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485 Cards in this Set
- Front
- Back
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Iliotibial tract/band |
tightness can cause lateral knee and/or thigh pain |
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Quadriceps muscle |
atrophy can indicate and/or contribute to knee pain |
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Quadriceps tendon |
can rupture w/ eccentric loading - defect is palpated here |
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Patella |
- tenderness can indicate fx - swelling can be prepatellar bursitis |
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Patellar tendon |
- can rupture w/ eccentric loading - defect is palpated here |
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Patellar retinaculum |
- patellar femoral ligament palpated here - they can be injured in patellar dislocation - Plicae can also be palpated here |
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Joint line |
tenderness here can indicated meniscal pathology |
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Tibial tubercle |
Tender in Osgood-Schlatter disease |
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Pes anserinus and bursa |
- insertial of medial hamstrings - bursitis can develop - site of hamstring tendon harvest |
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Gerdy's tubercle |
insertion of iliotibial tract/band |
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Popliteal fossa |
popliteal artery pulse can be palpated here |
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Muscle compartments |
will be firm or tense in compartment syndrome - anterior most common |
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Distal femur characteristics |
2 condyles of distal femur - medial - larger and more posterior - lateral - more anterior and proximal |
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Trochlear groove |
depression between condyles anteriorly for patellar articulation |
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Intercondylar notch |
between condyles, site of cruciate origins |
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Distal femur ossification |
Distal physis ossifies at birth and fuses at 19 years |
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Femoral condyles |
- rounded posteriorly (for flexion) and flat anteriorly (for standing) - Epicondyle: origin of collateral ligaments - Epicondylar axis and/or post condylar axis used to determine femur rotation |
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Sulcus terminale |
groove in lateral condyle - inferior to groove - it is weight bearing portion of condyle |
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Adductor tubercle |
insertion of adductor magnus |
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Distal femoral physis |
grows approximately 7mm/year |
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Patella characteristics |
- Ovoid shaped, inferior/superior poles - Triangular in cross section - 2 facets (larger anterior/medial) separated by a central ridge - each facet is subdivided into superior, middle, inferior facets - Odd facet (7th sub facet) is far medial on medial facet - odd facet articulates in deep flexion - has thickest articular cartilage |
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Patellar ossification |
- ossifies at 3 years and fuses at 11-13 years |
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Largest sesamoid bone in body |
patella |
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Bipartite patella |
failure of superolateral portion to fuse - often confused with fracture |
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patella function |
- enhances quadricep pull (fulcrum) - enhances knee lubrication |
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contact point on patella moves |
proximally w/ flexion |
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Tibia: proximal end plateau |
- medial plateau: concave - lateral plateau: convex - 7-10 degree posterior slope |
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Tibial tubercle |
3 cm below joint line |
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Tibial eminence |
medial and lateral tubercles |
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Tibial shaft |
triangular cross section |
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Distal end of tibia |
Pilon (cancellous bone) - articular surface: plafond - Distal tip: medial malleolus |
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Tibial shaft ossification |
ossifies at 7 weeks fetal and fuses at 18 years |
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Secondary ossification of tibia |
- proximal epiphysis ossifies at 9 mos and fuses at 18-20 yo - Distal epiphysis/tibial tuberosity ossify at 1 year and fus at 18-20 yrs |
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___________ tibial plateau fx more common |
lateral |
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Osgood schlatter |
traction apophysis at open tibial tubercle apophysis |
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Tibial tubercle |
patellar tendon insertion |
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IM nail insertion point _________ to patellar tendon |
proximal |
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Tibial spine avulsion fx |
ACL (peds) |
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Gerdy's tubercle |
proximal tibia - insertion site of IT band |
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Fibularis incisa |
lateral groove for fibula |
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Planford |
roof and medial malleolus is medial wall of ankle mortise |
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Fibula characteristics |
- long bone characteristics - Proximal end: head and neck - shaft: long, cylindrical - distal end: lateral malleolus |
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Primary ossification of fibula |
Shaft ossifies at 7 weeks fetal and fuses at 20 years |
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Secondary ossification of fibula |
- proximal epiphysis ossifies at 1-3 years and fuses at 18-22 years - Distal epiphysis ossifies at 4 years and fuses at 18-22 years |
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Fibula comments |
- LCL and biceps femoris insert on head - Neck has groove for peroneal nerve - Nerve can be injured in fibula fx - Shaft used for vascularized BG - Latearl malleolus is lateral wall of ankle mortise |
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Anatomic axis of femur |
line drawn along the axis of femur |
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anatomic axis of tibia |
line drawn along the axis of tibia |
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mechanical axis of femur |
line drawn between center of femoral head and intracondylar notch |
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mechanical axis of tibia |
line drawn between center of knee and center of ankle mortise |
