by: Nurul & Raden

KNEE ANATOMY

Bones• made up of four

main bones- femur, tibia, fibula & patella

• The main movements of the knee joint occur between the femur, patella & tibia.

Joints..- 3 joints within a single

synovial cavity :

1) Patellofemoral joint-Between patella & the patellar surface of femur-Planar joint (gliding)

2) Medial condylar joint3) Lateral condylar joint

- aka tibiofemoral joint- Between femur & tibia- Hinge joint (uniaxial)

Anatomical components of knee

Components

Capsule Ligaments

Extracapsular Intracapsular

Capsule• Surrounds sides & posterior

aspect of knee joint• On each side of patella, the

capsule is strengthen by tendons of vastus medialis & vastus lateralis

• Inside this capsule is synovial membrane which provides nourishment to all surrounding structures

Extracapsular Ligaments• Ligamentum patella

– Continuation of quadriceps femoris muscle

• Oblique popliteal ligament– Derived from semimembranosus

muscle

• Medial collateral ligament (MCL)

• Lateral collateral ligament (LCL)Posterior view

Intracapsular Ligaments

Intracapsular

Cruciate ligaments

Anterior

Posterior

MeniscusMedial

Lateral

Cruciate ligaments..

Anterior cruciate ligament (ACL)

Posterior cruciate ligament (PCL)

Origin Lateral femoral condyle Medial femoral condyleInsertion Anterior intercondylar of tibia Posterior intercondylar of tibiaAction • Prevent posterior

displacement of femur• Knee flex: Prevent anterior

displacement of tibia

• Prevent anterior displacement of femur

(Main stabilizer for femur in weight bearing esp during walking down hill)• Knee flex: Prevent posterior

displacement of tibia• Prevent hyperextension of knee

• Provide rotatory stability• Resist excessive valgus and varus angulation

Posterior view

PCL

Anterior view

ACL double bundles- Anteromedial (AM) bundle

prevent anterior displacement of tibia when knee flex

- Posterolateral (PL) bundle tightens when knee extend

PCL double bundles- Anterolateral (AL) bundle

prevent posterior displacement of tibia when knee near 90 flexion⁰

- Posteromedial (PM) bundle when knee extend

Meniscus

• Fibrocartilage disc interposed in between femoral condyles and tibial plateaus.

• Have a triangular cross section– thickest at the periphery– tapering to a thin central edge

Functions- Load transmission- Shock absorption- Joint stability & lubrication- Control rolling & gliding

actions of knee joint

Zones1. Red zone

Meniscus base; in immediate contact with joint capsule

2. Red-white zone Intermediate meniscus region

3. White zone White fringes

-Vessels penetrate through red zone until central third of the meniscus (red-white)

-The white fringe indicates no vessels- nourished via joint fluid

LATERAL MENISCUS

MEDIAL MENISCUS

Circular C-shaped

More mobile- More likely to move dt loose peripheral attachment

Less mobile- Less likely to move dt firm attachment to tibia and capsule via deep MCL

Less likely to tear

More likely to tear

Left knee

Blood Supply of the Knee• Femoral artery popliteal

artery help to form arterial network surrounding the knee joint.

• 6 main branches:-1. Descending genicular artery2. Superior medial genicular artery3. Inferior medial genicular artery4. Superior lateral genicular artery5. Inferior lateral genicular artery6. Anterior recurrent tibial artery

• The medial genicular arteries penetrate the knee joint.

Nerves of the Knee• Femoral nerve Saphenous nerve

• Sciatic nerve– Tibial nerve– Common peroneal

nerveSuperficial peroneal

nerveDeep peroneal nerve

Lateral view

Patella• Flat, triangular bone• In front of the knee joint• Sesamoid bone within tendon of

quadriceps femoris• Dense cancellous tissue, covered

by a thin compact lamina• Function :

– Protect the front of the joint– Increase leverage of Quadriceps

femoris by making it act at a greater angle

Base

Apex

Articular surface

• Anterior surface– Convex– Numerous rough and longitudinal striae– Covered by : an expansion from the

tendon of quadriceps femoris which it continous below with the superficial fibers of ligamentum patellae

– Separated from integument by a bursa• Posterior surface

– Smooth, oval, articular area– divided into two facets by a vertical

ridge : lateral and medial. the lateral facet is the broader and deeper.

