Injuries & Sport

Tibial spine avulsion fracture in children

Name: Tibial Spine Fracture in Children: Diagnosis and Treatment
Creator: Dott. Daniele Priano
Published: 2026-08-01

The paediatric equivalent of an ACL injury: the ligament stays intact but avulses a bony fragment from the tibial plateau. Treatment depends on how far the fragment is lifted.

Medically reviewed: August 2026·Dott. Daniele Priano

What to do now

This chart does not replace a medical visit and does not allow a diagnosis at a distance.

After a knee injury, the most useful practical criteria for a family are how quickly swelling appears and whether the child can put weight on the leg.

Today / right away

Knee swelling within a few hours of the injury
Inability to bear weight or to walk
Knee locked and unable to straighten
Visible deformity, open wound, cold or tingling leg

Go to the emergency department: an early X-ray is needed.

Within a few days

Pain persisting beyond a few days despite rest
The knee swells again when activity is resumed
X-ray reported as normal but pain not improving
A sense of giving way or instability

Ask for a paediatric orthopaedic assessment within a few days, bringing any imaging already performed.

Check-up that can be scheduled

Injury already assessed and documented, pathway under way
Recovery ongoing but questions about movement, weight-bearing or return to sport

Plan an orthopaedic review to check range of motion, strength and return criteria.

This chart does not replace a medical examination and does not allow a diagnosis at a distance.

Quick Answers

Is a tibial spine fracture the same as an ACL tear?

Not exactly. The anterior cruciate ligament stays intact but detaches from the bone, taking a fragment of the tibial plateau with it. It is regarded as the paediatric equivalent of an ACL injury because mechanism and functional consequences are similar, but treatment differs: here the bony insertion is restored rather than the ligament reconstructed.

What is the Meyers-McKeever classification?

It is the most widely used radiographic classification. Type I is an undisplaced fragment; type II a fragment lifted anteriorly but still hinged posteriorly; type III a completely displaced fragment; type IV a comminuted or rotated fragment. The type largely determines the choice between conservative and surgical treatment.

When is surgery required?

Generally when the fragment cannot be reduced or does not stay reduced: irreducible type II, type III and type IV. The aim is to restore the bony insertion of the anterior cruciate ligament and prevent the lifted fragment from blocking extension. The surgical options are described on the dedicated page.

See all 6 questions →

In children and adolescents with open growth plates, the bone of the intercondylar eminence — the small ridge of the tibial plateau where the anterior cruciate ligament attaches — is weaker than the ligament itself. A twisting or hyperextension injury of the knee, typical of a fall from a bicycle or a sporting collision, tears the ligament in an adult; in a child it avulses a bony fragment instead. The ligament remains intact, but its anchorage lifts off: this is a tibial spine (eminence) fracture, considered the paediatric equivalent of an ACL injury.

The typical picture is a knee that swells rapidly within a few hours of the injury (haemarthrosis, blood inside the joint), with pain, inability or marked difficulty in weight bearing, and limited extension — especially when the lifted fragment acts as a mechanical block. One practical point: a knee that swells within hours of an injury in a child is never a trivial finding and always deserves an orthopaedic assessment.

The good news is biological: here bone must heal, not ligament, and bone usually unites in 6-8 weeks. The pathway depends on fragment displacement according to the Meyers and McKeever classification and on whether an anatomical reduction can be obtained. The risk to keep in mind is not so much failure of healing but joint stiffness, which is why restoring motion is planned and monitored from the outset. For the wider picture of joint injuries during growth see also knee injuries in children and adolescents and paediatric sports injuries.

When to seek evaluation

Knee that swells rapidly (within hours) after a twisting or hyperextension injury
Inability or marked difficulty in weight bearing after the injury
Loss of full knee extension or a sense of blocking
Deep knee pain with a feeling of giving way
X-ray already performed showing a bony fragment lifted from the tibial plateau
Persistent pain beyond a few days even when the X-ray was reported as normal

What is evaluated

Injury history and presence of joint effusion (haemarthrosis)
Active and passive extension and flexion, looking for a mechanical block
Anterior cruciate stability tests (Lachman) compared with the opposite knee
X-ray in two views: identifies and classifies the fragment
MRI when menisci, cartilage or associated ligament injuries need assessment, or when the X-ray is not conclusive
CT in selected cases, when comminution must be defined precisely or fixation planned

Treatment options

Type I (undisplaced fragment): conservative treatment with immobilisation in extension or slight flexion and close radiographic follow-up
Reducible type II: conservative treatment after reduction, with radiographic confirmation that reduction is maintained
Irreducible type II, type III and type IV: surgical reduction and fixation, usually arthroscopic
Planned rehabilitation after conservative or surgical treatment, with gradual recovery of motion and load according to union
Clinical and radiographic follow-up until bony healing and, in growing patients, surveillance of limb growth

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When Surgery Is Needed

When the fragment remains lifted or cannot be reduced, treatment is surgical: the fragment is returned to its anatomical bed and stabilised, restoring the bony insertion of the anterior cruciate ligament while protecting the growth plate.

🔗View surgical options for this condition →

Frequently Asked Questions

Is a tibial spine fracture the same as an ACL tear?▼

What is the Meyers-McKeever classification?▼

When is surgery required?▼

Is MRI always needed?▼

No. A two-view X-ray is the starting examination and is often enough to classify the injury. MRI is useful when associated meniscal, cartilage or ligament injuries are suspected, or when the X-ray does not clarify the picture. CT is reserved for selected cases where the fragment anatomy must be defined precisely.

How long before returning to sport?▼

Bone usually unites in 6-8 weeks, but return to sport depends on recovery of motion, strength and knee control. In typical pathways running is reintroduced around months 3-4 and contact or pivoting sport later, with functional criteria verified. The detailed rehabilitation protocol describes phases and criteria.

Can any problem remain after healing?▼

After correct bony healing the knee is usually stable. Mild anterior laxity may remain — measurable but often without practical consequences — because the ligament had already stretched at the time of injury. The main issue to prevent is stiffness, which is why follow-up in the first weeks focuses on recovery of motion.

Important Notice: The information on this page is for educational and informational purposes only and does not constitute medical advice. Each clinical case is unique: the appropriate treatment is determined during the specialist consultation, based on a thorough clinical examination and, where necessary, diagnostic imaging. For any doubts or concerns, please consult a specialist.