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knee axis |
line drawn along inferior aspect of both femoral condyles |
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Vertical LE axis |
vertical line, perpendicular to the ground |
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Lateral distal femoral angle |
- angle formed between axis and femoral axis laterally |
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Medial tibial angle |
angle formed between knee axis and tibial axis |
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Knee axis relationship |
parallel to the ground and perpendicular to vertical axis |
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Mechanical axis of femur relationship |
average of 6 degrees from anatomic axis - approx 3 degrees from vertical axis |
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Mechanical axis of tibia relationship |
- normally same as anatomic axis of tibia unless tibia has a deformity |
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Lateral distal femoral angle |
- 81 degrees from femoral anatomic axis - 87 degrees from femoral mechanical axis |
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Medial proximal tibial angle |
87 degree from tibial mechanical axis |
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AP knee XR technique |
supine, beam at 90 degrees |
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AP knee XR findings |
- medial/lateral compartments - varus/valgus deformity |
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AP knee XR clinical application |
- femoral condyle - tibial plateau/spin - patella fx - OCD - OA |
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Lateral knee XR tech |
supine, 30 degree flexion |
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Lateral knee XR findings |
patellofemoral compartment - fractures - quadriceps/patellar tendon rupture |
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Axial/sunrise knee XR tech |
- prone - knee 115 degrees flexion - beam at patella 15 degrees cephalad |
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Axial/sunrise knee findings |
- Patellofemoral compartment - patellofemoral arthritis - malalignment of patellar tilt |
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Tunnel/notch knee XR tech |
- prone - knee 45 degree flexion - beam is caudal at knee joint |
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Tunnel/notch knee XR findings |
- posterior femoral condyles, intercondylar notch, tibial eminence - Osteochondral fx/defect - femoral condyle or tibial eminence fx - DJD/OA |
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Merchant knee XR tech |
- supine - legs of table at 45 degrees - beam at PF joint |
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Merchant knee XR findings |
- Patellofemoral compartment (patellar articular facets) - Articular surface lesions - DJD - tilt or malalignment |
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Rosenberg knee XR tech |
- PA weightbearing - knees at 45 degrees |
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Rosenberg knee XR findings |
- Medial/lateral compartments - OA of WB protion of posterior condyles |
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AP tibia XR tech |
- supine - beam at mid tibia |
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AP tibia XR findings |
- tibia and surrounding soft tissues - fractures, deformity, infection etc |
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Lateral tibia XR tech |
- supine - beam laterally mid tibia |
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Lateral tibia XR tech |
- tibia and surrounding soft tissues - fractures, deformity, infection |
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Alignment films technique |
Bilateral full length hip to ankle, WB |
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Alignment films findings |
- full lower extremity alignment - determine malalignment/deformity |
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Scanogram technique |
entire b/l LE w/ ruler |
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Scanogram finding |
- measure length of bones
- used for leg length discrepancy |
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Patellar fx |
- mechanism: direct and indirect (dashboard) - Pull of quad and tendons displace most fxs - If intact, retinaculum resists displacement of fragments - Do not confuse w/ bipartite patella (unfused superolateral corner) |
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Patellar fx H&P |
- hx: trauma, pain, cannot extend knee, swelling - PE: Dome effusion, tenderness, +/- palpable defect, inability to extend knee |
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Patellar fx workup |
- XR: knee trauma series - CT: not usually needed, will show fx fragments |
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Patellar fracture classification |
- non displaced - transverse - vertical - stellate - inferior/superior pole - comminuted |
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Patellar fx tx - non displaced/comminuted
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knee brace/cast 6-8 weeks - ROM - severely comminuted may require full or partial patellectomy |
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Patellar fx tx - displaced |
- > 2-3 mm - ORIF (tension bands) to restore articular surface |
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Patellar fx complications |
- OA and/or pain - decreased motion and/or strength - AVN - refracture |
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Knee dislocation |
- Rare: ortho emergency - Usually high energy - Multiple ligaments and other soft tissues are disrupted - high incidence of associated fx/neurovascular - many spontaneously reduce, must keep index of suspicion for injury - Close follow up is important for good result |
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knee dislocation H&P |
- Hx: trauma, pain, inability to bear weight - PE: large effusion, soft tissue swelling, deformity, pain, +/- distal pulses, peroneal nerve dysfunction |
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knee dislocation workup |
- XR: AP/lateral - AGRAM: evaluate for arterial injury - MR: ligament injury, meniscus, articular cartilage injury |
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knee dislocation classification: by position |
- anterior - posterior - lateral - medial - rotatory: anteromedial/anterolateral |
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knee dislocation tx |
- early reduction essential, postreduction neurologic exan and XR - immobilize 6-8 weeks (if lig. not torn) - surgery if irreducible or vascular injury (revascularize within 6 hrs + fasciotomy) - Early vs delayed ligament repair/reconstruction |
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knee dislocation complications |
- neurovascular - popliteal artery - peroneal nerve injury - knee stiffness - chronic instability |
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Tibial plateua fractures |
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tibial plateau fx |