– Below the articular surface is a rough, convex, non-articular area

• lower half : attachment to the ligamentum patellae

• upper half : separated from the head of the tibia by adipose tissue.

• Borders– Superior border (base) :

• thick, and sloped from behind, downward, and forward• attachment of the portion of the Quadriceps femoris which

is derived from the Rectus femoris and Vastus intermedius. – The medial and lateral borders

• are thinner and converge• attachment of those portions of the Quadriceps femoris

which are derived from the Vasti lateralis and medialis.

• Apex – Pointed– attachment of the ligamentum patellae

KNEE INJURIES

KNEE INJURIESPATELLA KNEE TIBIA

Dislocation of patella

Dislocation of knee Tibial plateau fractures

Fractured patella

Acute knee ligaments injuries (ACL, PCL,

MCL, LCL)Patella tendon

injuryMeniscal injury

PATELLA FRACTURE

Patellar fracture

I : Undisplaced crack fracture

II : Displaced transverse fracture

III : Comminuted (stellate) fracture

Mechanism of Injury• DIRECT FORCE (Fall onto knee / blow)

– Against dashboard of car : undisplaced crack or else a comminuted (‘stellate’) fracture without severe damage to the extensor expansions.

• INDIRECT FORCE (Traction force that pulls the bone apart and tears the extensor expansions)– Someone catches the foot against solid obstacle & to avoid

falling, contract the quadriceps muscle forcefully. transverse fracture with a gap between the fragments.

Clinical FeaturesKnee becomes swollen and painful. May be an abrasion or bruising over the front of the joint.

The patella is tender and sometimes a gap can be felt.

Active knee extension should be tested.

If there is an effusion, aspiration may reveal the presence of blood and fat droplets.

If the patient can lift the straight leg, the quadriceps mechanism is still intact.

If this maneuver is too painful, active extension can be tested with the patient lying on his side.

X-rayFracture with little or no displacement Severe comminutions

Treatment I. Undisplaced or minimally displaced fractures • Haemarthrosis should be aspirated. • The extensor mechanism is intact and

treatment is mainly protective.• A plaster cylinder holding the knee straight

for 3–4 weeks• Quadriceps exercises are to be practiced

every day.

II. Comminuted (stellate) fracture

• Patella undersurface is irregular serious risk of damage patellofemoral joint

• Patellectomy• Preserve the patella if the fragments are not

severely displaced by applying backslab.

III. Displaced transverse fracture

• The lateral expansions are torn and the entire extensor mechanism is disrupted.

• Operation is essential.• Patella repaired by the tension-band principle.• The fragments are reduced and transfixed with two stiff K-wires;

flexible wire is then looped tightly around the protruding K-wires and over the front of the patella.

• The tears in the extensor expansions are then repaired.• A plaster backslab or hinged brace (until active extension of the

knee is regained), removed every day to permit active knee-flexion exercises.

Transfixed by K-wires

Malleable wire is then looped around the protruding ends of the K-wires and tightened over the front of the patella.

PATELLA TENDON INJURY

• Mainly occur in patient younger than 40 years old- athlete or non-athlete

• Pain and tenderness in the middle of patellar ligament may occur in athletes- running and jumping sports

• Previous history of local injection of cortocosteroid

• History of: forceful contraction on a flexed knee (jump landing, weight lifting, stumbling)

• Complain of: sudden pain on forced extension of the knee

• Physical examination revealed hemarthrosis, proximally displaced patella, incomplete extensor function.

• Mechanism : – Sudden resisted extension of the knee

• Diagnosis by history, physical examination and radiological investigation.

Lateral X-ray of the knee

Normal lateral x-ray of knee with intact patella

Lateral x-ray of knee with rupture of patellar tendon - high riding patella

• MRI : help to distinguish a partial from a complete tear

Treatment • Partial tears

– Apply plaster cylinder

• Complete tears– Operative repair/

reattachment to the bone.

– Limits amount of flexion by using hinged brace for 6 weeks

PATELLA DISLOCATION

• Patella slips out of its normal position in the patellofemoral groove• Knee is normally angled in slight valgus natural tendency for the

patella to pull towards the lateral side when the quadriceps muscle contracts.

