What is patellofemoral instability?

Patellofemoral instability refers to the kneecap (patella) slipping out of its normal position, often leading to dislocation. It commonly affects young adults, athletes, and individuals with joint hypermobility or alignment issues.

What causes the kneecap to dislocate?

Kneecap dislocation can result from trauma, twisting injuries, or anatomical factors such as a shallow trochlear groove or poor patellar alignment. It is more common in active individuals and those with ligament laxity.

How is patellofemoral instability diagnosed?

Diagnosis involves clinical examination and imaging such as X-rays, 3T MRI, or CT scans to assess bone structure, cartilage damage, and alignment. Professor Chinmay Gupte performs a full biomechanical assessment during your consultation.

Do I need surgery for a dislocating kneecap?

Not always. Many first-time dislocations can be treated with physiotherapy. Surgery is recommended for recurrent dislocations or if imaging shows structural issues like ligament rupture or bone misalignment.

What surgeries can help stabilise the kneecap?

Procedures include MPFL reconstruction, trochleoplasty, tibial tubercle osteotomy, or lateral release, depending on the patient’s anatomy and dislocation severity. Professor Gupte tailors surgery based on each individual case.

What is a children's ACL injury?

A children's ACL injury refers to a tear of the anterior cruciate ligament in the knee, often caused by sports-related activities. In children, these injuries must be managed carefully to avoid damage to the growth plates.

How is ACL surgery different in children?

Children require growth-sparing ACL reconstruction techniques, such as all-epiphyseal or partial transphyseal methods, to protect open growth plates and ensure proper bone development.

Does every child with an ACL tear need surgery?

Not always. Some children can be managed with physiotherapy and activity modification. Surgery is recommended for ongoing instability or high-risk sports involvement.

What is the recovery time after paediatric ACL surgery?

Recovery typically takes 9 to 12 months, including physiotherapy, rehab milestones, and return-to-sport clearance under specialist guidance.

Who is the best children’s ACL surgeon in London?

Professor Chinmay Gupte is a highly experienced consultant orthopaedic surgeon specialising in children’s ACL injuries. He offers expert, growth-sparing ACL surgery at the Sportshealing Clinic in London.

Children’s ACL Injury UK | Growth & Treatment Guide

Introduction

Anterior cruciate ligament (ACL) injuries in children and adolescents have increased substantially across the UK and in the world over the past decade.

Contributing factors include:

Early sport specialisation
Year-round competition
Increased intensity in academy-level sport with less rest periods
Greater participation of girls in pivoting sports often with poorer facilities
Better access to MRI enabling earlier diagnosis when suspected

Unlike adult ACL injuries, paediatric ACL tears must be managed with consideration of:

Open growth plates
Long-term bone joint development
Secondary meniscal injury risk
Psychological impact of stopping playing sport in children, whose whole identity as school may be affected by this.

This guide explains:

How ACL injuries present in children
How diagnosis differs from adults
Growth plate considerations
Surgical versus non-surgical management
NHS versus private pathways in the UK
Long-term joint protection

The objective is precision management that protects both growth and cartilage and restores children to playing the sports they love to play.

Why are Children’s ACL Injuries increasing?

Several epidemiological trends are clear:

IIncreased exposure to high-risk cutting sports
Higher training frequency and intensity
Improved diagnostic awareness with availability of MRI knee scans
Greater participation of young females in pivoting sports, often with poorer training regimes and facilities

Girls aged 13–17 show particularly elevated risk. Although exact causes remain unclear, this may be due to:

Neuromuscular control patterns
Hormonal influences
Biomechanical valgus tendencies
Poorer pitch and training facilities and the “gendered environment”

This is now a recognised UK public health concern in youth sport.

What are the signs of ACL injury in children and teenagers?

Typical features:

Twisting injury with foot planted not the ground or with ski not releasing
Audible “pop”
Immediate swelling within hours
Instability or giving way
Reduced confidence in pivoting
Children may under-report instability.

Recurrent swelling after sport is a key indicator.