- mechanism: axial load AND varus/valgus stress - restoration of articular surface/congruity is important - Metaphyseal injury: bone will compress, leading to functional bone loss, may need bone graft - Lateral fx more common than medial - associated meniscal and ligament (MCL>ACL) tears |
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Tibial plateau fx H&P |
- hx: trauma, pain, swelling, inability to bear weight - PE: effusion, tenderness, do thorough neurovascular exam |
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tibial plateua fx work up |
- XR: knee trauma series - CT: to better define fx lines and communition. Needed for pre-op planning - AGRAM: if decreased pulses. Consider in all type IV fxs |
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Tibial plateau fx classification |
Schatzker - I : lateral plateau split fx - II : lateral split/depression fx - III : Lateral plateau depression - IV: Medial plateau, split fx - V : Bicondylar plateau fx - VI : fx w/ metaphyseal diaphyseal separation - Types IV-VI usually result from high energy trauma |
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Tibial plateau fx tx |
- consider joint aspiration - nondisplaced ( <3mm step off, < 5mm gap) - knee brace/cast 6-8 weeks, NWB 6-12 weeks - Displaced: ORIF +/- bone grafts (plates and screws) Early ROM but NWB 12 weeks - Avoid both medial and lateral periosteal stripping (incr non union rate) - repair torn ligaments/enisci |
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Tibial plateau fx complications |
- compartment syndrome - post traumatic arthritis - persistent knee pain - popliteal artery injury |
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Tibial shaft fx |
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Tibial shaft fx |
- common long bone fx - usually high energy trauma - condition of surrounding soft tissues is critically important to success of outcome - compartment syndrome: consider in ALL fxs - subcutaenous position of tibia predisposes it to open fxs - may lead to amputation |
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Tibial shaft fx H&P |
- hx: trauma, pain, swelling, inability to bear weight - PE: swelling , deformity +/- firm/tense compartments |
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Tibial shaft fx work up |
- XR: AP and lateral of tib/fib (knee and ankle series) - CT: not usually needed - AGRAM: if decreased pulses |
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Tibial shaft fx classification |
- location - displaced/comminuted - Type: transverse, spiral, oblique - Rotation/angulation |
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Tibial shaft fx tx |
- non-displaced: long leg cast 8 weeks (best for pediatrics, seldom in adults) - displaced/unstable: reamed, locked IM nail - Open fractures: thorough I&D is critical. External fixation is useful for these fxs - Fasciotomies for compartment syndrome |
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Tibial shaft fx complications |
- compartment syndrome - non union and malunion - knee pain from IM nail - ankle and/or knee stiffness |
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Compartment syndrome |
- Incr pressure in closed space/compartment - compartments have rigid fibroosseous borders - mechanism: trauma, vascular injury, burn |
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Compartment syndrome H&P |
- Hx: trauma, pain - PE 5 P's: pain w/ passive stretch, paresthesia, pulseless, paralysis, pulseless - firm/tense compartments |
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Compartment syndrome work up |
- XR: eval for fx - AGRAM: if needed to evaluate for vascular injury - Compartment pressures: - Absolute > 30-40 degree - Change in pressure: < 30 mmHg of diastolic blood pressure |
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Maisonneuve and Pilon fx |
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Maisonneuve fx |
- complete syndesmosis disruption w/ diastasis and proximal fibula fx - variant of ankle fx and deltoid ligament rupture - unstable fx |
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Maisonneuve fx work up |
- Hx: trauma, ankle pain, +/- knee pain - PE: ankle pain, swelling, proximal fibula tenderness - XR: leg and ankle series. May need stress views of ankle to see instability |
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Maisonneuve fx classification |
Descriptive by location: - location - type: spiral, oblique, comminuted |
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Maisonneuve fx tx |
- Reduce and stabilize syndesmosis - immobilize while healing |
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Maisonneuve fx complications |
- ankle instability/ arthritis |
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Pilon (Distal tibia) fx |
- intraarticular: through distal articular/WB surface - Soft tissue swelling leads to complications w/ early open tx - restoration of articular surface congruity is essential - healing is often slow |
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Pilon (distal tibia) fx work up |
- Hx: trauma, cannot bear weight, pain, swelling - PE: effusion, tenderness, do good neurovascular exam - XR: AP/lateral obliques - CT: needed to better define fx and pre op plan |
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Pilon (distal tibia) fx classification: Ruedi/Allgower |
- I : non or minimally displaced - II : displaced: articular surface incongruous - III : comminuted articular surface |
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Pilon (distal tibia) fx tx |
- nondisplaced: cast and NWB for 6-12 weeks - displaced/comminuted: early external fixation and delayed (14 days) ORIF (plates and screws +/- grafting) |
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Pilon (distal tibia) fx |
- post traumatic - DJD - stiffness - malunion - wound complications |
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Knee structure |
Comprises 3 separate articulation - medial and lateral femorotibial joints - condyloid hinge joints - femoral condyles articulate w/ corresponding tibial plateaus - Patellofemoral joint - sellar (gliding) joint. Patella articulates w/ femoral trochlea groove |
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Knee compartments |
- medial - lateral - patello/femoral |
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Knee capsule |
- surrounds entire joint - all three articulations/compartments - extends proximally into the suprapatellar notch - Capsule has a synovial lining that covers the cruciate ligaments (intraarticular but extrasnyovial) |
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Articular hyaline cartilage |
- type II collagen - covers the femoral condyles, tibial plateaus, trochlear groove |
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knee menisci |
- interposed in medial and lateral femorotibial joints - protect the articular cartilage - give support to the knee |
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Knee axis |
