Key takeaway
Elastic nailing femur fixation, also called elastic stable intramedullary nailing or flexible intramedullary nailing, is mainly used in children with femoral shaft fractures, not as a routine adult femur fixation method. Current orthopedic guidance places it most clearly in school-age children with diaphyseal femur fractures, especially length-stable patterns where two flexible nails can share load and help maintain alignment during healing.
It is not a universal solution. Age, body weight, fracture level, fracture stability, soft-tissue condition, associated injuries, and surgeon assessment all influence whether elastic nails, submuscular plating, external fixation, spica casting, or rigid trochanteric-entry nailing is the better option.
This overview is for educational use by readers following fracture fixation topics. It is not a substitute for evaluation by a pediatric orthopedic trauma specialist.
What elastic nailing of the femur means
Elastic nailing uses flexible metal nails placed inside the medullary canal of the femur. In pediatric femoral shaft fractures, the construct usually uses two nails inserted from separate entry points. Their prebent shapes create opposing elastic forces that support the fracture from inside the bone.
This is different from the locked rigid intramedullary nail commonly used for many adult femoral shaft fractures. Elastic nails usually do not lock with screws at both ends. Their stability depends on nail size, nail contour, balanced opposing forces, fracture pattern, bone quality, and postoperative protection.
The technique is also described as ESIN, TENS, FIN, or flexible intramedullary nailing. In practical search language, elastic nailing femur often refers to titanium elastic nails used for pediatric femoral shaft injuries. The target injury is usually a diaphyseal fracture, meaning a fracture through the shaft region rather than the femoral neck, femoral head, or joint surface.
Because children have open growth plates, thick periosteum, and greater remodeling potential than adults, fixation choices cannot simply be transferred from adult trauma algorithms. Pediatric treatment has to balance fracture stability with growth preservation, nursing care, pain control, return to mobility, implant-related irritation, and the possible need for later implant removal.
Where current evidence places elastic nails
The American Academy of Orthopaedic Surgeons adopted an updated evidence-based clinical practice guideline on pediatric diaphyseal femur fractures on August 24, 2026. In that guideline, strong evidence supports flexible intramedullary nailing for children aged five to eleven years with diaphyseal femur fractures. The 2026 update added newer study findings to the elastic intramedullary nail recommendation and reported that the updated literature search extended through March 10, 2026.
The Pediatric Orthopaedic Society of North America describes treatment selection as dependent on age, weight, fracture stability, mechanism, and associated injuries. Its educational material places flexible intramedullary nailing among the options for children around five to eleven years old, particularly when the child is under about 49 kg and the fracture is length-stable. It also notes that unstable oblique or comminuted patterns can be harder to control with flexible nails and may be better suited to plating, external fixation, or rigid nailing in selected older patients.
| Clinical factor | Why it matters | Common implication |
|---|---|---|
| Age five to eleven years | This is the age range most clearly supported in AAOS guidance for flexible intramedullary nailing of diaphyseal femur fractures. | Elastic nails are often considered when the fracture pattern is suitable. |
| Weight near or above 49 kg | Heavier children place greater mechanical demand on flexible constructs. | Submuscular plating or rigid trochanteric-entry nailing may be considered, especially in older children. |
| Length-stable transverse or short oblique fracture | The construct can better maintain length and alignment. | Elastic nails may be a strong candidate option. |
| Length-unstable, comminuted, long oblique, proximal, or distal pattern | Flexible nails may provide less reliable control of shortening, angulation, or rotation. | Plating, external fixation, or rigid nailing may be favored depending on age and injury context. |
| Polytrauma or open injury | Soft-tissue condition and damage-control priorities may dominate implant choice. | External fixation or staged fixation may be considered. |
Why fracture stability is the central decision point
Elastic nails work best when the fracture pattern allows the nails to act as an internal splint without losing length or rotation. A simple transverse fracture is usually considered length-stable. Short oblique fractures may also be manageable in selected patients.
Long oblique, spiral, multifragmentary, or comminuted fractures are more likely to be length-unstable. In these patterns, the bone fragments can telescope, shorten, rotate, or angulate despite internal support.
This distinction is one reason elastic nailing should not be presented as the answer for every pediatric femur fracture. A technically correct nail insertion can still underperform if the mechanical environment is wrong. Conversely, a length-stable fracture in the appropriate age and weight range may benefit from a smaller-incision approach, internal stabilization, and earlier mobility compared with prolonged traction-based care.
Fracture location also matters. Proximal-third and distal-third shaft fractures may be harder to control because the nail geometry provides less balanced support near the ends of the femur. AO Surgery Reference describes retrograde ESIN as a way to manage certain shaft fractures and emphasizes alignment, rotation checks, and appropriate nail configuration. For non-surgeon readers, the practical point is that elastic nailing is a biomechanical strategy, not simply the insertion of a thin rod.
Technical principles that influence results
Published surgical references consistently describe several principles behind successful elastic nailing. The nails should be appropriately sized for the canal, generally with each nail occupying a meaningful proportion of the narrowest canal diameter. The two nails should usually be the same diameter so their bending forces are balanced. Nail contouring is intended to create three-point fixation and resist angulation.
AO Surgery Reference notes that nail diameter is commonly selected between 33% and 40% of the narrowest medullary canal, with both nails of equal diameter. It also emphasizes careful rotational assessment before final fixation and notes that end caps can increase axial stability and protect soft tissues in selected cases.