• Traumatic dislocation : severe contraction of the quadriceps muscle while the knee is stretched in valgus and external rotation

• Patella dislocates laterally and the medial retinacular fibres may be torn

• Clinical features– “First-time dislocation” : tearing sensation, feeling the knee has

gone out of joint– When running, collapse and fall to the ground– Swelling in the knee joint – Pain around the patella Impaired mobility in the knee – Obvious displacement of the knee cap lateral side of the knee

• The top of the patella attaches to the quadriceps muscle via the quadriceps tendon, the middle to the vastus medialis obliquus (VMO) and vastus lateralis muscles

• The bottom to the head of the tibia (tibial tuberosity) via the patellar tendon

• The medial patellofemoral ligament attaches horizontally in the inner knee to the adductor magnus tendon and is the structure most often damaged during a patellar dislocation.

• Finally, the lateral collateral and medial collateral ligaments stabilize the patella on either side.

Predisposing Factors• Young, female• Athletic Population

– Patellar dislocation occurs in sports that involve rotating the knee.– Direct trauma to the knee can knock the patella out of joint.

• Anatomical Factors– Insufficient VMO strength - The VMO functions in maintaining the patella in its desired

position within the patellofemoral groove during knee movements by pulling it towards the middle of the knee joint - an action known as 'tracking'.

– Q-angle - Larger than normal femoral angle (known as the Q-angle) and may have a 'knock-kneed' appearance (genu valgum). When the person straightens their leg, the patella will be forced to the outside of the knee. Thus any extra force applied to the inside of the knee may result in patellar dislocation.

– due to the central line of pull found in the quadriceps muscles that run from the anterior superior iliac spine to the center of the patella.

Male < 15 ̊

Female < 20 ̊> 25 ̊ high risk for patellar dislocation

Treatment • Conservative

– Pushed back patella into place. With knee straight, plaster backslab is applied for 3 weeks.

• Operative– When recurrent dislocations occur. To limit the amount of lost time in

competition and to reduce the chances for cartilage lesions on the undersurface of the patella, which often are non-reparable, patellar stabilization procedures are appropriate. These procedures can be either soft tissue or bone procedures, or a combination thereof. First-time traumatic patellar dislocations can also be treated with procedures such as this, and in chosen situations doing so may be appropriate.

– Surgically treating those dislocations by lessening lateral tension and tightening medial restraint could reduce this recurrence rate

Recurrent Dislocation• 15-20 % patient treated conservatively will

developed recurrent dislocation.• Predisposing factors :

– Generalized joint laxity– Marked genu valgum– Unduly high patella

DISLOCATION OF KNEE

Mechanism of injury• Femur-tibia joint disrupted • Cruciate ligaments & one/ both lateral ligaments are

torn

• Causes: Trauma – distinguish between high velocity injuries & low

velocity injuries (as this reflects incidence of vascular and nerve injuries);  low-velocity: occurrence of vascular injury is about 5%

and nerve injury is about 20%

Classification

Class

Anterior31%

Posterior25%

Lateral13%

Medial3%

Rotatory4%

1. Positional classification (Kennedy)-based on position of displaced proximal tibia

Anterior dislocation• > 30⁰ of hyperextension to produce this injury

– often PCL & ACL will both be torn– either MCL or LCL or both will be injured

Posterior dislocation• Anterior-to-posterior force on prox tibia (force

on flexed knee, dashboard injury)– possible extensor mechanism disruption

A PPA

AA PP

Lateral dislocation• Varus force

Medial dislocation• Valgus force

Rotatory dislocation• Rotatory force• Usually posterolateral

dislocation• + dimple sign• Often irreducible!

Medial

LL MM

Lateral

LL M M

Dimple sign

2. Anatomical classification (Schenck; modified by Wascher)- Based on ligamentous injury involvement

KD I Multiligamentous rupture with either cruciate intact

KD II Bicruciate rupture with both collaterals intact (rare)

KD IIIM Bicruciate and MCL ruptureKD IIIL Bicruciate and LCL ruptureKD IV Panligament ruptureKD V Knee dislocation with periarticular fractureC (+ to above) Arterial injury includedN (+ to above) Nerve injury included

Clinical features1. Severe bruising2. Gross deformity3. Swelling4. Pain5. Immobility6. Knee instability

Special test-to assess ligamentous injury

*Pulse (DPA, PTA)-exclude popliteal artery involvement*Distal sensation & dorsiflexion –exclude nerve injury

Examine!