- line drawn between weight bearing portion of medial/lateral femoral condyles is parallel to the ground - Mechanical axis of the femur is 3 degrees valgus to the vertical axis, allowing the larger MFC to align with LFC parallel to the ground - mechanical axis of the tibia is 3 degrees varus to the vertical axis (87 degrees to knee axis) |
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Knee kinematics (1) |
- inherently unstable joint - bony morphology adds little stability - stability provided by surrounding static/dynamic stasbilizers |
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Medial stabilizers |
- static: superficial and deep MCL, posterior oblique ligament - dynamic: semimembranosus, vastus medialis, medial gastrocnemius, PES tendons |
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Lateral knee stabilizers |
- static: LCL, ITB, arcuate ligament - dynamic: popliteus, biceps femoris, lateral gastrocnemius |
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knee ROM |
Knee has 6 degrees of motion - F/E - ER/IR - varus/valgus - ant/post translation - med/lateral translation - compression/distraction |
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Flexion and extension are main motion of knee |
- flexion is a combo of rolling and sliding of the femur on the tibia in varying ratios depending on degree of flexion - cruciate ligaments control the roll/glide function. PCL alone can maintain this fxn - F/E (-5 to 140 degrees) - 115 degrees needed to get out of a chair - 130 degrees needed for fast running |
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Rolling |
equal translation of tibiofemoral contact point and joint axis - rolling predominates in early flexion |
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Gliding |
translation of tibiofemoral contact point without moving the joint axis - increased gliding is needed for deep flexion |
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IR/ER of knee |
- about 10 degrees total through arch of motion. Tbia IR's in swing, and ERs in stance via screw home mechanism - Screw home mechanism: larger MFC ERs tibia in full extension, tightening cruciates and stabilizing the kne in stance - Popliteus IRs the tibia to unlock the knee, loosen the cruciates, which allows the knee to initiate flexion |
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Anterior/posterior knee translation |
- dependent on tissue laxity - usually within 2 mm of contralateral side in normal knees |
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Varus/valgus in knee |
- approximately 5mm of gapping laterally or medially when stressed in normal knees |
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ACL (anteromedial/posterolateral bundle) |
- Posteromedial aspect of lateral femoral condyle to anterior tibia eminence - Primary restraint to anterior tibial translation, secondary restraint to varus (in extension) and IR - Anteromedial bundle - tight in knee flexion, lax in extension - Tight in knee extension, lax in flexion |
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Transverse meniscal ligament |
- connect both anterior horns of menisci to tibia - stabilizes menisci, can be torn/injured |
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Ligamentum mucosum (anterior plica) |
- distal femoral articulation to anterior tibial plateau - Synovial remnant. Covers anterior notch (ACL) - may need to debrided for full visualization |
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Infrapatellar fat pad |
- posterior to patellar, anterior to intercondylar notch - Cushions patellar tendon - Can become fibrotic or impinged on causing knee pain (Hoffa syndrome) |
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PCL |
- lateral aspect (in notch) of medial femoral condyle to post proximal tibia (below joint line) - primary restraint to posterior tibial translation - secondary restrait to varus, valgus, and ER |
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PCL anterolateral bundle |
- anterior origin on condyle, lateral on tibia - tight in knee flexion, lax in extension |
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PCL posteromedial bundle |
- post origin on condyle, medial on tibia - tight in knee extension, lax in flexion |
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Meniscofemoral ligaments |
- posterior lateral meniscus to MFC and/or PCL - Variably present. Rarely are both present |
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Ligament of murphey |
- meniscofemoral ligament anterior to PCL - contributes to PCL function and stabilizes meniscus |
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Ligament of Wrisberg |
- meniscofemoral ligament posterior to PCL - contributes to PCL function and stabilizes meniscus |
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Oblique popliteal ligament |
- origin on semimembranosus insertion on posterior tibia; inserts on posterior LFC and capsule - Tightens posterior capsule when semimembranosus contracts; considered part of posteromedial border |
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Superficial/First layer of Femorotibial joint - Lateral and Posterior structures |
- IT band - Biceps femoris |
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IT Band |
3 insertions - Gerdy's tubercle - patella and patellar tendon - supracondylar tubercle - Stabilizes lateral knee - accessory anterolateral ligament. Post in flex (ER tibia), ant in extension |
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Biceps femoris |
- 2 heads insert on fibular head, lateral to LCL - lateral stabillizer, also externally rotates tibia |
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Middle/Second layer of Femorotbial joint |
- laterally patellofemoral ligament: lateral femur to lateral edge of patella. May need release if tightened and causing patellar tilt and abnormal lateral articular cartialge wear - Lateral patellar retinaculum: Vastus fascia to tibia and patella |
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Deep/Third layer of Femorotibial joint |
Superficial lamina - LCL - Fabellofibular ligament Deep Lamina - popliteus - popliteofibular ligament - capsule - arcuate ligament |
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LCL |
- lateral epicondyle to medial fibular head - primary restraint to varus stress, also resists ER |
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Fabellofibular ligament |
- fibular head to fabella, usually within arcuate ligament - variably present, also called short collateral |
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Popoliteus muscle and tendon |
- inserts anterior and distal to LCL origin - resists tibia ER, varus, and posterior translation |
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Popliteofibular ligament |
- popliteus musculotendinous junction to fibula head - primary static restraint to ER |
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Deep Lamina Knee capsule |
- femur to tibia - extends 15 mm below the joint line - reinforced by other structures, resists varus and ER |
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Arcuate ligament |