How do you diagnose a child’s ACL injury?

Clinical Examination

Includes:

Lachmann and anterior drawer test child

Lachman test
Pivot shift
Effusion assessment

Examination can be difficult in anxious adolescents.

MRI Imaging

MRI confirms:

ACL rupture
Meniscal tears
Cartilage injury
Bone bruising
High-quality imaging is essential. To book an MRI click here

Delayed imaging risks missing meniscal tears.

Growth Plate Considerations

Children have open physes (growth plates) around the knee at:

Distal femur
Proximal tibia

Traditional adult ACL reconstruction techniques risk physeal injury if not modified.

Excessive damage to the growth plates may cause:

Growth disturbance
Limb length discrepancy
Angular deformity

Specialised paediatric ACL techniques are required.

Non-Surgical Management of children and teenagers’ ACL injuries

Historically, some children were treated with bracing and physiotherapy alone.

However, evidence shows:

High rates of recurrent instability after return to sport
Higher rates of meniscal injuries in non surgically treated children who return to sport
Secondary meniscal tears
Accelerated cartilage damage

Non-operative management may be appropriate in:

Low-demand children
Partial tears
Skeletally near-mature adolescents

But unstable pivoting athletes often require reconstruction.

Surgical Options in Children

1. Physeal-Sparing Techniques

Avoid drilling across growth plates.

Used in younger children with significant growth remaining.

2. Transphyseal Reconstruction

Carefully placed tunnels across physes.

Safe when performed with precision and appropriate technique.

Often used in adolescents approaching skeletal maturity.

Allograft is generally avoided in young high-demand patients due to higher failure risk.

Risks of Delayed Surgery

Delayed stabilisation may increase:

Medial meniscal tears
Meniscal root injury
Cartilage damage
Early osteoarthritis risk

Each episode of instability can cause secondary damage.

Timely assessment protects the joint.

NHS vs Private Pathways for children’s ACL injuries in the UK

NHS

* Free at point of care

* Regional paediatric specialist centres

* Waiting times vary

Private

Faster access
Direct consultant continuity
Typical cost range: £10, ,000–£18,000

Paediatric expertise matters more than setting.

Rehabilitation After Surgery

Rehabilitation is structured and gradual:

Protected early phase
Progressive strengthening
Neuromuscular retraining
Objective return-to-sport testing
Return to pivoting sport typically:

9–12 months minimum.

Too Early a return increases re-rupture risk.

Risk of Re-Injury in Young Athletes

Adolescents have higher rates of:

Graft re-rupture
Contralateral ACL injury ie injury to the other knee (10-20%)
For an example of a typical children’s ACL rehab program click here

Prevention programmes must continue after surgery.

Time alone does not confer readiness.

Objective strength symmetry and movement quality are essential.

Psychological Considerations

ACL injury in teenagers can lead to:

Anxiety about return
Loss of athletic identity
Reduced confidence

Integrated psychological support improves outcomes.

Long-Term Implications

ACL injury before adulthood increases risk of:

Meniscal deficiency
Cartilage thinning
Early osteoarthritis
Joint preservation strategy must begin at first injury.

Decision Framework for Parents

Ask:

1. Is the knee unstable?

2. Is the child involved in pivoting sport?

3. Are growth plates open?

4. Is there meniscal damage?

5. What surgical technique protects growth?

6. Is it a partial or complete ACL injury?

7. What are the risks of surgical and non surgical management.

Early specialist paediatric evaluation is essential.

Here is an expert consensus statement

Frequently Asked Questions

Is ACL surgery safe in children?

Yes, when performed using growth-aware techniques by experienced paediatric knee surgeons.

Can children return to competitive sport?

Many do, but structured rehabilitation and objective return criteria are critical.

What happens if surgery is delayed?

Repeated instability episodes may increase meniscal and cartilage damage.

Conclusion

Children’s ACL injuries require specialised assessment.

Management must balance:

Growth plate protection
Joint stability
Cartilage preservation
Safe return to sport

Early precision reduces long-term risk.