L06 knee dislocations
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Transcript of L06 knee dislocations
Knee Dislocation
William R. Creevy, MS, MDAssistant Professor and Vice Chairman
Department of Orthopaedic SurgeryBoston University Medical Center
Mark A. Neault, MDBrian D. Busconi, MD
University of Massachusetts Medical School
Knee Dislocation
“It is unlikely that any single physician personally cares for more than a few
knee dislocations in a lifetime of practice”
JBJS 1971
Epidemiology
AUTHOR CENTER CASES REFERENCE
Frassica 1992 Mayo Clinic 14 2 million admissions
Wascher 1997 New Mexico 33 5 years
Eastlack 1997 US Army 28 5 years
Moore 1990 Denver 0.12 % of all trauma admissions
Epidemiology true incidence is probably underreported 20% - 50% spontaneously reduced practice environment
trauma center sports medicine practice general orthopaedics
Anatomy 4 ligament structures
ACL PCL MCL PLC
LCL popliteus biceps femoris ITB
Anatomy popliteal artery adductor hiatus soleus arch tension injury
hyperextension posterior
Anatomy peroneal nerve biceps femoris fibular neck tension
varus direct injury
Pathomechanics mechanism of injury
low energy - sports high energy - MVA position of knee direction of applied force degree of exagerrated motion
hyperextension varus/valgus anterior flexion + posterior force posterior
Pathomechanics Kennedy, 1963
10 cadaveric knee specimens hyperextension
ACL PCL posterior capsule @ 30º popliteal artery @ 50º
Pathomechanics avulsion injuries of cruciates
clinical studies: Sisto (1985) & Frassica (1992) combined data
80% PCL avulsion (“femoral peel off”) 30% ACL avulsion
Schenck (1999) cadaveric cruciate injury model hyperextension with variable strain (velocity)
high (5400%/sec): stripping lesion femur low (100%/sec): mid-substance tear
Classification purpose
determine prognosis (outcome) guide treatment
historical: Kennedy (1963) tibial position with respect to femur
visual inspection radiograhs
documented dislocation both cruciates torn
Positional Classification: Problems 20% - 50% reduced at presentation does not define exact status of ligaments
collateral: MCL vs. LCL-PLC knee dislocation with intact PCL
Myers (1975), Shelbourne (1992), Cooper (1992) ACL + collateral “simple treatment” vascular injury less likely?
knee dislocation with intact ACL Schenck (1992)
fracture dislocation patterns: Moore (1981)
Classification: Structures Involved
V
C
N
III L ACL / PCL / LCL+PLC MCL intact
IV ACL / PCL / MCL / LCL+PLC
III M ACL / PCL / MCL LCL+PLC intact
Schenck 1992
II
arterial injury
nerve injury
fracture dislocation
Anatomic Classification of Knee Dislocations
I single cruciate + collateralACL + collateralPCL + collateral
ACL / PCL collaterals intact
Anatomic Classification combined series application
Walker (1994): 13 patients Eastlack (1997): 28 patients
type III most common III L poor outcome vs. III M
duration of disability arthrofibrosis Sickness Impact Profile Lysholm and IKDC scales
Utility of Anatomic Classification
requires surgeon to focus on what is torn directs treatment to what is injured accurate discussion of injuries among
clinicians comparison of similar injuries within wide
spectrum of knee dislocations
Associated Injuries: Vascular high incidence combined results of 11 published series
average: 32% range: 8% to 64%
pathology intimal tear arterial disruption
direction of dislocation: no difference low velocity: decreased incidence?