- lateral arm: fibular head to posterior femur - medial arm: posterior lateral femur, blends with OPL - Variably present, Y shaped: two arms. Lateral arm covers popliteus supports posterolateral knee |
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Lateral meniscus |
- to lateral plateua via coronary ligaments - gives concavity to the convex lateral plateau |
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Lateral head of gastrocnemius |
- origin is on posterior lateral condyle - Adds dynamic support to posterolateral knee |
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Inferior lateral artery |
passes between the superficial and deep lamina of the third layer of posterolateral corner |
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Focus of surgical reconstruction in knee |
- LCL - popliteus - popliteofibular ligament |
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Most of the posterolateral structures in knee act as |
stabilizers to varus and ER forces - also secondary stabilizers to posterior translation |
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Arcuate complex refers to |
posterolateral stabilizing structures including: - LCL - arcuate ligament - popliteus - lateral gastrocnemius |
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Femorotibial joint - Medial structures (Superficial) |
- Sartorius: becomes fascial layer at insertion at Pes. Covers other tendons at Pes insertion - Fascia: deep fascia from thigh continues to knee, blends w/ retinaculum (ant) and capsule (post) |
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Femorotibial joint - medial structures (middle layer) |
- superficial medial collateral - posterior oblique ligament -medial patellofemoral ligament - medial patellar retinaculum - semimembranosus |
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Superficial medial collateral ligament |
- Medial epicondyle to tibia (deep to Pes) - Broad insertion is 5-7 cm below joint line - Primary restraint to valgus force (esp at 30 deg) - Secondary stabilizer to anterior translation and IR |
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Posterior oblique ligament |
- adductor tubercle (post to MCL) to posterior tibia, PH of medial meniscus and capsule - Static stabilizer against valgus. Lax in flexion but tightens dynamically due to semimembranosus |
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Medial patellofemorial ligament |
- medial patella to medial femoral epicondyle - primary static stabilizer against patella lateralization, may need repair/reconstruction after dx |
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Medial patellar retinaculum |
- continuous w/ vastus fascia to tibia and patella - can also be injured in lateral patellar subluxation |
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Semimembranosus |
- inserts posteromedial on tibia - gives posteromedial support |
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Femorotibial joint - medial structures (Deep) |
- Deep medial collateral ligament - Capsule |
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Deep MCL |
- inserts on medial meniscus and tibia plateau - Stabilizes meniscus. Also known as medial capsular ligament or middle 1/3 capsular ligament - Meniscofemoral fibers: femur to meniscus - Meniscotibial fibers: tibia to meniscus |
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Medial knee capsule |
- femur to tibia, extends 15 mm below joint - reinforced by other posteromedial structures |
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Medial meniscus |
- attached firmly to medial tibial plateau via coronary ligaments - posterior horn is secondary stabilizer to anterior translation - becomes primary in ACL |
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Medial head of gastrocnemius |
- origin of posteromedial femur - provides some minor additional dynamic support |
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Gracilis and semitendinosus tendons |
between layers 1 and 2 - act as secondary dynamic medial stabilizers |
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Posterior oblique ligament (POL) is a confluence of |
- layers 2 and 3 tissues that are indistinct in posteromedial aspect of knee |
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Meniscus: Fibrocartilage discs |
- interposed in femorotibal joints between femoral condyles and tibial plateaus - have a triangular cross section - thickest at periphery then tapering to a central edge - histologically made up of collagen (type 1), fibrochondrocytes, water, proteoglycans, glycoproteins, elastin |
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3 layers of meniscus |
- superficial layer: woven collagen fiber patter - surface layer: randomly oriented collagen fiber pattern - middle (Deepest) layer: circumferential (longitudinal) oriented fibers. These fibers dissipate hoop stresses. Radial fibers act as ties to hold circumferential fibers |
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Meniscus vascular supply |
- superior and inferior medial/lateral geniculate arteries. - Form perimeniscal plexus in synovium/capsule. - Peripheral portion is vascular vessels from the perimeniscal plexus - central, avascular 2/3 of menisci receive nutrition from synovial fluid |
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Meniscus red zone |
3 mm from capsular junction (most tears will heal) |
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Red/white meniscus zone |
3-5 mm from capsular junction (most tears will not heal) |
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Meniscus white zone |
> 5 mm from capsular junction (most tears will not heal) |
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Medial meniscus |
C shaped, less mobile, firmly attached to tibia (via coronary ligaments) and capsule via deep MCL at midbody |
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Lateral meniscus |
- circular, more mobile, loose peripheral attachments, no attachment at popliteal hiatus (where popliteus tendon enters joint) |
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Meniscus function |
- load transmission and shock absorption - joint congruity and stability - joint lubrication - joint nutrition - proprioceptio |
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Menisci load transmission and shock absorption |
- the menisci absorb 50% (extension) or 85% (flexion) of forces across femorotibial joint. - - -----Transmission of this load to the menisci helps protect the articular cartilage |
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Menisci joint congruity and stability |
- create congruity between curved condyles and flat plateaus which increases stability - menisci also act as secondary stabilizers to translation |
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Menisci joint lubrication |
menisci help distribute synovial fluid across the synovial fluid across to articular surfaces |
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Menisci joint nutrition |
menisci absorb, then release synovial fluid nutrients for the cartilage |
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Menisci proprioception |
