Traumatic Knee Traumatic Knee DislocationsDislocations

IntroductionIntroduction

• Rare injuryRare injury

• Incidence might be higher, but goes Incidence might be higher, but goes unrecognised probably because unrecognised probably because dislocation would have reduced at the dislocation would have reduced at the scene of injury itself.scene of injury itself.

• True orthopaedic emergency- extensive True orthopaedic emergency- extensive ligamentous damage and potential for ligamentous damage and potential for vascular complications associated with vascular complications associated with these injuries.these injuries.

Basic stabilisers of kneeBasic stabilisers of knee

• Medial collateral ligament, Medial collateral ligament, semimembranosus, tendons of pes semimembranosus, tendons of pes anserinus, and oblique popliteal anserinus, and oblique popliteal ligament – medial stabilisersligament – medial stabilisers

• ITB, LCL, popliteal tendon, biceps ITB, LCL, popliteal tendon, biceps femoris – lateral stabilisers.femoris – lateral stabilisers.

• Crutiates – anterior and posterior and Crutiates – anterior and posterior and rotatory stabilisers.rotatory stabilisers.

Mechanism of injury Mechanism of injury

• High energy trauma: motor vehicle High energy trauma: motor vehicle accidentsaccidents

• Pedestrian versus motor vehicle Pedestrian versus motor vehicle accidents.accidents.

• Athletic events like football injuryAthletic events like football injury• Low energy injury is less frequent but Low energy injury is less frequent but

do occur: in obese patients – fall while do occur: in obese patients – fall while getting downstairs – these are getting downstairs – these are challenging to treat.challenging to treat.

Mechanism of injuryMechanism of injury

• Exaggerated hyperextension of knee – Exaggerated hyperextension of knee – produce knee dislocation.produce knee dislocation.

• ACL tore first – followed by PCL – followed ACL tore first – followed by PCL – followed by posterior capsule at 30* of by posterior capsule at 30* of hyperextension – popliteal artery tear at hyperextension – popliteal artery tear at 50* of hyperextension.50* of hyperextension.

• A varus/ valgus force combined with A varus/ valgus force combined with hyperextension causes variable degree of hyperextension causes variable degree of collateral ligament injury too.collateral ligament injury too.

Associated injuriesAssociated injuries

• VascularVascular

• Neurological injuryNeurological injury

• Osteochondral fracturesOsteochondral fractures

• Menisci injuriesMenisci injuries

Vascular injuryVascular injury

• Vascular structures are securely Vascular structures are securely fixed proximally at the adductor fixed proximally at the adductor hiatus and distally at the soleus arch hiatus and distally at the soleus arch – hence exaggerated tibiofemoral – hence exaggerated tibiofemoral displacement causes vascular displacement causes vascular rupture.rupture.

• Incidence – 7 – 15%Incidence – 7 – 15%

• Surgical emergency Surgical emergency

Neurological injuryNeurological injury

• Peroneal nerve – commonest nerve Peroneal nerve – commonest nerve to get injuredto get injured

• Incidence: 14 to 35%Incidence: 14 to 35%

• Poor prognosisPoor prognosis

• Tibial nerve if injured – even less Tibial nerve if injured – even less favourable prognosis.favourable prognosis.

ClassificationsClassificationskennedy classificationkennedy classification

• Based on displacement of tibia over Based on displacement of tibia over femurfemur

• AnteriorAnterior

• PosteriorPosterior

• Medial Medial

• LateralLateral

• Rotatory: anteromedial/anterolateral/ Rotatory: anteromedial/anterolateral/ posteromedial/ posterolateral.posteromedial/ posterolateral.

PositionPosition Characteristics Characteristics

Anterior Anterior Most common type, Most common type,

Arterial injury [traction]Arterial injury [traction]

Hyperextension – most Hyperextension – most common causecommon cause

PosteriorPosterior Arterial injury – [complete Arterial injury – [complete tear]tear]

High association with extensor High association with extensor mech rupturemech rupture

Posterolateral Posterolateral IrreducibleIrreducible

MFC buttonholes through MFC buttonholes through medial capsulemedial capsule

High incidence of peroneal High incidence of peroneal nerve palsynerve palsy

Transverse skin furrow Transverse skin furrow mediallymedially

Adv / dis adv of position Adv / dis adv of position classification classification

Adv:Adv:

• Guides the surgeon the reduction maneuverGuides the surgeon the reduction maneuver

• Alerts the associated complications.Alerts the associated complications.

