Orthopaedic Surgery - Tibial Spine Fracture

Basics

A tibial spine fracture is an avulsion fracture involving the:

Intercondylar eminence of the proximal tibia.

It is also referred to as a:

Tibial eminence fracture.

Anatomy

The:

Anterior tibial spine

provides an important attachment site for the:

Anterior cruciate ligament.

Pediatric Mechanism

In the skeletally immature knee, the ACL may be stronger than the incompletely ossified:

Tibial spine.

Therefore, traumatic force may produce:

Bony avulsion of the tibial spine

rather than a midsubstance:

ACL tear.

ACL Injury in Children

Although tibial spine avulsion is characteristic of the immature knee, children can still sustain:

Midsubstance ACL tears.

Femoral Notch Anatomy

A relatively narrow:

Femoral intercondylar notch

may predispose some children toward:

Midsubstance ACL injury

rather than:

Tibial spine avulsion.

Classification

The classic:

Meyers and McKeever classification

is based primarily on the degree of:

Fracture displacement.

Type I

Type I is:

Minimally displaced or essentially nondisplaced.

The fragment remains near its normal:

Anatomic position.

Type II

Type II is a:

Hinged fracture.

The anterior portion of the fragment is elevated while the posterior portion remains attached, creating an intact:

Posterior hinge.

Type III

Type III demonstrates:

Complete separation of the fragment

with:

Upward displacement

and often:

Rotation.

Epidemiology

Tibial spine fractures are considerably more common in:

Children

than in adults.

Incidence

Historical data suggest that these fractures occur approximately:

Four times more often in children than adults.

Etiology

The injury usually results from forces that tension the:

ACL.

Common Mechanisms

Mechanisms include:

Twisting injury

Varus-valgus stress

and

Hyperextension.

Typical Causes

Common causes include:

Bicycle falls

Athletic injuries

and

Motor vehicle collisions.

Diagnosis

Diagnosis is based on:

Traumatic history

Physical examination

and

Imaging.

Signs and Symptoms

Patients usually report:

Knee pain

after trauma.

Weight Bearing

The patient often refuses or is unable to:

Bear weight.

Swelling and Hemarthrosis

Typical findings include:

Knee swelling

Effusion

and

Hemarthrosis.

Loss of Extension

The patient may lack full:

Knee extension

because the elevated fracture fragment creates a:

Mechanical block.

Physical Examination

The knee should be examined for:

Tenderness

Effusion

Range of motion

and

Stability.

Stability Testing

Gently assess:

Anterior

Posterior

Varus

and

Valgus stability.

In the acute setting, reliable testing may be difficult because of:

Pain

and

Guarding.

Anterior Laxity

Some patients demonstrate increased:

Anterior tibial translation

because the ACL remains attached to the:

Avulsed fragment.

Hemarthrosis

A tense hemarthrosis may significantly increase:

Pain

and limit the examination.

Imaging

Plain Radiographs

Standard:

AP

and

Lateral knee radiographs

are usually sufficient to identify the injury.

Importance of the Lateral View

The fracture is often best appreciated on the:

Lateral radiograph.

The degree of displacement seen on this view forms the basis of the:

Meyers and McKeever classification.

Small Fragments

The avulsed fragment may occasionally be:

Quite small

and can be subtle on:

Plain radiographs.

Additional Views

A:

Tunnel view

or an image oriented parallel to the slope of the:

Tibial plateau

may improve visualization.

MRI

MRI is useful for evaluating associated:

Meniscal

Ligamentous

and

Chondral injuries.

Adults

Adults with tibial spine fractures have a higher incidence of associated:

Meniscal tears

and other injuries that may require:

Operative treatment.

MRI is therefore particularly useful in:

Adult patients.

Pediatric MRI

MRI may also be helpful in children when there is concern for:

Meniscal entrapment

ACL injury

or unexplained failure of:

Closed reduction.

Pathological Findings

The fundamental injury is an:

Avulsion at the tibial attachment of the ACL.

ACL Footprint

The ACL has a broad tibial attachment and may blend with structures around the:

Anterior intercondylar region.

Meniscal Interposition

The:

Anterior horn of the medial meniscus

or other soft tissue may become trapped in the:

Fracture site.

This can prevent successful:

Reduction.

Differential Diagnosis

Important alternatives or associated injuries include:

Isolated ACL injury

PCL injury

MCL injury

LCL injury

Patellar fracture

Patellar tendon rupture

Tibial tubercle fracture

Tibial plateau fracture

and

Meniscal injury.

Treatment

Treatment depends primarily on:

Fracture displacement

Reducibility

Associated injuries

and

Skeletal maturity.

Initial Measures

Initial treatment includes:

Ice

Elevation

and

Immobilization.

Painful Hemarthrosis

If a large hemarthrosis is producing severe pain, aspiration may provide:

Symptomatic relief

and facilitate:

Examination.

Type I Fractures

Type I injuries are usually treated:

Nonoperatively.

Type II Fractures

Type II fractures may also be treated nonoperatively if they can be:

Completely reduced

and remain:

Stable.

Closed Reduction

Reduction is usually attempted by bringing the knee into:

Extension

or slight:

Hyperextension.

This can help restore the avulsed fragment toward its:

Anatomic position.