- nerve endings provide sensory feedback to joint position |
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Patellofemoral joint function |
- composed of quadriceps tendon, patella/tendon, patellar stabilizing ligaments - extensor mechanism of knee - increases moment arm from joint axis - stability of patella in trochlea groove - hypoplastic LFC or patellar ridge, a flat trochlea, increased Q angle can predispose to patellar dislocation - patella begins to engage trochlae at 20 deg flexion and fully engaged at 40 deg - articulation point moves proximally w/ increased flexion - |
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Patellofemoral joint reaction forces |
- 3 x body weight with stairs - 7 x body weight with deep bendings - articular cartialge is up to 5 mm (thickest in body) to accomodate for these high forces |
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Quadriceps tendon |
- quadriceps to superior pole of patella - can rupture with eccentric contraction |
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Patellar tendon/ligament |
- inferior pole of patella to tibial tuberosity - can rupture w/ eccentric contraction |
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Patellofemoral ligaments (Medial/lateral) |
- femoral epicondyles to medial/lateral patella - primary stabilizers of patella (MPFL) |
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Patellotibial ligaments (med and lat) |
- tibial plateaus to medial/lateral patella - minor patellar stabilizer |
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Patellomeniscial ligament (med and lat) |
- patella to periphery of menisci - secondary stabilizers of patella |
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Patellar retinaculum (med and lat) |
- inserts on both the femur and tibia - minor patellar stabilizer |
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Patella position |
- can be eval on lateral radiograph (30 degree felxion) w/ insall ration (patella diagonal length/patellar tendon length - Normal ration is 1.0 (0.8 to 1.2) - > 1.2 indicates patella baja - < 0.8 indicates patella alta |
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Dynamic patellar stabilizers |
- quads - adductor magnus - ITB - vastus medialis/lateralis |
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Primary restraint to lateral patellar dislocation |
medial patellofemoral ligament |
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Anterior tibiofibular ligament |
- proximal tibiofibular joint - fibular head to anterior lateral tibia - broader and stronger than posterior ligament |
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Posterior tibioibular ligament |
- proximal tibioibular joint - fibular head to posterior lateral tibia - weaker than anterior ligament |
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Interosseous membrane |
- lateral tibia to medial fibula - stout fibrous membrane separates anterior and posterior compartments - disrupted in Maisonneuve fx |
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Proximal tibiofibular joint |
- joint has minimal motion - dislocation or disruption of this joint indicates high energy trauma to knee region |
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Knee arthrocentesis/injection |
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Knee injection |
- place patient in seated position w/ knee flexed - prep skin - prepare syringe w/ local/steroid mixture on 21/22 gauge needle - palpate soft spot b/w border of patellar tendon, tibal plateau, and femoral condyle - horizontally insert the needle into soft spot, aiming approx 30 degree to midline toward intercondylar notch. - gently aspirate to confirm not in vessel - inject solution into knee - withdraw needle |
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Knee aspiration/arthorocentesis |
- place patient supine w/ knee fully extended - palpate borders of patella and femoral condyle - prep skin - insert needle, usually 21 or 18 guage, horizontally into suprapatellar pouch at level of superior pole of patella - aspirate fluid into syringe - gently compress knee to milk fluid to pouch for aspiration |
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Knee pain: young age |
- trauma: ligamentous or meniscal injury, tx |
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knee pain: middle aged, elderly |
arthritis |
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Acute knee pain |
- Trauma: fx, dislocation, soft tissue injury, septic bursitis, arthritis |
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Chronic knee pain |
- arthritis, infection, tendinitis, overuse, tumor |
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Anterior knee pain |
- quadriceps or patellar tear/tendinitis - prepatellar bursitis - patellofemoral dynsfunction |
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posterior knee pain |
- meniscal tear (posterior horn) - baker's cyst - PCL injury |
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lateral knee pain |
- meniscus tear - collateral ligament injury - arthritis - ITB syndrome |
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medial knee pain |
- meniscus tear - collateral ligament injury - arthritis - pes bursitis - tumor, infection |
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Knee stiffness w/o locking |
- arthritis - effusion (trauma,infection) |
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Knee stiffness w/ locking/catching |
- loose body - meniscal tear - arthritis - synovial plica |
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Intraarticular knee swelling |
- infection - trauma - osteochondritis - meniscal tear - ACL/PCL injury |
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Extraarticular knee swelling |
- collatearl ligament injury - bursitis - contusion - sprain |
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Acute swelling post injury |
- Hours: ACL injury - Subacute: meniscus, OCD |
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Acute swelling without injury |
- Infection: prepatellar bursitis and septic joint |
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Knee giving away/collapse |
- cruciate or collateral ligament injury/ extensor mechanism injury |
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Giving away/pain |
patellar subluxation/dislocation: pathologic plica, OCD |
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Trauma: valgus force |
MCL injury - +/- terrible triad: MCL, ACL, medial meniscus |
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Trauma: varus force |
LCL or posterolateral corner injury |
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Trauma: flexion/posterior |
PCL injury |
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Trauma: twisting |
Non contact ACL injury Contact: multiple ligaments |
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Trauma: popping noise |
- Cruciate ligament especially ACL - osteochondral fx - meniscal tear |
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Pain w/ agility/cutting sports |
- Cruciate (ACL) or collateral ligament |