Associated Injuries: Vascular Jones (1979)
“significant” arterial injury 4 of 15 (27%) patients “normal” post-reduction pulses liberal arteriography
Kendal (1993) surgical arterial injuries always present with change in vascularity: physical exam
pulse deficit diminished capillary refill
Lynch (1991) doppler pressure measurement ABI > 0.9 no clinically important vascular injuries selective arteriography
Physical Examination Inspection
± Obvious deformity Consider immediate reduction Hint: Coexistent varus/valgus instability in extension = ACL/PCL
injury ± Hemarthrosis
May be absent 2° to capsular disruption Popliteal ecchymosis Evaluate skin Hyperextension
Physical Examination Vascular Exam
Dorsalis pedis and posterior tibial arteries Pulse absent
Consider immediate closed reduction– If still absent O.R. for exploration– If pulse returns consider angiogram vs. observation
8 hour ischemic time is MAXIMUM Pulse present
A.B.I. > 0.9 observe A.B.I < 0.9 angiogram &/or exploration
Associated Injuries: Vascular DeBakey (1946)
WWII 80% amputation rate popliteal artery injury not revascularized
Green (1977) knee dislocation with popliteal artery injury 90% amputation if not revascularized within 8 hours
WHAT IS THE ROLE OF ANGIOGRAPHY?
Vascular Injuries: Principles1. Evaluate and document the vascular status (DP/PT
pulses and capillary refill) in any patient with a proven or suspected knee dislocation.
2. Once the dislocation is reduced the circulation should be re-evaluated.
3. Revascularization should be performed within 8 hours.
4. Arteriography should not delay surgical reanastomosis.
Vascular Injuries: Principles5. It is unacceptable to suggest spasm as a cause for
decreased or absent pulses in an attempt to justify observation.
6. If arterial insufficiency or abnormality is present, there is a vascular injury.
7. Arterial injury is treated with excision of the damaged segment and reanastomosis with reverse saphenous vein graft.
8. An experienced vascular surgeon should be utilized to verify clinical findings and interpret studies.
Vascular Injuries: Recommendations[A] ischemic limb after reduction
immediate surgical exploration injury and location predictable arteriogram: only if additional associated proximal injury
[B] abnormal vascular status - viable limb diminished pulses decreased capillary refill ABI < 0.9 “urgent” arteriogram
Vascular Injuries: Recommendations[C] normal vascular status and no ligament or
extremity surgery normal PT/DP pulses and normal capillary refill ABI > 0.90 careful observation with serial exams
vascular surgery and invasive radiology “available” MRA/MRI
evaluate for non-occlusive (intimal) injury sensitivity and specificity uncertain arteriogram if abnormal
Vascular Injuries: Recommendations[D] normal vascular status - potential or
planned ligament or extremity surgery normal PT/DP pulses and normal capillary refill ABI > 0.90 careful observation with serial exams
vascular surgery and invasive radiology “available” MRA/MRI as part of pre-operative evaluation routine arteriogram within 24 - 48 hours intimal injury
anticoagulation no tourniquet limited and delayed surgery (10-14 days) no endoscopic PCL (tibial tunnel)
Case Example: KD-IIIM
Physical Examination
Neurologic Exam Peroneal Nerve
EHL &/or tibialis anterior strength Dorsal 1st web space sensation
Tibial Nerve FHL &/or gastroc/soleus strength Lateral border & plantar surface of foot sensation
Associated Injuries: Peroneal Nerve incidence: 14% to 35% most common with Type III L (varus) traction injury disruption rare: nerve repair precluded usually axonotmesis
observation poor prognosis (<25% functional return) 12-18 months role of delayed decompression?
Associated Injuries: Peroneal Nerve nerve injury has an important influence on
surgical decision making absent peroneal never function impairs limb
function and activity level limited ligament surgery
LCL + PLC repair PCL avulsion
Physical Examination Isolated Ligament Exam
ACL Lachman @ 30°
PCL Posterior drawer @ 90°
LCL/PLC Varus stress @ 30° and full extension Tibial E.R. @ 30° Posterior tibial translation @ 30°
MCL Valgus stress @ 30°
Patellar tendon
Physical Examination
Combined Ligament Exam LCL/PLC & Cruciate
Varus in full extension & 30° MCL & Cruciate (PCL)
Valgus in full extension & 30° PLC & PCL
Tibial E.R. @ 30° & 90° Posterior tibial translation @ 30° & 90°
Stability in full extension Excludes significant PCL or capsular injury
Associated Injuries: Polytrauma knee dislocation is a spectrum of injuries
simple low energy sports related isolated injury
complex high energy vehicular trauma associated extremity and multi-system injuries
important differences future functional activities ability to participated in rehabilitation program other systemic and/or physiologic factors?