Investigations1. X-ray (AP & lateral view)- Dislocation- may show periarticular #

- # of tibial spine (dt ligament avulsion)

2. Ankle-brachial pressure index (ABPI)..3. Duplex US4. CT angiography5. Arteriogram

6. MRI– assessment of which ligaments are intact– determine whether ligament tears are midsubstance or are avulsions

(off the femur or tibia)..

if doubt about circulation

ManagementFrom A&E to ward mx

1) Reduction under anaesthesia (URGENT!) No pulse reduce immediately Has good peripheral pulse pre-reduction x-ray

2) Rest limb on backslab with knee flex in 15⁰ To avoid re-dislocation

*No POP apply d/t swelling

3) If joint is unstable apply external fixator4) Apply ice & elevate knee (to reduce oedema)5) Post-reduction x-ray before assess for ligament injury6) Admit ward & check circulation during 48 hours

Operation if:

• Open wound• Vascular damage*Opportunity is taken to repair the ligaments and capsule; otherwise left undisturbed

7) Swelling subsided apply cast for 12 weeks8) Rehabilitation – quadriceps muscle exercises

Complications• Popliteal artery injury• Peroneal nerve injury• Open knee injury• Compartment syndrome

Acute

• Knee instability• Joint stiffness• Post-traumatic osteoarthritis

Chronic

ACUTE KNEE LIGAMENTS INJURY

Anterior Cruciate Ligament Injury

• One of the most common knee injuries is an ACL sprain or tear

• Common in sports such as soccer, basketball and rugby

• About half of all injuries to the ACL occur along with damage to other structures in the knee, such as articular cartilage, meniscus or other ligaments

Non-contact Traumatic force during twisting motion in weight-bearing

knee usually occurs when the athlete lands on the leg and quickly

pivots in the opposite direction (landing from jump)

ACL: Mechanism of Injury

Contact Blow to the lateral side of the extended knee esp at 0-30⁰

Usually a/w unhappy triad of injuries:1) MCL tear2) Meniscus tear3) ACL tear

Segond fracture - avulsion # of lateral aspect proximal tibial plateau

• PCL is approximately twice as strong and twice as thick as the normal ACL

• Therefore PCL is less commonly injured & an injury to PCL requires a powerful force

• Usually associated with ACL and collateral ligament injury (knee dislocation)

Posterior Cruciate Ligament Injury

PCL: Mechanism of InjuryDirect blow (anterior

force) onto the lower leg when knee flexed

e.g. a bent knee hitting a dashboard in a car accident or a football player falling on a knee that is bent

SymptomsACL injury PCL injury

Has ‘popping’ sound No ‘popping’ soundKnee swelling (haemathrosis) will occur between 2-12 hours of injury

Knee swelling (haemathrosis) within 3 hours of injury

May/ may not has immediate pain at knee joint

Pain at knee joint (common)

Instability sensation – knee giving way

Instability sensation – knee giving way

Discomfort when trying to put weight on injured leg

Difficulty walking

SignsExamine ACL injured PCL injured

LOOK Gross effusion (diffuse knee swelling)

Knee swelling (mild)Skin changes (contussion)Positive posterior tibial sag sign

FEEL Tenderness TendernessMOVE Limited ROM (lack of

complete extension)Usually full range of motion

SPECIAL TEST

+ve anterior drawer test (AM bundle tear)+ve Lachman test(PL bundle tear)

+ve posterior drawer test

Grading of injuriesGrading of ACL tear (based on physical examination)• Grade 1- 1-5 mm difference• Grade 2- 6-10 mm difference• Grade 3- 11-15 mm difference

Posterior sag sign• Grade I -side-to-side asymmetry exists but tibial plateau is

anterior to femoral condyles• Grade II -tibial plateau is even with femoral condyles• Grade III- tibial plateau falls behind the femoral condyles.

Investigationi. Plain x-ray of the knee

to look for avulsion fracture

ii. Stress x-rayshow whether the hinges open on one side (instability)

iii. MRI (90-98% sensitivity for ACL tear)differentiate partial & complete tears

iv. Arthroscopy for reconstruction of cruciate ligament tears

Medial Collateral Ligament Injury

Function of MCL• resists widening of

inside of the knee joint

• prevents the knee joint from medial instability (prevents valgus angulation of knee)

MCL: Mechanism of Injury• results of direct blow to lateral side of knee

– This pushes the knee inwards (toward the other knee)• excessive valgus force applied to a partially flexed

knee – E.g. when a rugby player gets clipped on the outside of

the leg, this opens the angle between the femur and tibia, stretching the MCL & leads to tear or complete rupture.