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pain w/ running, cycling |
patellofemoral etiology |
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pain w/ squatting |
meniscus tear |
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Pain w/ walking |
distance able to ambulate equates w/ severity of arthritic disease |
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Neurologic knee symptoms |
- neurologic disease - trauma - consider L spine etiology |
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Systemic sxs - fever, chills |
- infection - septic joint - tumor |
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Varus thrust |
can indicate LCL or posterolateral corner injur |
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patella tracking |
maltracking can lead to patellofemoral syndrome |
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flexed knee gait |
from tight achilles tendon or hamstrings, can lead to patellofemoral syndrome |
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Anterior knee alignment |
- normal knee is clinically neutral (6 degree valgus) - evaluate while weight bearing - variation can be developmental or post traumatic |
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Genu valgum (knock knee) |
Can predispose to lateral compartment DJD, patella, instability/maltracking |
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Genu varum (bow leg) |
- can predispose to medial compartment DJD, ligamentous incompetency |
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Q angle |
- Angle from ASIS to mid patella to mid tubercle - NI: male < 10 degrees, female < 15 degrees - increased angle predisposes to patellar subluxation, patellofemoral symptoms |
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Anterior knee swelling |
- Prepatellar: prepatellar burisits - intraarticular effusion: arthritis, infection - trauma: intraarticular fx, meniscal tear, ligament rupture |
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Enlarged tibial tubercle |
- my be result of osgood schlatter disease |
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Posterior knee mass |
Bakers cyst |
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Lateral knee alignment |
evaluated while weight bearing |
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Lateral recurvatum |
possible PCL injury |
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Patella position |
best evaluated radiographically w/ Insall ratio |
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High riding patella |
patella alta: can predispose to patella instability |
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Low riding patella |
patella baja - usually post traumatic or post surgical (possible arthrofibrosis) |
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Quadricep injury |
atrophy can reult from injury, post op, or neuro |
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Vastus medialis |
VMO atrophy may contribute to patellofemoral symptoms |
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Patella palpation |
tenderness at distal pole: tendinitis (jumpers knee) |
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Tibial tubercle palpation |
- tenderness w/ osgood schlatter |
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Quadriceps tendon |
defect - tendon rupture, tendinitis, tenderness |
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Patellar tendon |
- Defect: tendon rupture, tenderness, tendinitis |
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Compress suprapatellar pouch |
- Ballotable patella (effusion) - arthritis, trauma, infection |
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Pre patellar bursa |
edematous/tender bursa indicate correlating bursitis |
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Pes anserine bursa |
tenderness indicates bursitis |
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Retinaculum/plica |
thickened, tender plica is pathologic |
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Medial joint line and MCL |
tenderness: medial meniscus tear or MCL injury |
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Lateral joint line and LCL |
Tender: lateral meniscus tear or LCL injury |
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ITB/LFC |
pain or tightness is pathologic |
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Popliteal fossa |
mass consistent with Baker's cyst, popliteal aneurysm |
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Knee F/E |
- supine: heel to buttocks then straight - Normal flex: 0-135 degrees - Extend 0-15 degrees - Flexion contracture common in OA/DJD - exentsor lag (last 20 degrees) = weak quads - decreased extension with effusion - patellar tracking pain/creptius = abnormal racking |
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Tibial IR and ER |
- stabilize femur, rotate tibia - normal 10-15 degrees |
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Femoral nerve/Saphenous L4 sensory |
- medial leg |
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Peroneal nerve L5 sensory |
- Lateral sural = proximal lateral leg - superficial branch = distal lateral leg |
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Tibial nerve S1: medial sural |
proximal posterolateral leg |
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Sural nerve sensory |
distal posterolateral leg |
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Femoral nerve motor |
Knee extension - weakness = quadriceps |
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Sciatic - tibial branch |
Knee flexion - weakness = biceps LH |
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Sciatic peroneal branch |
knee flexion - weakness = biceps SH |
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Peroneal (deep) n L4 - motor |
Foot dorsiflexion - weakness = tibialis anterior |
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Peroneal (superficial) L5 motor |
hallux dorsiflexion - wekaness - extensor hallucis longus |
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Patellar reflex |
L4 |
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Patella dispacement test |
- patellofemoral joint - translate patella medially and laterally - Divide patella into 4 quadrants. Patella should translate 2 quadrants in both directions - decreased mobility indicates a tight retinaculum |
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Patellar apprehension test |
- relax knee, push patella laterally - pain/apprehension of subluxation: patellar instability or medial retinaculum/MPFL injury |
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J sign test |
- actively extend knee from flexed position - lateral displacement of patella in full extension: maltracking |
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Patella compression/grind |
- extend knee, fire quads, compress patella - Pain: chondromalacia, OCD, PF arthritis, DJD of patella |
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Joint line tenderness |
- meniscal - palpate both joint lines - most sensitive exam for meniscal tear when tender |