Associated Injuries: PolytraumaMills WJ : Severe HO After High Energy Knee Dislocation: The
Predicitve Value of the Injury Severity Score; OTA 2001.
35 consecutive knee dislocations Harborview Medical Center associated injuries
23% popliteal artery 20% peroneal nerve
surgical treatment 29: open acute [< 4 weeks] 6: arthroscopic delayed [6 wk - 10 m] CPM and early motion as wound permitted
Associated Injuries: PolytraumaMills WJ : Severe HO After High Energy Knee Dislocation: The
Predicitve Value of the Injury Severity Score; OTA 2001.
heterotopic HO: 6 patients (17%) ISS = 26-50 GCS = 3T-15
no heterotopic HO: 29 patients (83%) ISS = 9-26 GCS = 10-15 (2 severe brain injury)
6 of 23 (26%) multiple injuries developed HO positive predicitve value ISS > 26 = 86%
Associated Injuries: PolytraumaMills WJ : Severe HO After High Energy Knee Dislocation: The
Predicitve Value of the Injury Severity Score; OTA 2001.
HO occurred only in open acute cases (6/29 = 20%) 14% major wound complications bi-crucite surgery = 100% HO range of motion
4 ankylosis + 2 less than 10 º arc 3 open release and excision of HO - unsuccessful
6 delayed arthroscopic with ISS < 20: no HO range of motion
flexion average: 129º 50% flexion contracture >5 º 2 manipulation / 1 open release
Associated Injuries: PolytraumaMills WJ : Severe HO After High Energy Knee Dislocation: The Predicitve
Value of the Injury Severity Score; OTA 2001.
what is an ISS >26? ISS = sum 3 highest AIS² non-lethal single system injury of greatest magnitude: ISS = 25 two system injury needed to obtain ISS > 26
conclusion multisystem trauma and early open surgery increase risk for HO and loss of
motion poor functional outcome - not correctable change in treatment protocol at Harborview
limited early surgery brace or external fixation delayed surgery
Imaging the Dislocated Knee Plain X-ray
MRI
Arteriogram
Venography
CT Scan
Bone Scan
Plain Radiographs
Views AP & lateral 45° oblique Patellar sunrise
Findings Obvious dislocation Irregular/asymmetric joint
space Lateral capsular sign (Segond) Avulsions Osteochondral defects
MRI indications: all knee dislocations and equivalents
valuable diagnostic tool pre-operative planning
identify ligament avulsions: femoral PCL MCL: injury location incision lateral structures: popliteus, LCL, biceps meniscal pathology
displaced in notch early surgery limited arthroscopy 2º extravasation
articular cartilage lesions
Early Management ofKnee Dislocations
Orthopedic Emergency!!! Assess Neurovascular Status Closed Reduction
“Dimple sign” = irreducible (posterlateral dislocation) If No Pulse s/p Reduction
Vascular exploration Knee Immobilizer vs. External Fixation
Technique of Closed Reduction Anterior
Traction & elevation of distal femur Posterior
Traction & extension of proximal tibia Lateral / Medial
Traction & translation Rotational
Traction & Derotation AVOID force applied against popliteal fossa
Irreducible Knee Dislocation
Posterolateral “Dimple Sign”
Puckering of anteromedial skin Buttonhole
Medial femoral condyle thru medial retinaculum / capsule
Watch Skin Necrosis Open Reduction Required
Initial Stabilization ofKnee Dislocations
Knee Immobilizer Offers stability
External Fixation Better for grossly unstable knee Protects vascular repair Skin care for open injuries
NO Casting
Treatment: General Considerations most authors recommend repair of the torn
structures non-operative treatment: “poor results” period of immobilization
shorter = improved motion + residual laxity longer = improved stability + limited motion
recent clinical series have reported “better” results with operative treatment
no prospective, controlled, randomized trials of comparable injuries
Treatment: General Considerations immobilization after operative treatment
permanent stiffness flexion contracture (loss of extension) decreased flexion
early ROM is absolutely essential stable ligament fixation cooperative reliable patient
once stiffness occurs it is very difficult to treat
A loose mobile knee is better than a stable stiff knee!!