• May be an isolated injury, or it may be part of a complex injury to the knee.

Lateral Collateral Ligament Injury

Function of LCL• prevents the knee joint from lateral instability

(prevents varus angulation of knee)

LCL: Mechanism of Injury• results of direct blow to medial side of knee..• occurs in sports that require a lot of quick stops &

turns (e.g. soccer, basketball, skiing) or ones where there are violent collisions (e.g. football or hockey)

• greater force is required to rupture LCL than MCL• often accompanied by other injuries;

– common peroneal nerve injury: it is near LCL- can be stretched during the injury or is pressed by swelling in the surrounding tissues

– rupture of the biceps femoris (hamstring) tendon

SymptomsMCL LCL

SYMPTOMS •Pain ranging from mild to severe (depending on how serious the injury)

-Pain that can be mild or acute-Numbness or weakness in the foot if involve peroneal nerve

-Stiffness-knee may give way under stress or may lock

SIGNS •Swelling

•Tenderness along inside of knee

•Positive valgus stress test

•Swelling

•Tenderness along outside of knee

•Positive varus stress test

InvestigationMCL LCL

Plain knee x-ray-Calcified deposit seen on medial site of knee (Pellegrini-Steida syndrome)

Plain knee x-ray- Fibular head avulsion #

Stress knee x-ray-Complete tear of medial ligament

Stress knee x-ray-Complete tear of lateral ligament

MRI MRI

RICE methodUsed for acute soft tissue (sport) injury

• Rest: vital to protect the injured muscle, tendon, ligament or other tissue from further injury and to promote effective healing.

• Ice: Cold provides short-term pain relief & limits swelling by reducing blood flow to the injured area. (apply cold compresses for 15 min and then leave them off for the skin to re-warm)

• Compression: helps limit & reduce swelling. Some people also experience pain relief from it.

• Elevation: help to control swelling. It's most effective when the injured area is raised above the level of the heart. (if injury to ankle, pt lying on bed with foot propped on one or two pillows)

Management of Acute Ligament Injury

Sprains and partial tearsi. RICE method

- Weight bearing is allowed with knee is protected from rotation or angulation strains by a heavily padded bandage or functional brace

ii. +/- aspirate haemarthrosis, NSAID

iii. Active exercise - to prevent adhesion during spontaneous healing (intact

fibres splint the torn ones)

Physiotherapy – early ROM & strengthening of

muscle that stabilizes knee jt

Complete tears• Isolated tears of PCL/ MCL/ LCL treated as above• Isolated tears of ACL may be treated by early operative

reconstruction if patient is professional sportsman

Avulsion # of tibial intercondylar eminence• Reducible fragment & can fully extend knee

immobilize in plaster cylinder for 6 weeks• Irreducible or block to full extension open reduction

& fixation (strong sutures/ small screws if physis has closed) + immobilize in plaster cylinder for 6 weeks

Combined injuries(ACL + collateral ligs OR PCL + collateral ligs)

• Joint bracing & physiotherapy – to restore good ROM

• If involve ACL ACL reconstruction• If involve PCL PCL reconstruction

+ repair all damage structures

MENISCAL INJURY

Mechanism of Injury• Meniscus been split in its length by a force

grinding in between femur and tibia• In young adults, usually due to rotational

grinding force Weight is taken on flexed knee & there’s twisting strain e.g. footballers flex and twist the knee + direct contact (tackle)

leading to tear

• Middle-aged/ elderly often caused by stiffening and menisci fibrosis that has restricted mobility of the meniscus tear (even with little force)

• Medial meniscus is commonly affected than lateral meniscus.– Medial meniscus attached to the capsule.– This make it less mobile compared to lateral

meniscus, thus it cannot easily accommodate to normal stresses.

TYPES OF

TEAR

Longitudinal or vertical (bucket-handle)

Flap or oblique

Radial or transverse

Horizontal

Complex degenerati

on

most common

OA-changes associated

Confined to centre; usually degenerative or due to repetitive minor trauma & some a/w meniscal cyst

Bucket-handle tear• Split is vertical and runs along part of the

circumference of the meniscus create loose slivers which is still attached anteriorly and posteriorly. posterior

anterior

Longitudinal/ vertical tear

Bucket-handle tear

Handle displaced into intercondylar fossa (centre of the knee

joint) jammed btwn femur-tibia block to

extension (locked knee)

•A longitudinal tear is a vertical tear in the meniscus with a longitudinal direction, usually located in the periphery of the meniscus.

