Updated PCL, PLC and Knee Dislocation for Postgraduate Orthopaedic Course in Newcastle March 2015

PCL and PLC

Professor Deiary KaderConsultant Orthopaedic & Trauma Surgeon

Knee SurgeonNewcastle Nuffield Hospital

PostGrad Orth Deiary Kader

Postgraduate Orthopaedics FRCS(Tr&Orth) Revision Course

Newcastle Upon Tyne 16-21 March 2015

•


Knee Surgeon

Nuffield Hospital Newcastle

NGMV Charity

Classification of knee Stabilizers

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Lateral ComplexIT TractLCLPopliteusBiceps Femoris

Central ComplexACLPCLMed MenxLat Menx

Medial ComplexMCLPostromedial CapsuleSemi-MembPes anserinus

PCLThree components:

AL Bundle: Long and thick part, 2X the size of PMB

Tightens in flexion

PM Bundle: Tight in extension

Meniscofemoral ligaments: mechanically very strong

Anterior: Humphrey’s ligament

Posterior: Wrisberg’s ligament

Ant Meniscofemoral lig of Humphrey


a. Ant Meniscofemoral lig

Humphrey

b. Post Meniscofemoral lig

Wrisberg



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9PostGrad Orth Deiary Kader

PCL

✦ The strongest ligament in the knee

✦ It is “a central stabilizer”

✦ Originates from a broad crescent-shaped area MFC

✦ Inserts centrally posteriorly 1–1.5cm below articular

surface of the tibia

✦ Average length of 38 mm and diameter of 13 mm

✦ PCL and quadriceps are dynamic partners in

stabilizing the knee in the sagittal plane

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PCLMechanism of Injury

RTA– High Velocity– Often MLI

Sports

Uncommon – Low Velocity– Usually Partial

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Mechanism of injury

3% of all knee injuries

Dashboard Injury at 90° is the most common

Falling on a flexed knee with foot in plantar flexion

Forced hyperextension (>30º) is associated with

multi-ligament injury

High association with fracture femur

Presentation

Acute isolated PCL injury is commonly missed

Present with very little pain in the knee without hemarthrosis

There may be only bruising at the popliteal fossa.

Chronic PCL injury on the other hand may present with pain in

the medial compartment or anterior knee pain.

In isolation, it often causes little long-term

instability. However, it may lead to medial or PFJ

pain (OA) at a later date.

More troublesome in soccer players due to

difficulty in deceleration.

Presentation 2

Diagnosis 2Clinical

Posterior drawer test at 90° and 30°

Quadriceps active drawer test. Flexion 60°

Posterior sag sign (step-off)

Posterolateral rotatory instability (Dial test prone)

External rotation recurvatum test

Diagnosis 1

MRI & PCL

Clinical examination is more reliable than MRI scan

The PCL may be dysfunctional despite normal MRI

Kneeling stress x-ray

Measure the degree of translation


Grading of PCL instability

Normal tibia step-off is 10 mm at 90° flexion

Instability could be mild, moderate or severe

Grade I instability is when there is a 5-mm step-off

Grade II instability is when there is no step-off (flush)

Grade III instability is when there is –5 mm step-off

There is a high association between Grade III PCL

injury and posterolateral corner injury.

Treatment

Treat acute, isolated PCL injury conservatively

Extension brace with calf support

(Posterior Tibial Support, PTS Brace) until the

pain subsides (4-6 weeks) with quadriceps

rehabilitation

Start early passive motion only in prone position to

maintain anterior tibia translation.

Surgical reconstruction

Indications

• Acute combined injuries

• Acute bony avulsion

• Symptomatic chronic PCL injuries that failed

rehabilitation.

• There is no difference in clinical outcome between

single and double bundle PCL reconstruction.

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PCL Reconstruction


Complications

Immediate

Neurovascular injury popliteal vessels

Infection

Technical error → tunnel placement, graft tensioning, insecure

fixation

Delayed

Loss of motion

Avascular necrosis (medial femoral condyle)

Recurrent or persistent laxity (common) when a combined injury is

not adequately addressed


What are the structures in the Posterolateral Complex of the

Knee?

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Posterolateral Complex

Components:

– Biceps, ITB, Popliteus, Popliteofibular

ligament, arcuate ligament, LCL

Function

– Resists External and Varus rotation

Mechanism of Injury

– Direct blow to anteromedial tibia

– Hyperextension/varus


The Posterolateral Corner (PLC)

Primary stabilisers of external tibial

rotation at all knee flexion angles

Secondary restraints to anterior and

posterior translation

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The Posterolateral CornerResist Ext Rotation of Tibia

The LCL is a cord like structure 5-7 cm in lengthS

Primary static restraint to varus opening of the knee

Secondary restraint to posterolateral rotation

The popliteus is a static and dynamic external rotation stabiliser.