Dis adv:Dis adv:

• Due to spontaneous reduction difficult to Due to spontaneous reduction difficult to classifyclassify

• Doesn’t specify the anatomic structures that Doesn’t specify the anatomic structures that are torn which in turn guides the surgical are torn which in turn guides the surgical decision making.decision making.

Anatomic classification by Anatomic classification by schenckschenck

• Based on clinical examination and MRIBased on clinical examination and MRI

• Based on the anatomic sturctures that are Based on the anatomic sturctures that are torntorn

• Assigns numbers based on which ligaments Assigns numbers based on which ligaments are torn.are torn.

• Higher the number higher is the level of Higher the number higher is the level of injury.injury.

• System considers four ligament groups: System considers four ligament groups: ACL, PCL, PMC and PLC.ACL, PCL, PMC and PLC.

ClassificationClassification Injury patternInjury pattern

KD1KD1 Knee dislocation with Knee dislocation with one crutiate lig intactone crutiate lig intact

KD2KD2 Bicrutiate knee Bicrutiate knee dislocationdislocation

KD3MKD3M Bicrutiate lig tear, + Bicrutiate lig tear, + PMC torn. PLC intactPMC torn. PLC intact

KD3LKD3L -do- but PMC intact-do- but PMC intact

KD4KD4 Bicrutiate and both Bicrutiate and both corners torncorners torn

KD5KD5 Fracture dislocationFracture dislocation

• KD3 – most common patternKD3 – most common pattern

• KD3L prognosis bad compared to KD3L prognosis bad compared to KD3M w.r.t arthrofibrosis, instability, KD3M w.r.t arthrofibrosis, instability, and disability.and disability.

• KD4 – high energy injury – associated KD4 – high energy injury – associated with arterial injury.with arterial injury.

Clinical featuresClinical features

• History : of high enery trauma, dash board injury.History : of high enery trauma, dash board injury.• painpain• On/e: irreducible knee dislocationOn/e: irreducible knee dislocation• Knee swelling [ if extensive capsular tear, swelling Knee swelling [ if extensive capsular tear, swelling

might not be prominent]might not be prominent]• Occasionally subtle signs like abrasions, minimal Occasionally subtle signs like abrasions, minimal

swelling.swelling.• Examination under GA – shows gross ligamentous Examination under GA – shows gross ligamentous

laxity.laxity.• Associated fractures : femur shaft, acetabulum, and Associated fractures : femur shaft, acetabulum, and

tibial plateau #s.tibial plateau #s.• Note: Acurate diagnosis in a polytrauma case Note: Acurate diagnosis in a polytrauma case

requires high index of suspicion.requires high index of suspicion.

Clinical assessmentClinical assessment

• Look for distal pedal pulses at Look for distal pedal pulses at admission, after 4-6 hours, and at 24 admission, after 4-6 hours, and at 24 hours following admission.hours following admission.

• Colour and temp of distal limb.Colour and temp of distal limb.

Investigations Investigations

• Plain X ray of knee: Plain X ray of knee:

Possible findings include-Possible findings include-

Avulsion fragmentsAvulsion fragments

Asymmetry between lateral and Asymmetry between lateral and medial joint spacesmedial joint spaces

MRIMRI

• Helpful to assess the structures that Helpful to assess the structures that are torn when clinical evaluation is are torn when clinical evaluation is difficult due to associated fractures.difficult due to associated fractures.

• Also helpful in assessing the Also helpful in assessing the ligamentous damage in a ligamentous damage in a spontaneously reduced knee.spontaneously reduced knee.

• Note: MRI to be done before the Note: MRI to be done before the stabilisation of fractures to avoid stabilisation of fractures to avoid metal artifacts.metal artifacts.

Vascular assessment.Vascular assessment.

• Routine arteriography not necessary Routine arteriography not necessary for all cases.for all cases.

