sustains a displaced fracture of the third metatarsal neck after a tackle. Describe your surgical approach and fixation strategy.”
“A 16-year-old gymnast presents with Freiberg disease of the second metatarsal head with collapse and loose body. How would you approach surgical management?”