Tibial Fractures Pediatric

The tibia is the second most common paediatric long-bone fracture, accounting for about 15% of all paediatric fractures. Incidence peaks in toddlers and in adolescents. Boys are affected more than girls, about 2:1, and left and right equally.

Mechanism. Each pattern has its own:

• Toddler's fracture - a low-energy twist or fall
• Proximal metaphyseal fracture - direct impact
• Tibial spine fracture - hyperextension, classically off a bicycle
• Shaft fracture - a direct blow or torsion
• Floating knee - high energy (for example a motor vehicle accident)

The physes. The proximal tibial physis contributes 57% of tibial length and the distal physis 43%, so injuries to the proximal physis have greater potential for growth disturbance.

Where they lie. The proximal physis lies 1-2 cm distal to the joint line and is protected by the tibial tubercle apophysis. The distal physis closes asymmetrically: central, then medial, then lateral.

The tubercle apophysis is a secondary ossification centre, vulnerable during adolescence (Osgood-Schlatter).

Blood supply. The nutrient artery enters the posterior cortex at the junction of the proximal and middle thirds and supplies the inner two-thirds of the cortex. Periosteal vessels supply the outer third, and they are more robust in children, so healing is better.

The popliteal trifurcation. The proximal tibia is a vulnerable area at the trifurcation: watch for vascular injury with displaced proximal fractures.

Soft tissues. The anteromedial tibia is subcutaneous, with minimal soft-tissue cover, which brings a risk of open fractures and wound complications. The leg has four compartments, and children can develop compartment syndrome.

The periosteum is thick in children; it helps maintain reduction and contributes to rapid healing.

Toddler's fracture. CAST, the Childhood Accidental Spiral Tibial fracture: a non-displaced spiral or oblique fracture in a child of walking age, 9 months to 3 years, after a low-energy twist or fall. The distal tibial shaft is the most common site, and the fracture is often not visible on the initial radiograph.

Tibial spine fractures, the paediatric ACL equivalent, are classified by Meyers and McKeever. The intermeniscal (transverse) ligament can interpose and block reduction in Types II and III.

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Tibial shaft fractures are described by pattern (spiral, oblique, transverse, comminuted), by location (proximal, middle or distal third) and by stability. An isolated tibial fracture with an intact fibula is stable; a fracture of both bones, or one with significant displacement, is unstable. The intact fibula has its own cost: it may cause valgus malunion.

The toddler. The child limps or will not walk, refuses to bear weight, and has point tenderness over the tibia after a minor fall or twist. Swelling is often absent at first and the radiographs may be normal, so the diagnosis is clinical.

The tibial spine. Acute knee pain after hyperextension, often a bicycle handlebar injury, with a knee effusion (haemarthrosis) and an inability to extend the knee fully. Lachman is positive if tested.

The floating knee. A high-energy injury. Assess the ipsilateral hip, knee and ankle, and screen for head, chest and abdominal trauma. A neurovascular examination is essential.

Radiographs. AP and lateral views of the tibia and fibula, including the knee and ankle joints. For a suspected tibial spine fracture, AP and lateral views of the knee.

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The occult toddler's fracture. The first film may be negative. Look for subtle periosteal reaction at 10-14 days, and if clinical suspicion is high, a bone scan or MRI can confirm the fracture. A bone scan is rarely needed.

MRI is used for the occult toddler's fracture, for assessing a tibial spine fracture and for associated soft-tissue injury. CT is for surgical planning of a tibial spine fracture and for complex intra-articular fractures.

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The limping or non-weight-bearing child. A toddler refusing to weight-bear with a normal radiograph has a broad differential. The job is to separate a benign occult fracture from infection, malignancy and non-accidental injury before reassuring the family.

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A tibial fracture may be the first presentation of non-accidental (inflicted) injury, and recognising the red flags before reassuring or discharging a family is a non-negotiable safeguarding duty. The single most important discriminator is whether the child is developmentally able to have caused the injury.

Algorithm

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Age sets the strategy. The treatment principles by age:

• Under 6 years - a cast for most fractures; remodelling potential is high
• 6-10 years - a cast if the fracture is stable; operative treatment if it is unstable or acceptable alignment is not achieved (for an unstable shaft fracture, consider flexible nails)
• Over 10 years - remodelling potential is lower, and flexible IM nails are considered for shaft fractures

Toddler's FractureProximal MetaphysealTibial SpineShaft Fractures

Treat the clinical diagnosis. A long leg cast or walking boot for 3-4 weeks, even if the radiograph is negative. The fracture is non-displaced and needs no reduction. Healing is rapid at this age, and a follow-up radiograph at 2 weeks shows callus.

