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
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