TENS Nail for Ulnar Fractures

What is TENS?

Indications

• Unstable or displaced diaphyseal ulnar fractures in children (typically ages 5-14)
• Both-bone forearm fractures (radius + ulna) - most common scenario
• Monteggia fractures - TENS nail to the ulna + closed reduction of the radial head
• Fractures that fail or are likely to fail closed reduction and casting (older children, proximal fractures)
• Re-fractures / refractures after previous manipulation
• Open forearm fractures (relative indication)

Nail Selection

• The isthmus diameter is measured on plain radiographs; reaming is rarely needed in children
• Both nails should ideally be the same diameter for balanced elastic forces
• Nails come pre-bent or are bent intraoperatively using a nail bender

Surgical Technique - Ulnar TENS Nail

Patient Positioning

• Supine with a radiolucent arm board
• Tourniquet applied at the level of the arm
• Fluoroscopy (image intensifier) mandatory throughout

Entry Point for the Ulna

1. A 1-cm longitudinal incision is made over the tip of the olecranon
2. The triceps insertion is split longitudinally
3. The starting point is created 5-8 mm from the dorsal cortex and 5 mm from the lateral cortex of the proximal ulna
4. This positioning allows insertion of a straight nail despite the natural lateral bow of the ulna, and avoids the articular surface of the greater sigmoid notch
5. A drill guide is strongly recommended to protect surrounding soft tissues
6. ⚠️ The ulnar nerve is at special risk during creation of the proximal ulna entry point

Alternatively, the ulna can also be nailed retrograde (distal to proximal), entering just proximal to the distal ulnar physis. The antegrade approach is preferred for most shaft fractures.

Nail Insertion Steps

1. Prepare the canal: If open reduction is performed, ream the canal through the fracture site both proximally and distally. Reaming of the distal segment is important as cancellous bone can impede nail advancement and cause fracture distraction
2. Bend the nail: Adjust nail geometry to match the lateral bow of the ulna using a nail bender
3. Advance the nail: Insert the nail with a T-handle driver or inserter. Keep a short working length (3-5 cm between entry point and inserter) for better control
4. Reduce the fracture: The nail tip can be used as a lever to assist in closed reduction as it approaches the fracture site
5. Cross the fracture site under fluoroscopic guidance and seat the nail distally
6. Cut the nail tail: Cut the nail close to the bone (or slightly proud). If using a lateral entry, ensure the nail end does not irritate the superficial radial nerve
7. End caps: Optional - can be inserted over nail ends to reduce irritation and migration

⚠️ Do not use a hammer if the nail is stuck (especially in young children with narrow canals) - withdraw 2 cm, rotate to free the tip, then re-advance.

Order of Fixation (Both-Bone Forearm)

• Fix the radius first (retrograde, distal entry near Lister tubercle) - this is usually advantageous
• If the radius is difficult to reduce, use a distal ulnar entry for both nails so they go in the same direction, enabling simultaneous manipulation
• If the radius reduces easily, choose the ulnar entry point furthest from the fracture to give maximum working length
• Fix the less comminuted fracture first to guide reduction of the other bone

Aftercare

• Cast immobilization is not strictly necessary but is often applied for 3-4 weeks for comfort, especially in younger children
• For Monteggia type, immobilize in the position of maximum stability of the radiocapitellar joint for 2-4 weeks
• Encourage use of the arm early
• First follow-up (clinical + radiological): 4-6 weeks post-op
• Mean union time: approximately 10 weeks

Nail Removal

• Delayed until fracture has remodeled completely
• Performed as a day case under general anaesthesia
• The proximal ulna nail end can often be easily palpated
• Distal nail tips may slip under tendons/nerves and can be difficult to locate

Outcomes

Complications

TENS vs. Plate Fixation (Adults)

• Plates restore cortical contact and rotational stability better
• IM nails (including elastic nails) cannot control rotation and axial length in comminuted patterns without locking
• Union rates with plates approach 97-100%

• Rockwood and Green's Fractures in Adults, 10th ed. 2025 - Intramedullary Nailing of Forearm Fractures
• AO Surgery Reference - ESIN for Forearm (Pediatric Trauma)
• Jain S et al. Acta Orthop Belg. 2023 - PMID 37935240
• Bhat et al. Trauma Monthly. 2022
• PMC5198410 - Prospective study of 50 cases

Medial Malleolus Plating

Overview of Fixation Options

When to Use a Plate (Indications)

1. Vertical Shear Fracture (Supination-Adduction / SAD Pattern)

• McConnell and Tornetta found 42% of vertical shear medial malleolar fractures had associated plafond impaction
• Their series used antiglide plates in 6 of 9 cases, with good outcomes at mean 2.4 years

2. Comminuted Fragment

3. Small Fragment (Too Small for Dual Screws)

4. Osteoporotic Bone / Diabetic Patients

Plate Types for the Medial Malleolus

A. Anti-Glide / Buttress Plate

• A one-third tubular plate or dedicated medial anti-glide plate (e.g., Acumed, ~70 mm)
• Placed along the medial surface of the distal tibia, proximal to the fracture apex
• Acts as a buttress against vertical shear - proximal screws grip the metaphysis, distal screws or the plate edge bear against the fragment
• Functions similarly to a one-third tubular plate but purpose-contoured to the distal tibial medial surface
• Distal hole clusters often sized for 2.7 mm screws to capture small/comminuted fragments