Acute treatment. A long leg cast for 4-6 weeks. Anatomic reduction is attempted but is not essential.

Cozen's phenomenon. Progressive valgus develops 6-18 months after injury, in a fracture that has healed, and peaks at 12-18 months (onset was between 8 and 19 months in the natural-history series under Evidence). The mechanism is unclear; asymmetric growth stimulation and tethering by the fibula are the explanations offered.

Natural history. In most cases the angle improves substantially by skeletal maturity, returning to about the limb's own post-treatment alignment. A small excess over the uninjured leg tends to remain, and roughly three-quarters of these tibiae also overgrow slightly.

What to tell the family. Remodelling is real but not predictable in the individual child, as the largest guided-growth series states plainly, so it is a reason to wait rather than a guarantee to hand the family. Full detail, including the guided-growth decision, is on the dedicated Cozen's fracture page.

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What not to do.

• Overcorrect into varus acutely
• Perform an osteotomy for the valgus: it is rarely indicated before maturity and has largely been abandoned even after it, because the valgus recurs. Guided growth is the modern choice when surgery is genuinely needed
• Promise the parents that deformity will not occur, or that the legs will end up identical

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By type. The Meyers-McKeever type decides the treatment:

• Type I - extension cast for 4-6 weeks, non-weight-bearing initially
• Type II - attempt closed reduction in extension; cast if it reduces, operate if the intermeniscal ligament blocks it
• Types III and IV - surgical fixation, open or arthroscopic, with suture or screw fixation

Rehabilitation. Range of motion after healing, then an ACL rehabilitation protocol. Fixation choice, arthrofibrosis and residual laxity are covered in depth on the dedicated tibial spine fractures page; for the ligament injury this fracture substitutes for, see paediatric ACL injury.

Under 6 years. A long leg cast, accepting up to 10 degrees of angulation and 1cm of shortening.

Over 10 years. For displaced fractures, flexible IM nails are preferred. Rigid nails are avoided because of the risk to the proximal tibial physis.

Both-bone fractures are more unstable, and the threshold for operative fixation is lower.

The acceptable-deformity thresholds are not arbitrary: they follow the predictable rules of physeal remodelling. Knowing why a deformity will or will not correct is what lets you justify closed treatment versus reduction in the viva.

The tibia is less forgiving than the femur. Overall it remodels less reliably, so coronal angulation is corrected less readily and rotation not at all. This is why the accepted limits tighten with age and are plane-dependent, and why a rotational malalignment must be corrected at the time of treatment rather than left to remodel.

Toddler's fracture. Excellent: complete healing in 3-4 weeks, with no long-term sequelae.

Proximal metaphyseal fracture. Good, despite Cozen's phenomenon. Expect the small residual valgus excess and mild overgrowth described under Management rather than a return to symmetry. See genu valgum and varum for how a residual coronal deformity is then assessed and, if needed, corrected.

Tibial spine fracture. Good outcomes with proper treatment. Residual ACL laxity is possible but usually not symptomatic.

Shaft fractures. Excellent, with high union rates and good remodelling potential in younger children.

The floating knee. Ipsilateral femur and tibia fractures from high-energy trauma, such as a motor vehicle accident or a fall from height. Associated injuries include knee ligament injuries in 40-80%, vascular injuries and other trauma, and the complication rate is higher.

Managing it. Both levels usually need surgical stabilisation: the femur typically with flexible nails, the tibia with a cast or nails depending on the pattern. It carries the highest risk of compartment syndrome, and a leg-length discrepancy is possible.

Pathological fractures. The fracture follows minimal trauma, and there may have been prior symptoms. Causes include simple bone cyst, fibrous dysplasia and osteogenesis imperfecta. Treat the fracture first, then address the underlying pathology, with curettage and bone grafting for cysts if needed.

Cozen's: predict or just watch? Age, sex and initial angulation do not reliably predict who develops late valgus, and the angle usually improves substantially, but it does not reliably resolve (see Natural history under Management). Routine prophylactic intervention is still not justified; the genuine debate is how long to observe before offering guided growth.

Tibial spine: suture, screw or anchor? Comparative data favour suture-based fixation for function and lower implant-removal rates, although in the meta-analysis under Surgical Technique the outcomes that measure the repair itself showed no difference. No high-quality randomised trial defines the optimal construct, and open versus arthroscopic reduction also remains debated.

The operative threshold in adolescents. The angulation and shortening a growing tibia will remodel is age-dependent and imprecise. Heavier, older adolescents behave more like adults, which narrows the case for purely closed treatment.

Imaging the occult toddler's fracture. MRI, bone scan and ultrasound can confirm occult fractures, but most authorities treat clinically without advanced imaging. The controversy is cost and radiation against diagnostic certainty.