These details are clinically important. Undersized nails, unbalanced bends, excessive nail crossing, or poor end management can contribute to irritation, loss of reduction, malalignment, or later removal problems.
Elastic nails are commonly inserted away from the fracture site, often retrograde from the distal femur for shaft patterns, using imaging during the procedure. The fracture is usually reduced closed if possible, although limited open reduction may be required when alignment cannot be achieved. Final imaging and clinical rotation comparison are important because rotational malalignment does not remodel as predictably as some angular deformities in children. See also: Implants.
Complications and follow-up issues
Elastic nailing is widely used, but it is not risk-free. Reported complications include soft-tissue irritation at nail entry sites, pain from prominent nail ends, nail migration, superficial or deep infection, delayed union or loss of alignment, angular deformity, limb-length difference, malrotation, refracture after implant removal, and the need for an unplanned return to the operating room. POSNA notes that complication rates reported in studies of flexible intramedullary nailing vary widely, partly because studies define and count complications differently.
Some complications are closely related to the construct. Prominent nail ends can irritate skin and soft tissue around the knee. Excessively advanced nails can create risks near the proximal femur. Inadequate rotational control can leave a child with a clinically relevant torsional difference. In heavier children or unstable fracture patterns, flexible nails may not provide enough axial or rotational stability, making patient selection essential.
Aftercare varies by fracture and surgeon protocol. AO Surgery Reference describes early ambulation with crutches, protected weight bearing in many cases for the first several weeks, clinical and radiographic follow-up until healing and function are restored, and later assessment of leg length and alignment. It also notes that symptomatic implants can be removed after complete fracture healing, commonly in the six- to twelve-month period following injury. These time frames are not universal instructions; they show why follow-up continues well beyond the day of surgery.
How elastic nailing compares with common alternatives
For infants and younger children, nonoperative treatment such as Pavlik harness or spica casting may be appropriate because of rapid healing and remodeling potential. For many children between six months and five years, spica casting remains an important option, especially when shortening is limited and family care demands can be managed. Elastic nailing becomes more prominent as children get older, larger, and less suitable for spica-based management.
Submuscular plating provides stronger control for certain length-unstable, proximal, distal, or heavier-patient patterns. It may reduce issues such as soft-tissue irritation from nail ends or angular deformity in specific comparisons, but it often involves more exposure, greater blood loss, and a plate that may be more involved to remove. Recent systematic reviews comparing ESIN and plating generally show that neither method is universally superior; each has a different complication profile and works best in different fracture contexts.
External fixation can be useful for open fractures, polytrauma, severe soft-tissue injury, or damage-control situations. It is less commonly the preferred routine option for a closed, length-stable fracture when internal options are appropriate, because pin-tract issues and refracture concerns can be relevant.
Rigid intramedullary nailing is generally considered for older or larger children and adolescents. However, modern pediatric practice avoids piriformis or near-piriformis entry in skeletally immature patients because of femoral head blood-supply concerns. The AAOS guideline specifically identifies rigid trochanteric-entry nailing, submuscular plating, and flexible intramedullary nailing as options for children aged eleven years to skeletal maturity, while excluding piriformis or near-piriformis entry rigid nailing.
Questions that help define the right fixation plan
When elastic nailing is being considered, the key question is not simply whether the implant is available. The clinical team needs to decide whether the fracture biology and mechanics match the method. Useful questions include:
- Is the fracture truly diaphyseal, or does it extend into the subtrochanteric, metaphyseal, or joint region?
- Is the pattern length-stable, or is there comminution, long obliquity, or segmental injury?
- What are the child’s age, skeletal maturity, and body weight?
- Are there open wounds, vascular injury, head injury, or other fractures that change treatment priorities?
- How will rotation, limb length, and alignment be checked after fixation?
- What is the expected weight-bearing plan, follow-up schedule, and implant removal policy?
These questions keep the discussion focused on clinical suitability rather than on the implant category alone. Elastic nailing can be an efficient, growth-conscious fixation method when used in the right patient, but it can be mechanically underpowered in the wrong fracture pattern.
Frequently asked questions
Is elastic nailing of the femur mainly for children?
Yes. In common orthopedic usage, elastic nailing of the femur mainly refers to pediatric femoral shaft fixation. Adult femoral shaft fractures are more often treated with locked rigid intramedullary nails or other fixation strategies, depending on the injury.
What age group is most supported by guidelines?
The clearest AAOS recommendation supports flexible intramedullary nailing for children aged five to eleven years with diaphyseal femur fractures. Children outside that range require individualized decision-making based on size, skeletal maturity, fracture pattern, and associated injuries.
Does elastic nailing always require later removal?
Implant removal practices vary. Elastic nails may be removed after the fracture is completely healed, particularly if the nail ends cause pain or irritation. Some references describe removal of symptomatic implants around six to twelve months after injury, but timing should be set by the treating surgeon.
Why might a surgeon choose a plate instead of elastic nails?
A plate may be preferred when the fracture is length-unstable, very proximal or distal, comminuted, or in a heavier child where elastic nails may not control shortening, angulation, or rotation reliably. Plating has its own tradeoffs, including greater exposure and potential removal complexity.
Is elastic nailing the same as rigid intramedullary nailing?
No. Elastic nails are flexible, usually used in pairs, and rely on balanced elastic forces. Rigid intramedullary nails are stiffer implants commonly used in adults and selected adolescents. In skeletally immature patients, entry point selection for rigid nails is important because certain entry points can endanger the blood supply to the femoral head.