Treatment: Recommendations view the injury in the context of the whole
patient individualized treatment multiple variables 4 “key issues” that influence decision making
Treatment: RecommendationsKEY ISSUES
1. Associated injuries vascular injury nerve injury multi trauma head injury poor soft tissue envelope
LIMITED SURGICAL INTERVENTION
Treatment: RecommendationsKEY ISSUES
2. Presence of ligament avulsions “simplified” surgical treatment re-attachment
EARLY OPEN SURGERY
Treatment: RecommendationsKEY ISSUES
3. Complete posterolateral corner disruption is best treated with early open repair
LATE RECONSTRUCTION DIFFICULT
Treatment:RecommendationsKEY ISSUES
4. Reconstitution of the PCL is important allows tibiofemoral positioning around which collateral and ACL surgery evolve ACL reconstruction prior to PCL is never
indicated
PCL IS THE CENTRAL PIVOT
Non-operative Treatment immobilization in extension for 6 weeks external fixation
“unstable” or subluxation in brace obese multi-trauma head injury vascular repair fasciotomy or open wounds
Non-operative Treatment removal of fixator under anesthesia arthroscopy
manipulation for flexion assessment of residual laxity
Results of Ligament Reconstruction
Shapiro and Freedman 1995 10 Knee Dislocations Tx: 7 Patients
Early, Open Allograft Recon of ACL/PCL
MCL/LCL/PLC 1 repaired at time of OR
Average f/u 51 months Results:
6 patients good-excellent 4 of 7 needed manipulation
Fanelli et al 1996 20 Knee Dislocations Tx - Scope assist recon
ACL/PCL Allograft/autograft MCL tx non-op PLC tx w/biceps femoris Timing
PLC wait 2-3 weeks MCL 6 weeks rehab
Minimum f/u 2 years Results: knee scores, instability
Results of Ligament Reconstruction
Noyes & Barber-Westin 1997 11 Knee Dislocations Tx - Scope assist
Recon ACL/PCL Allograft/autograft Repair Medial/Lateral
Average f/u 4.8 years Immediate Motion Post-Op Results
5 required manipulation 9 patients full ROM 3 patients good-excellent
Wascher et al 1999 13 Knee Dislocations Tx
Allograft, Scope ACL/PCL recon Repair medial/lateral
Average f/u 38 months Results
Mean arc of motion 130 2 manipulations 1 knee “normal”, 6 sports
Results of Ligament Reconstruction
Yeh et al 1999 25 Knee Dislocations Tx - Scope
PCL recon / delay ACL 1 repair medial/lateral Timing 2 weeks
Average f/u 2 years Results
ROM 0 - 130 3 required scope debride 21 returned to office work
Cole and Harner 1999 25 Knee Dislocation Tx
Scope ACL/PCL recon 6 PLC recon / 7 MCL repair
Average f/u 3 years Results
5 lost 15 flexion 9 normal, 13 near normal KT-1000 = 0.1mm Timing w/in 3 wks preferred
Treatment of Specific Patterns
Treatment: KD-I
ACL + MCL MCL - predictable healing cylinder cast immobilization in extension for 2
weeks hinged brace ROM delayed ACL reconstruction
motion restored residual laxity and desired activity level
Treatment: KD-I
ACL + LCL/PLC delayed surgery @ 14
capsular healing identification of lateral structures
arthroscopic ACL - femoral fixation instruments and experience with open techniques femoral fixation tibial fixation / ACL tensioned after LCL/PLC
open posterolateral repair / reconstruction
Treatment: KD-II
ACL + PLC collateral ligaments intact
hinged brace + early ROM extension stop at 0º
arthroscopic reconstruction after 6 weeks PCL only in most cases ACL/PCL limited to high demand patient sedentary individuals = no surgery
Treatment:KD-IIIM
ACL + PLC + MCL immobilization in extension early surgery (2 weeks)
EUA and limited diagnostic arthroscopy (MRI) single straight medial parapatellar incision open PCL reconstruction or repair MCL repair
Case Example: KD-IIIM 47 year old female pedestrian MVA isolated injury examination
