Courtesy: Shital Parikh, Taral Nagda, Ashok Shyam, IORG, OrthoTV

 

TENS (Titanium Elastic Nailing System) – Complications & Pitfalls

Wrong Fracture Selection

• Avoid TENS in length-unstable fractures.
• Long oblique, spiral, comminuted, and segmental fractures are poor indications.
• Failure may result in shortening and loss of reduction.
• Shortening up to 2 cm is considered acceptable in the source.
• Around 2 cm shortening may cause functional problems such as a limp.

Management of Loss of Reduction

• Early failure within weeks may require re-nailing with a more stable construct.
• Bridge plating may be required.
• External fixation is another option.

Ideal Indications for TENS

• Diaphyseal fractures.
• Length-stable fractures.
• Femur fractures in children younger than 11 years.
• Femur weight limit: less than 50 kg.

Fractures Where TENS Is Not Ideal

• Proximal or subtrochanteric fractures.
• Distal or supracondylar fractures.
• Comminuted fractures.

Special Fracture Locations

• Subtrochanteric femoral fractures have a high complication rate, approximately 22%.
• Complications include malunion, nail migration, and limb length discrepancy.
• Supracondylar femoral fractures require antegrade nailing according to the source.
• Complications include trochanteric nail irritation and infection.

Nail Configuration

• Avoid nails crossing repeatedly.
• Nails should cross only twice, proximally and distally.
• Maximum separation between the nails should be present at the fracture site.
• The two nails should provide symmetrical and opposing forces.

Forearm Nail Direction

• Radius nail should point toward the ulna.
• Ulna nail should point toward the radius.
• This helps maintain the interosseous space.

Nail Size

• Both nails should be of equal diameter.
• For the femur, each nail should be approximately 40% of the canal diameter.
• For the forearm, each nail should be approximately two-thirds of the canal diameter.

Narrow Canal

• A canal smaller than 2 mm can make insertion difficult.
• Forceful insertion can cause nail jamming, physeal injury, and fracture-site distraction.
• Allow muscle relaxation before attempting further insertion.
• Rotate and reinsert the nail if necessary.
• Use a smaller nail when required.
• The nail can be cut shorter if appropriate.

Titanium vs Stainless Steel

• Titanium is easier to insert and more elastic.
• Titanium has a higher risk of malunion according to the source.
• Stainless steel is more rigid and has a lower risk of malunion.
• Stainless steel is harder to insert and may increase the risk of comminution.

Open Reduction

• Open reduction increases the risk of delayed union.
• It may also increase nonunion and refracture.

Floating Injuries

• Combined femur and tibia fractures have a high complication rate.
• Valgus deformity, limb length discrepancy, and growth arrest may occur.
• Management of growth-related problems may include growth modulation, epiphysiodesis, or corrective procedures.

Iatrogenic Complications

• Cortical perforation may occur during nail insertion.
• Entry-site fracture can occur.
• Multiple entry holes weaken the cortex.
• Use a single appropriate entry point.
• A nail may miss the distal fragment and result in fixation failure.
• Always confirm nail position with orthogonal AP and lateral views.
• Incorrect nail direction may cause nerve irritation, including sciatic nerve irritation.

Nail Prominence

• Nail prominence is a very common complication.
• It can cause skin irritation, infection, bursitis, and osteomyelitis.
• Excessive bending of the nail can contribute to prominence.
• Keep the nail flush with the cortex.
• Avoid excessive bending.

Nail Length

• A nail that is too long may irritate the opposite cortex or the joint.
• A nail that is too short may provide inadequate stability.
• If necessary, withdraw the nail slightly, cut it, and re-impact it.

Nonunion and Refracture

• These are more common following open reduction.
• They are also more common in tibial fractures.
• Treatment may include plating or modified re-nailing.

Nail Removal

• The source recommends removal at approximately 6 months after union.
• Delayed removal may result in the nail becoming buried because of growth.
• Delayed removal can make extraction difficult and may interfere with future surgery.
• The source advises against routine removal in pathological fractures and osteogenesis imperfecta.

When to Abandon TENS

• Inability to pass the nails.
• Persistent fragment instability.
• Displacement of a butterfly fragment.
• Always have a Plan B.
• Options include plating or external fixation.

Exam Pearls

• Best indication: Diaphyseal, length-stable fracture.
• Avoid: Comminuted, proximal, and distal fractures.
• Femur nail size: Approximately 40% of canal diameter per nail.
• Two nails: Symmetrical and opposing forces.
• Always check: AP and lateral views.
• Most common complication: Nail prominence.
• Major complications: Malunion and limb length discrepancy.