The popletiofibular ligament acts as

a primary restraint to external rotation of

the tibia on the femur at 30º of flexion 25

The Posterolateral Corner (PLC)

Isolated PLC sectioning produce a maximal

Average increase of 13° of tibial ER at 30° of knee flexion

Average increase of 5.3° of tibial ER at 90°

Isolated PCL sectioning has no effect on external tibial rotation

Combined injury to the PCL and PLC leads to ER of 20.9° at

90° of knee flexion26

Posterolateral Complex Injury

Physical Examination

– Dial Test

• Increased External rotation (30o, 90o)

– Posterolateral external rotation test

– External rotation recurvatum


LCL Examination

Opening @ 30º only

– Isolated LCL Injury

Opening @ 0º

– Injury to Posterolateral Capsule (+ Dial)

– Usually with ACL +/or PCL injury

Palpate LCL in Figure 4 Position

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Fib

Pop

Extension

The popliteus tendon inserted 10 mm distal 5 mm posterior to the lateral epicondyle

The LCL inserted 2 mm proximal 4 mm posterior to the lateral epicondyle


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Common Peroneal Nerve

FEMURFibula head


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Popliteofibular LIG


Posterolateral ComplexImaging

Plain Films

Check for Biceps/LCL Avulsion fracture

MRI

Can be helpful

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Posterolateral ComplexInjury--Treatment

Partial

– Grade I & II Instability with a good end point

– Nonsurgical Treatment

– 1-3 week immobilisation in extension

Complete Acute

– Primary repair best

– Augment with allo/auto graft

Complete Chronic

– Reconstruct Popliteus and LCL 34

PLC Reconstruction The reconstruction can be:-

✴Fibula based such as modified Larson’s technique or

✴Combined tibia and fibula based such as LaPrade’s

anatomical reconstruction.

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THANK YOU

The principles of surgery

Early repair/ Recon (within 3 weeks) of torn and detached ligaments,

tendons and capsule in acute injuries. A combination of early repair and

reconstruction has been shown to provide better results.

Late reconstruction of the two or three of the main stabilisers of the

posterolateral corner of the knee i.e. the lateral collateral ligament,

Popliteus tendon, and popliteofibular ligament in chronic cases.

Combined ACL/PCL and PLC injury must be treated by reconstruction of all injured

ligaments. Isolated ACL or PCL reconstruction without addressing the PLC will

ultimately fail.37

Knee dislocation

Any triple-ligament knee injury constitutes a frank

dislocation. This is relatively rare but a severe and

potentially limb-threatening injury.

High-energy injury such as RTA

Sporting accident

May be missed on initial assessment.

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Vascular Injuries

Previously it was thought there was a 50%

incidence of vascular compromise Now 3.3-18%

20%–30% incidence of nerve injury.

Fracture incidence may be as high as 60%.

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Classification Classified on the basis on tibial displacement in respect to the femur

Closed or open

High or low energy

Dislocation or subluxation

Neurovascular involvement

Anterior (common: 30-50% of dislocations, associated with intimal tears)

Posterior; also medial, lateral (highest rate of peroneal nerve injury) and

rotatory (usually irreducible) or combined

Hyperextension leads to anterior dislocation

Dashboard injury leads to posterior dislocation

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ExaminationValgus and varus laxity

Anteroposterior translation

Recurvatum

>10º hyperextension suggests ACL injury

>30º hyperextension indicates PCL injury

Rotation indicates MCL and LCL injury


Management

Surgical emergency

Deal with life-threatening injuries first

Circulation in A&E

Serial examination for 48 hours.

Ankle brachial Index (ABI)

ABI <0.9 is suggestive of significant arterial injury

Involve the vascular surgeon

Radiography before manipulation

– (assess direction and associated fracture)

Reduction as soon as possible in the emergency/operating Room

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Management

Immobilization in an extension knee splint

Check radiograph to confirm congruity, if not, consider

external fixator

Conservative management out of favour

Early surgical reconstruction and/or repair, is currently

recommended by the Knee Dislocation Study Group

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ManagementSurgery as soon as the vascular surgeon allows

Most ACL/PCL/MCL can be treated with bracing the MCL followed by

combined ACL/PCL reconstruction once range of movement is restarted,

usually after 6 weeks.

ACL/PCL/posterolateral corner can be treated by repairing the

posterolateral corner acutely (within three weeks) and delayed ACL/PCL

reconstruction 8 weeks later. Or all in One

Open dislocation, fracture dislocation and vascular compromise require

staged procedures.

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THANK YOU

Postgraduate Orthopaedics FRCS(Tr&Orth) Revision Course

Newcastle Upon Tyne 16-21 March 2015

•


Knee Surgeon

Nuffield Hospital Newcastle

NGMV Charity

Health & Medicine

Updated PCL, PLC and Knee Dislocation for Postgraduate Orthopaedic Course in Newcastle March 2015