diffuse swelling and ecchymosis ROM: 10/0/80 normal DP/PT pulses motor sensory normal ligament testing
Lachman 3+post drawer 3+valgus 3+ 0º and 30ºvarus stable
Case Example: KD-IIIM closed reduction and brace arteriogram normal MRI
mid-substance ACL and PCL midsubstance MCL
EUA and stress radiographs
Case Example: KD-IIIM diagnostic arthroscopy
Case Example: KD-IIIM
Case Example: KD-IIIM
Case Example: KD-IIIM
Case Example: KD-IIIM
PCL Reconstruction: “Double Bundle”
Treatment: KD-IIIL ACL + PLC + LCL/PLC immobilization in extension delayed surgery @ 14 days
diagnostic arthroscopy arthroscopic or open PCL open LCL/PLC
incisions are critical - avoid midline PCL = medial (open or arthroscopic) straight posterolateral
42 female unrestrained front seat passenger MVA multiple injuries
laparotomy spleenectomy, hepatic packing LC-1 pelvis [R] knee dislocation
Case Example: KD-IIIL
knee examinationLachman 3+posterior drawer 3+valgus stablevarus 3+ @ 0º and 30 ºER all degrees
radiographs normal arteriogram normal immobilized in extension x 2 weeks
Case Example: KD-IIIL
Case Example: KD-IIIL
lateral exposure anatomic repair
ITB biceps femoris popliteus
tibial fibular
LCL posterior capsule meniscus
Case Example: KD-IIIL
Case Example: KD-IIIL
Case Example: PCL Femoral “Peel-Off”
Case Example: KD-IIILC 25 year old male motorcycle vs. telephone pole scene:
deformity knee confused and combative intubated and sedated
ground ambulance to local ER knee dislocation reduced abnormal vascular exam
Medflight to BMC
Case Example: KD-IIILC examination 3 hours after injury
effusion: none?swelling: severe, diffuse, ecchymosistenderness: sedatedROM: 15/0/120neurovascular: absent DP/PT pulses
cool pale footmotor / sensory NA
Case Example: KD-IIILC stability examination after injury
Lachman 3+posterior drawer 3+valgus stablevarus 3+ @ 0º and 30 ºER all degrees
isolated injury immediate treatment
4 compartment fasciotomy “on table” arteriogram in OR vascular reconstitution with RSV open lateral repair
Case Example: KD-IIILC
Case Example: KD-IIILC
Results of Ligament Reconstruction
Noyes & Barber-Westin 1997 11 Knee Dislocations Tx - Scope assist
Recon ACL/PCL Allograft/autograft Repair Medial/Lateral
Average f/u 4.8 years Immediate Motion Post-Op Results
5 required manipulation 9 patients full ROM 3 patients good-excellent
Wascher et al 1999 13 Knee Dislocations Tx
Allograft, Scope ACL/PCL recon Repair medial/lateral
Average f/u 38 months Results
Mean arc of motion 130 2 manipulations 1 knee “normal”, 6 sports
Results of Ligament Reconstruction
Yeh et al 1999 25 Knee Dislocations Tx - Scope
PCL recon / delay ACL 1 repair medial/lateral Timing 2 weeks
Average f/u 2 years Results
ROM 0 - 130 3 required scope debride 21 returned to office work
Cole and Harner 1999 25 Knee Dislocation Tx
Scope ACL/PCL recon 6 PLC recon / 7 MCL repair
Average f/u 3 years Results
5 lost 15 flexion 9 normal, 13 near normal KT-1000 = 0.1mm Timing w/in 3 wks preferred
Management of Nerve Injury
Exploration vs. Observation Early AFO Early Achilles Stretching Wait on Nerve Conduction Studies
At least 6 weeks, possibly 3 months Dynamic Bracing
i.e. articulating AFO Tendon Transfers PRN
Management of Nerve Injury
Surgical Exploration Intact BUT damaged
Observation 1 year or more until return 50% never return
Disruption Primary repair Cable grafting Results
– No good studies to date
Knee Dislocation: Summary anatomic classification selective use of angiography individualized surgical treatment
associated injuries limited surgery “corner repair”
multi-trauma head injury vascular or nerve injury
PCL + collateral
LOOSE AND MOBILE IS BETTER THAN STIFF AND STABLE
Return to Lower Extremity
Index