• Only those injuries where in a Only those injuries where in a vascular insult is suspected during vascular insult is suspected during clinical assessment can be subjected clinical assessment can be subjected to arteriography.to arteriography.

• Also, doppler USG can be an easy Also, doppler USG can be an easy initial screening inv to rule out a initial screening inv to rule out a vascular injury.vascular injury.

Treatment optionsTreatment options

Rx

Operative Non Operative

Non Operative options Non Operative options

Indications:Indications:• Critically ill Patient unable to tolerate the Critically ill Patient unable to tolerate the

surgical proceduresurgical procedure• Grossly contaminated woundGrossly contaminated wound• In very elderly sedentary person.In very elderly sedentary person.Available options:Available options:• Long leg or cylinder castLong leg or cylinder cast• Long leg knee brace locked in extension if Long leg knee brace locked in extension if

wound care is needed repeatedly.wound care is needed repeatedly.

• 7 -8 weeks of immobilisation7 -8 weeks of immobilisation

• Followed by removal of castFollowed by removal of cast

• Manipulation under GAManipulation under GA

• Later rehabilitation primarily for Later rehabilitation primarily for achieving maximum knee motionachieving maximum knee motion

Operative TreatmentOperative Treatment

• Involves repair of all injured ligaments.Involves repair of all injured ligaments.• Can be open repair or arthroscopic.Can be open repair or arthroscopic.• Open injury – open repair is prefferedOpen injury – open repair is preffered• Bony avulsions of ligaments are generally Bony avulsions of ligaments are generally

treated best by open repair and soon after treated best by open repair and soon after injury.injury.

• General preference is arthroscopic repair General preference is arthroscopic repair of acl/pcl and open repair of posterolateral of acl/pcl and open repair of posterolateral and posteromedial complex.and posteromedial complex.

Timing of surgeryTiming of surgery

Very little data exists in literature Very little data exists in literature regarding ideal timing for surgery.regarding ideal timing for surgery.

Usually has to be individualized based Usually has to be individualized based on:on:

• Open or closed injuryOpen or closed injury

• Degree of contamination if openDegree of contamination if open

• Degree of associated soft tissue injury Degree of associated soft tissue injury if closed.if closed.

Timing of SurgeryTiming of Surgery

• Acute repair = repair done within 3 Acute repair = repair done within 3 weeksweeks

• Chronic repair = repair done > 4 weeks.Chronic repair = repair done > 4 weeks.Adv of delayed repair: Adv of delayed repair: • Better nutritional state after recovering Better nutritional state after recovering

from traumafrom trauma• Improved local soft tissue conditionImproved local soft tissue condition• Thus a potentially decreased risk of Thus a potentially decreased risk of

infection and wound dehisence.infection and wound dehisence.

Adv of Acute repair:Adv of Acute repair:

• Decreased total trauma recovery Decreased total trauma recovery timetime

• Improved healing of the injury to the Improved healing of the injury to the capsule of knee by taking advantage capsule of knee by taking advantage of the inflammatory reaction of the inflammatory reaction associated with the initial injury.associated with the initial injury.

Reconstruction vs non Reconstruction vs non operative Rxoperative Rx

• Studies show that surgically treated Studies show that surgically treated patients had better motion, stability, patients had better motion, stability, and return to work and recreational and return to work and recreational activities.activities.

Lateral/ posterolateral Lateral/ posterolateral reconstructionreconstruction

• If no significant laxity can be treated If no significant laxity can be treated conservatively.conservatively.

• If laxity present surgery is the main If laxity present surgery is the main stay of Rx.stay of Rx.

• Repair of all injured ligaments, Repair of all injured ligaments, posterolateral capsular posterolateral capsular advancement, and augmentation of advancement, and augmentation of posterolateral structures.posterolateral structures.

Posterolateral Posterolateral reconstructionreconstruction• Local rotation of a strip of iliotibial band on Local rotation of a strip of iliotibial band on

a distally based pedicle - to reconstruct a distally based pedicle - to reconstruct the popliteus.- by mullerthe popliteus.- by muller

• Central slip of biceps tendon – to augment Central slip of biceps tendon – to augment popliteofibular ligament by muller.popliteofibular ligament by muller.

• Achilles tendon / BPTB reconstruction – Achilles tendon / BPTB reconstruction – noyes technique.noyes technique.

