What is the ideal time to remove a TENS (Tibial External Nail System) nail in a pediatric tibia fracture?

Timing of TENS Nail Removal in Pediatric Tibia Fractures

TENS nails in pediatric tibial fractures should be removed after radiographic and clinical union is achieved, typically at 11-16 weeks post-operatively, with the procedure ideally performed before symptomatic hardware irritation develops but after complete fracture consolidation.

Evidence-Based Timing Recommendations

Standard Union Timeline

• Average union time ranges from 10.85 to 16.1 weeks across multiple studies of pediatric tibial fractures treated with TENS 1, 2, 3
• The most recent comprehensive study reported mean union time of 11.17 ± 2.81 weeks for TENS fixation in pediatric tibia fractures 2
• Young children (up to 10 years) demonstrate mean union at 16.1 weeks (range: 11-26 weeks), even with open fractures 3

Clinical Decision Algorithm for Removal

Step 1: Confirm Complete Union (Minimum 11-12 weeks)

• Verify both radiographic union (bridging callus on at least 3 cortices) and clinical union (pain-free weight bearing) 1, 2
• Do not remove hardware prematurely, as this increases re-fracture risk 2

Step 2: Assess for Hardware-Related Complications

• Nail prominence and skin irritation occurs in 13.6% of cases and may necessitate earlier removal after union 2
• Painful bursitis at entry points develops in 14.2% of patients and requires earlier nail removal 4
• Superficial soft tissue discomfort from prominent TEN tips affects some patients and may require cutting the tip before union or removing after union 3

Step 3: Timing Window

• Optimal removal window: 12-20 weeks post-operatively for uncomplicated cases 1
• Earlier removal (after confirmed union) is appropriate if symptomatic hardware irritation develops 4, 3
• Delayed removal beyond 6 months is acceptable but increases risk of hardware-related symptoms 2

Important Clinical Considerations

Factors Affecting Union Time

• Open fractures do not significantly delay union time in young children when treated with TENS, though complication rates are higher 1, 4
• Age under 10 years shows reliable union even with grade III open fractures, averaging 16 weeks 3
• Closed fractures in school-age children (mean age 8.9 years) unite at approximately 10.85 weeks 1

Common Pitfalls to Avoid

Do not remove nails before complete union - One study reported a re-fracture case, emphasizing the importance of confirmed consolidation 2

Monitor for infection - Superficial infections at nail entry sites occur in 4.4-22.2% of cases and should be treated with antibiotics before hardware removal 1, 2, 4

Address hardware irritation proactively - If symptomatic nail prominence develops before union, consider cutting the extraosseous portion rather than complete removal 3

Special Circumstances

• Combined fixation methods (TENS with external fixation pins) show no increased complications and may allow standard removal timing 4
• Delayed union (defined as >20 weeks) occurs in 8.8% of cases and requires extended retention of hardware until solid union 2
• Limb length discrepancies (occurring in 6.6-11.1% of cases) should be documented before hardware removal for future monitoring 2, 4

Practical Removal Protocol

Hardware removal should occur as an outpatient procedure after:

1. Minimum 11-12 weeks post-fixation
2. Radiographic evidence of bridging callus
3. Pain-free full weight bearing
4. Resolution of any active infection
5. Patient/family counseling about activity restrictions for 2-4 weeks post-removal to prevent re-fracture 1, 2