The Dislocated Knee

Muhammad Syafiq Fitri(C 111 07 308)

Advisorsdr. Salman

dr. Rico Alexander

Supervidor:dr. Henry Yulianto, Sp OT

Orthopaedic and Traumatology DepartmentHasanuddin University

2012

Journal of the American Academy of Orthopedic SurgeonsJ Am Acad Orthop Surg 1995;3:284-292

Abstract

Rare, result of high- or low- velocity injuryUrgent diagnosis & treatment, avoid vascular

complication and amputation.Initial evaluation include objective assessment of

arterial circulation.Operative approach for young and healthy patient

is outlined.Absence definitive clinical studies, timing and

extent of the repair/reconstruction, optimum rehabilitation still remain uncertain.

Individual patient management must be dictated by circumstances such as instability, swelling, activity level, and the risk of postoperative joint stiffness.

Introduction

Rare, diagnose was confined obviously at the scene of an accident or when arrived at hospital.

Vascular and nerve Injury frequently associated.

Still uncommon, but probably rising due to increase vehicle, sport activity, better recognition of the entity.

Anatomy Joint stability and normal knee kinematics

are maintain by the shape of the femoral and tibial condyles with 4 major ligamentAnterior cruciate ligament (ACL)Posterior cruciate ligament (PCL)Medial collateral ligament (MCL)Lateral collateral ligament (LCL)

Dynamic stabilizers – muscle acting over and inserting in proximity to the joint.

Popliteal fossa, separated from posterior joint capsule by a layer fat, run the popliteal artery and vein.

Artery tethered proximally by the adductor hiatus and distally by soleus arch, bifurcates into anterior and posterior tibial arteries.

Genicular arteries the popliteal fossa collateral circulation around the joint.

collateral circulation is insufficient to maintain popliteal artery is transected or obstructed

Tibial and common fibular nerves run superficial to the constraining adductor hiatus, tibial nerve run deep to soleus arch, less vulnerable to injury

Classification

Base on :1. the direction of displacement;2. whether the dislocation is confirmed

complete or presumed complete;3. whether the injury is open or closed; 4. whether the injury was caused by high-

energy trauma or low-energy trauma.

Mechanism of Injury

Anterior dislocation by hyperextending knee specimens, establishing that the dislocation was preceeded by rupture of the posterior capsule and cricuate ligament.

Posterior dislocation, posteriorly directed blow to the proximal tibia.

Medial and lateral dislocation result of extreme forces, varus or valgus rotatory moments of lower leg, high energy accident.

Posterolateral, involve flexed knee, non-weight-bearing situation and a sudden rotatory moment.

Associated Injuries

Ligament InjuryACL not always torn completelyCollateral ligament only stretched in

anterior and posterior dislocationsPCL was torn with anterior and

posterior dislocation.Purpose ligament considered

disrupted one grade III or IV (International Knee Documentation Committee definition)

Vascular InjuryStreching of popliteal artery (anterior

dislocation)Direct contusion of the vessel by the

posterior rim of the tibial plateau (posterior dislocation)

Total vessel rupture, anterior and posterior dislocation

Nerve injuries Involve common peroneal nerve Usually associated with lateral, medial and

rotatory dislocation

FracturesAssociated with multiple traumaTibial plateau fracture and small avulsed or

sheared-off bone fragments from proximal tibia or distal femur are commonly seen.

Pure knee dislocationJoint instability, soft tissue and neurovascular

complication.soft tissue repair

Plateau FractureComminuted tibial plateau fracture with

capsular or ligamentous disruptionbone fixation

Evaluation and Early ManagementGeneral ConsiderationRadiologic examination without mal-alignment

or swelling, absent with rotatory dislocations.The presence of a dimple sign posterolateral

dislocationVascular injury sensory and motor dysfunction

repeat examination for several days

Reduction Reduced immediately Intravenous administration of adjuvant drug Tractionproximal tibialdepending on

dislocation Reevaluation after reduction

Vascular InjuryImpaired circulation is absence

of palpable pedalpulses.Cyanosis or pallor, weak

capillary refill.decreased peripheral

temperature.Doppler pressure measurement

& arteriographic findings.Preoperative

arteriorgraphyfacilitate vascular reconstruction

most common method vascular repair resection of the damaged portion of the artery followed vein grafting.

Absolute Surgical Indication.Arterial injury, state of irreducibility, open

dislocation and compartment syndrome indication immediately.

Definitive Treatment of Ligament Injuries

Delay of surgery (except absolute acute surgical indication)

to allow a period of vascular monitoringreduce the risk of postoperative

arthrofibrosisACL injuries is that surgery should be

delayed until swelling has resolved and full range of motion has been regained

immobilization of the knee jointplaster casts combination with transfixing pin.

Surgical Approachevaluation and definitive treatment of

associated vascular lesionsArthroscopyContraindicatedan acute dislocation,

risk of compartment syndromefluid leaking out of the ruptured capsule.

great help when performing delayed surgery.

accomplished in most cases within 2 to 3 weeks after the injury.

Limb swelling must be monitored

Definitive Treatment for Nerve Injury

Nerve disruption, often have ill-defined edges, which must be resected and which require nerve grafting, since neural circulation is very sensitive to even a small increase of tension.

Functional disability often persists after injuries to the peroneal nerve.

Restoring active function by a later tendon transfer

Management RecommendationShould always be suspected in cases of

multiple traumaKnee reduction should be performed in the

emergency room if possibleClose collaboration with the radiologist and

the vascular surgeon in the acute phase is vital.

In cases of complete occlusion or disruption, vascular repair must be done within 8 (preferably 6) hours.

Fasciotomy should be performed if a compartment syndrome threatens.

If acute surgery must be undertaken, ligaments should be repaired or reconstructed during the same session unless contraindicated.

All patients who have sustained knee dislocation must be closely monitored for late vascular compromise during the first week after injury.

Knee-motion exercises should be started early if the integrity of the ligaments and the vascular repair permits.

Summaryserious injury with a high rate of associated

neurovascular injury.rare occurrencedefinitive treatment are

based on assumptions and short term observations.

multiple ligament disruptions result of low-velocity injuries vascular complications.

Thank You