•The longer the tear, the more unstable it is; leading to dislocation of the central part of the meniscus bucket‐handle tear.

Flap/ radial/ horizontal tears

* A flap tear may also be caused by a horizontal tear

A flap tear is an oblique vertical cleavage producing a flap (parrot beak)

A radial tear is a vertical tear starting from inner free margin toward periphery

SymptomsYoung person • twisting injury to knee on the

sports field• Pain severe & further activity is

avoided• Swelling (appears some hours

later/ the next day)• Knee is locked in partial flexion• With rest, initial symptoms

subside, only to recur periodically after trivial twists or strains

• Sometimes knee gives way spontaneously & again followed by pain & swelling

‘locking’ -sudden inability to extend the knee fully but able to fully flex the knee – suggest a bucket-handle tear-Patient sometimes learn to unlock the knee by bending fully or twisting it from side to side

Patient > 40 yo• initial injury maybe

unremarkable• chief complaint mainly

recurrent ‘giving way’ or ‘locking’

Signs• Joint held in flexed position• Joint effusion• Quadriceps muscle wasting (late presentations)• Tenderness around joint line• Flexion is full but extension is often slightly

limited• Positive McMurray’s or Apley’s Grinding

Test..

Investigation• X ray (usually normal)• Arthroscopy

– Advantage in identifying & treating lesion at the same time

• MRI– Most reliable to confirm dx

• Absent bow-tie sign– May reveals tear that is missed by arthroscopy

ManagementConservative management

If knee is not lock tear maybe at peripheral may heal spontaneously

– Joint held straight in backslab for 3 to 4 weeks– Physiotherapy– Analgesics– Activity modification

Operative management– Surgery indicated if:a) the joint cannot be unlockedb) symptoms are recurrent

– Tear close to periphery sutured (have capacity to heal)

– Tear other than peripheral third excise the torn portion

FRACTURE OF TIBIAL PLATEAU

• Tibial plateau is the top of the tibia that makes up part of the knee joint

• There are two bulges at the end of the tibia called lateral and medial condyles

Anatomy of tibial plateau

Causes of tibial plateau #Strong bending force combined with axial loadse.g. a car striking on a pedestrian (from knee side) aka bumper

fracture; fall from a height in which the knee is forced into valgus or varus

One or both tibial condyles are crushed or split by opposing femoral condyle

Most commonly affect lateral tibial plateau due to:valgus alignment of lower extremitymost injuring forces are directed laterally to medially

Clinical features Joint swollen & has doughy feel of

heamarthrosis Diffuse tenderness on side of fracture site Diffuse tenderness on opposite site (if

associated with ligament injury) Restricted movement or unable to bear weight

InvestigationX-ray : multiple views to show true extent of the #

Schatzker V tibial plateau fracture

Schatzker’s classification

• based on fracture pattern and fragment

anatomy

TreatmentPrinciple: function is more important than pretty x-ray

Traction alone often produces a well-functioning knee

Undisplaced & minimally displaced lateral condyle #• Aspirate haemarthrosis• Apply compression bandage• Knee movements as soon as pain & swelling subsided

– Hinge cast-brace* weight-bearing is not allowed for another 3 weeks

Marked displaced &/or comminuted lateral condyle #• Open reduction and internal fixation (lag screw & buttress plate)• Elevate depressed area• Bone grafting – to support the reduction

Medial condyle #• ORIF• Repair associated lateral ligament damage

Bicondylar #• ORIF (combination of screw fixation and circular external

fixation offers satisfactory stabilization)

Osteoporotic condylar fractures• As above, sometimes need total knee replacement

ComplicationEarly Late

• Compartment syndrome-esp type 5 & 6: tendency to bleed and swelling

examine leg and foot repeatedly for sx of compartment syndrome

•Joint stiffness-failure to regain full knee bendminimised by early movement

Deformity-residual valgus or varus deformity is quite common-compatible with good function

•Secondary osteoarthritis-caused by plateau depression, knee deformity or ligamentous instability

Thank you for your attention…