Immobilization Position

After successful closed reduction, the knee is generally immobilized near:

Full extension

typically around:

0–10° of flexion.

Immobilization Duration

Traditional immobilization is approximately:

6 weeks.

Modern treatment aims to balance fracture healing with avoidance of excessive:

Knee stiffness.

Type III Fractures

Type III fractures usually require:

Operative reduction and fixation.

Reason for Surgery

Surgery helps restore:

Articular anatomy

ACL tension

and

Knee stability.

Irreducible Type II Injury

A Type II fracture that cannot be reduced because of:

Soft-tissue interposition

should also be considered for:

Operative treatment.

Weight Bearing

Selected patients may be allowed:

Protected weight bearing

with the knee immobilized in:

Extension.

Exact weight-bearing status depends on:

Fracture stability

and

Treatment method.

Physical Therapy

Rehabilitation begins after adequate fracture:

Healing and stability.

Range of Motion

Therapy focuses on restoring:

Full knee extension

and progressive:

Flexion.

Strengthening

Progressive strengthening emphasizes the:

Quadriceps

and other muscles supporting:

Knee function.

Medication

Pain after injury may be treated with:

Acetaminophen

NSAIDs when appropriate

or other short-term:

Analgesics.

Surgery

Operative treatment is indicated for fractures that remain:

Displaced

or

Unreduced.

Arthroscopic Treatment

Arthroscopic reduction and fixation has become the preferred approach for many:

Displaced tibial spine fractures.

Advantages of Arthroscopy

Arthroscopy allows:

Direct visualization of the fracture

Removal of interposed tissue

and assessment of associated:

Meniscal or chondral injury.

Open Surgery

Open reduction remains an option when:

Arthroscopic reduction is not possible

or the fracture pattern requires:

Direct exposure.

Reduction

The fragment should be restored to its normal:

Anatomic position.

Any interposed:

Meniscus

Intermeniscal ligament

or other:

Soft tissue

must be removed from the fracture site.

Fixation

Fixation may be achieved using:

Screws

or

Heavy sutures.

Screw Fixation

Screw fixation can provide strong compression when the fragment is:

Large enough.

Suture Fixation

Suture fixation is particularly useful for:

Small

Comminuted

or

Cartilaginous fragments.

Physeal Considerations

In skeletally immature patients, implants should avoid crossing the:

Proximal tibial physis

whenever possible.

Near Skeletal Maturity

Crossing the physis may be acceptable in selected patients who are:

Close to skeletal maturity.

Postoperative Care

Postoperative management commonly includes a period of:

Protected motion

and

Bracing.

Early Motion

Because postoperative stiffness is an important complication, controlled:

Range-of-motion exercises

are generally begun once fixation permits.

Referral

Tibial spine fractures should be evaluated by an:

Orthopaedic surgeon.

Follow-Up

Patients should be followed closely to ensure:

Maintenance of reduction

and

Fracture healing.

Radiographic Follow-Up

Serial radiographs help assess:

Fragment position

and progression toward:

Union.

After Healing

Once the fracture has healed, the knee should be examined for residual:

ACL laxity

and

Functional instability.

Prognosis

When the fragment is anatomically reduced and securely fixed, functional results are generally:

Excellent.

ACL Stability

Most patients recover satisfactory:

ACL function

after successful healing.

Residual Laxity

Some patients retain measurable:

Anterior laxity

despite fracture union.

This may be asymptomatic.

Symptomatic Instability

Persistent symptomatic instability may eventually require:

ACL reconstruction.

Complications

Potential complications include:

Loose bodies

ACL laxity

Knee stiffness

Postoperative infection

and

Venous thromboembolism.

Knee Stiffness

Loss of motion is one of the most important complications, particularly when immobilization is:

Prolonged.

Arthrofibrosis

Severe postoperative stiffness may develop from:

Arthrofibrosis.

Prevention emphasizes:

Stable fixation

and appropriately timed:

Early motion.

ACL Laxity

Residual ACL laxity may result from:

Ligament stretching

Imperfect reduction

or altered:

Ligament tension.

Loose Body

A displaced osseous or osteochondral fragment may remain within the:

Joint

and become a:

Loose body.

Infection

Postoperative infection is uncommon but may involve:

Superficial tissues

or the:

Knee joint.

DVT

Venous thromboembolism is uncommon in children but remains a potential complication, particularly in:

Older or higher-risk patients.

Patient Monitoring

Monitoring should include assessment of:

Pain

Range of motion

Fracture alignment

Knee stability

and

Strength.

Key Principle

A tibial spine fracture is an avulsion fracture of the ACL attachment at the tibial intercondylar eminence, occurring most commonly in the:

Skeletally immature knee.

The classic:

Meyers and McKeever classification

describes Type I minimally displaced, Type II hinged, and Type III completely displaced fractures.

Plain:

AP and lateral knee radiographs

usually establish the diagnosis, while MRI is useful for identifying associated:

Meniscal and ligamentous injuries.

Nondisplaced or successfully reduced Type I and selected Type II injuries may be managed with:

Immobilization, whereas displaced, irreducible, or unstable fractures generally require:

Arthroscopic or open reduction and internal fixation.

The major long-term concerns are:

Knee stiffness, residual ACL laxity, and symptomatic instability.