B. Hook Plate

• Distal prongs (2-pronged "fork") engage under the tip of the malleolus
• Ideal for avulsion-type small fragments or severely comminuted distal tips that cannot accept screws
• Available in standard and locking peg variants (e.g., locking peg hook plate adds a 2.3 mm locking cortical peg across the fracture)
• Can be placed on medial or lateral malleolus
• Pre-drilling with 2.0 mm K-wires is an option in hard bone before hook engagement

C. Contoured T-Plate / Mini-Fragment Plate

• A small T-plate or 2.0/2.4 mm mini-fragment plate contoured to the medial malleolar anatomy
• Used for complex small fragment patterns
• Case series report good radiologic outcomes; biomechanical data encouraging

Surgical Technique - Medial Malleolus Plating

Preoperative Planning Checklist

• Radiolucent operating table
• Supine position; radiolucent block under injured ankle
• C-arm from contralateral side
• Tourniquet at 250 mmHg
• Implant selection based on fragment size, fracture pattern, and bone quality

Patient Setup

• Supine, foot near end of table
• Tourniquet applied
• Fluoroscopy set up contralaterally for AP and mortise views

Incision and Approach

1. Longitudinal incision placed directly over the medial malleolus (some prefer a hockey-stick incision, convex anteriorly, beginning just anterior to the malleolus)
2. Blunt dissection down to bone to avoid injuring the great saphenous vein and nerve running just anterior to the malleolus
3. Distract the fracture to remove hematoma, bone debris, and any periosteal flap dragged into the fracture from the proximal fragment

Fracture Reduction

1. Apply a small pointed reduction clamp - place a small drill hole just proximal to the fracture for the proximal tine; distal tine at the malleolar tip
2. Progressively compress while manually correcting translation - placing the index finger over the anterior corner and pushing posteriorly and laterally until the anterior surface is flush
3. Confirm anatomic reduction fluoroscopically on AP and mortise views
4. Stabilize temporarily with a 1.6 mm K-wire in the middle to posterior aspect of the malleolus

Plate Application (Anti-Glide / Buttress)

1. For vertical shear (SAD) fractures: position the plate along the medial cortex of the distal tibia, spanning across the fracture apex
2. The plate acts as a buttress - fix proximal screws first into good metaphyseal bone (typically 3.5 mm cortical screws)
3. Distal fixation uses smaller screws (2.7-3.5 mm) into the malleolar fragment, angled to avoid joint penetration
4. Augment with cancellous lag screws parallel to the plafond if bone quality allows - two 3.5 mm fully threaded cortical screws placed 1 cm proximal and parallel to the tibial plafond provide the stiffest construct under transverse loading
5. Confirm no intra-articular screw penetration on AP fluoroscopy - use the view collinear with the medial joint space (frontal sign of the talus); an internally rotated mortise view will not demonstrate this clearly
6. ⚠️ Avoid screw insertion in the posterior colliculus - cadaveric studies show tendon abutment in all specimens and tendon damage in 50%

Hook Plate Application

1. Longitudinal incision over the central aspect of the malleolus, appropriately sized for plate length
2. Clear and refresh fracture site; reduce and temporarily stabilize with K-wire or lobster claw clamp
3. Select appropriate hook plate size
4. Press the plate onto bone, allowing the two distal prongs to engage under the tip of the malleolus
5. Pre-drill with 2.0 mm K-wires if bone is hard or severely comminuted
6. Fix proximal plate holes with cortical screws into the tibia
7. Optional: insert end cap over hooks to protect soft tissue

Final Checks

• Confirm full range of ankle motion
• Check reduction and implant position on AP, lateral, and mortise fluoroscopic views
• Wound closure in layers
• Immobilize in below-knee back-slab initially

Biomechanical Evidence

• The biomechanical literature is conflicting - no single construct dominates across all loading conditions
• No high-quality clinical RCT directly comparing screws vs. plate for medial malleolar fractures currently exists

Order of Fixation in Bimalleolar/Trimalleolar Fractures

• Standard approach: fix the lateral malleolus (fibula) first, then the medial malleolus
• Exception: if the lateral malleolus is severely comminuted, overreduction in the coronal plane can block medial malleolar reduction - in this case, fix the medial malleolus first

Complications

Summary: Fixation Selection Guide

Fragment size / bone quality assessment
        |
Large fragment + good bone → 1 or 2 lag screws (cancellous/cortical)
        |
Small fragment → Hook plate or TBW
        |
Vertical fracture line (SAD) → Anti-glide / buttress plate ± parallel screws
        |
Comminuted / osteoporotic → Hook plate or TBW (± washers)
        |
Failed screw purchase → Convert to plate

• Rockwood and Green's Fractures in Adults, 10th ed. 2025 - "Medial Malleolar Fixation" (pp. 3324-3325)
• Campbell's Operative Orthopaedics, 15th ed. 2026 - Technique 59.1
• Acumed Ankle Plating System 3 Surgical Technique Guide
• Paragon 28 Gorilla Ankle Fracture 360 Surgical Technique Guide