• Reconstruction with semitendinosus by Reconstruction with semitendinosus by larsen.larsen.

Posterolateral instability with Posterolateral instability with varus knee varus knee

• Pre op – evaluate any varus alignment of Pre op – evaluate any varus alignment of knee. knee.

• Soft tissue reconstruction alone will not be Soft tissue reconstruction alone will not be sufficient in such knee as varus thrust will sufficient in such knee as varus thrust will stretch out the reconstructed lateral stretch out the reconstructed lateral complex.complex.

• Hence high tibial valgus osteotomy will have Hence high tibial valgus osteotomy will have to be done before or during posterolateral to be done before or during posterolateral reconstruction of a varus knee.reconstruction of a varus knee.

Posteromedial Posteromedial reconstructionreconstruction

• Partial MCL tear heal well with non Partial MCL tear heal well with non operative Rxoperative Rx

• In type 1 and 3 injuries mcl In type 1 and 3 injuries mcl reconstruction is performedreconstruction is performed

• Chronic mcl laxity needs repair.Chronic mcl laxity needs repair.

• Involvement of posterior oblique Involvement of posterior oblique ligament needs repair.ligament needs repair.

Posteromedial Posteromedial reconstructionreconstruction

• Tibialis anterior and tibialis posterior Tibialis anterior and tibialis posterior allografts have been used for PMC allografts have been used for PMC reconstruction.reconstruction.

• MCL reconstruction done by routing a MCL reconstruction done by routing a soft tissue graft between the soft tissue graft between the attachment points of superficial MCL attachment points of superficial MCL

• Later capsular reefing.Later capsular reefing.

• Arthroscopic ACL and PCL Arthroscopic ACL and PCL reconstruction has to be done.reconstruction has to be done.

• Choice of the grafts depends on the Choice of the grafts depends on the structures injured.structures injured.

• BPTB graft , hamstrings for ACL.BPTB graft , hamstrings for ACL.

• Achilles tendon for PCL Achilles tendon for PCL reconstruction.reconstruction.

Post op rehabilitationPost op rehabilitation

• Knee in full extension x 6 weeksKnee in full extension x 6 weeks

• NWBCA x 6 weeksNWBCA x 6 weeks

• Protected Knee range of motion can Protected Knee range of motion can be started at 3be started at 3rdrd week. week.

• Brace is discontinued after 10Brace is discontinued after 10thth week. week.

• Return to sports after 9Return to sports after 9thth post op post op month.month.

Order of reconstructionOrder of reconstruction

• PCL is reconstructed firstPCL is reconstructed first

• Followed by ACLFollowed by ACL

• Followed by posterolateral complexFollowed by posterolateral complex

• And posteromedial complex.And posteromedial complex.

Order of reconstruction and Order of reconstruction and tensioning of grafttensioning of graft

• After PCL fixation tension the pcl with After PCL fixation tension the pcl with knee in 90 * of flexionknee in 90 * of flexion

• Later ACL fixation and tensioning of Later ACL fixation and tensioning of ACL done in full extension of kneeACL done in full extension of knee

• Repair, augment and reconstruct the Repair, augment and reconstruct the collaterals.collaterals.

• Last – radiographic confirmation of Last – radiographic confirmation of knee joint reduction.knee joint reduction.

Complications Complications

Due to deficiencies in evaluation: Due to deficiencies in evaluation: • Faliure to recognise vascular injuryFaliure to recognise vascular injury• Associated ligamentous injuryAssociated ligamentous injury• Lower extremity mal-alignment Lower extremity mal-alignment Due to surgical intervention:Due to surgical intervention:• Vascular injuryVascular injury• Nerve injuryNerve injury• Compartment syndromeCompartment syndrome• Wound healing problemsWound healing problems• Physeal injuriesPhyseal injuries• fracturesfractures

Long term complicationsLong term complications

• Chronic instabilityChronic instability

• ArthrofibrosisArthrofibrosis

• Post traumatic arthritisPost traumatic arthritis

• Articular cartilage injuryArticular cartilage injury

• Chronic pain in the knee due to any Chronic pain in the knee due to any of the above problems.of the above problems.

Sai RamSai Ram