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McMurray test |
- Flex/varus/ER knee then extend: pop or pain suggests medial meniscal tear - Flex/valgus/IR knee, then extend: pop or pain suggest lateral meniscal tear |
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Apley's compression test |
- prone, knee 90 degrees, compress and rotate - pain or pop indicates meniscal tear |
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Lachman |
- flex knee 20-30 degrees, anterior force on tiba - Laxity indicates ACL injury = most sensitive exam for ACL rupture - Grade 1: 0-5 mm - Grade 2: 6-10 mm - Grade 3: > 10 mm - A: good - B: no end point |
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Anterior drawer test |
- flex knee 90 degrees - anterior force on tibia - laxity/anterior translation: ACL injury |
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Pivot shift |
Supine, extend knee, IR, valgus force on proximal tibia, then flex knee - Clunk w/ knee flexion indicates ACL injury - If ACL is deficient, the tibia starts subluxated and reduces w/ flexion, causing clunk |
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Posterior drawer |
- flex knee 90 degrees, posterior force on tibia - posterior translation: PCL injury |
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Posterior sag |
- supine, hip 45 degrees, knee 90 degrees, view laterally - Posterior translation of tibia on femur indicates PCL injury |
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Quadriceps active |
- supine, knee 90 degrees, fire quads - posteriorly subluxated tibia translates anteriorly if PCL is deficient |
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Reverse pivot shift |
- supine, flex knee 45 degrees, ER, valgus force on proximal tibia, then extend knee - Clunk w/ knee extension indicates PCL injury (if PCL is deficient, the tibia is subluxated posteriorly, then reduces w/ extension causing clunk) |
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Valgus stress test |
- lateral force to knee at 30 degrees, then 0 degrees - Laxity at 30 degrees - MCL injury - 0 degrees - MCL and cruciate ligament injury |
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Varus stress test |
- medial fore to knee at 30 degrees, then 0 degrees - Laxity at 30 degrees - LCL injury - Laxity at 0 degrees - LCL and cruciate ligament injury |
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Prone ER at 30 degrees and 90 degrees (Dial) |
- prone, ER both knees t 90 degrees, then 30 degrees - increased ER at 30 degrees - posterolateral corner injury - increased ER at 90 degrees- PLC/PCL injuries |
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ER recurvatum |
supine, legs straight, raise legs by toes - recurvatum varus, and IR of knee indicates PCL injury |
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Slocum test |
- Knee 90 degrees, IR tibia 30 degrees, anterior force: displacement = ACL/PLC injury - knee 90 degrees, ER tibia 30 degree, anterior force: displacement = ACL, MCL, POL |
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Posterior lateral drawer |
- knee 90 degrees, ER tibia 15 degrees, posterior force - laxity indicates posterolateral corner and/or PCL injury |
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Posterior medial drawer |
- knee 90 degrees, IR tibia 30 degrees, posterior force - Laxity indicates PCL and MCL/POL injury |
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Lateral femoral condyle origins |
- lateral gastrocnemius - plantaris - popliteus (ant and inferior to LCL) - LCL |
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Medial femoral condyle origins |
medial gastrocnemius |
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Fibular head origins |
soleus |
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Proximal tibia origins |
- tibialis anterior - extensor digitorum longus |
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Medial femoral condyle insertions |
- adductor magnus - MCL |
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Femoral head insertions |
- Biceps femoris - LCL - popliteofibular ligament - arcuate ligament - fabellofibular ligament |
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Proximal tibia insertions |
- Quads (tibial tubercle) - ITB - Pes tendons - Semimembranosus - popliteus - MCL |
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Anterior knee compartment muscles |
- TA - extensor hallucis longus - extensor digitorum longus - peroneus tertius |
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Anterior knee compartment neurovasculature |
- deep peroneal nerve - anterior tibial a/v |
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Lateral knee compartment |
- peroneus longus/brevis - superficial peroneal nerve |
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Superficial posterior knee compartment |
- gastrocnemius - soleus - plantaris |
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Deep posterior knee compartment |
- posterior tibialis - flexor hallucis longus - flexor digitorum longus - popliteus - tibial nerve - posterior tibial a/v - peroneal a/v |
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Anterolateral fasciotomy |
centered over intermuscular septum between anterior and lateral compartments |
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Medial fasciotomy |
centered over posterior tibial border/septum between superficial and deep posterior compartments |
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Tibialis anterior |
- origin: proximal lateral tibia (Gerdy's) - insertion: median cuneiform, palantar 1st metatarsal base - deep peroneal nerve - dorsiflex, invert foot - Test L4 function |
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Extensor hallucis longus |
- origin: medial fibula, interosseous membrane - insertion: Base of distal phalanx of great toe - deep peroneal nerve - dorsiflex, extend great toe - test L5 function |
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Extensor digitorum longus |
- origin: lateral tibia condyle, and proximal tibia - insertion: base of middle and distal phalanges (4 toes) - deep peroneal nerve - dorsiflex, extend 4 lateral toes - single tendon divides into four tendons |
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Peroneus tertius |
- origin: distal fibula, interosseous membrane - insertion: base of 5th metatarsal - deep peroneal nerve - dorsiflex, evert foot - often adjoined to the EDL |
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Peroneus longus |
- origin: proximal lateral fibula - insertion: plantar medial cuneiform, 1st metatarsal base - superficial peroneal nerve - Plantar flex foot - Test S1 motor function, runs under the foot |
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Peroneus brevis |
- origin: distal lateral fibula - insertion: Base of 5th metatarsal - superficial peroneal nerve - Evert foot - Can cause avulsion fx at base of 5th metatarsal, has most distal muscle belly |
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Gastrocnemius |
- origin: lateral and medial femoral condyles - insertion: Calcaneus via achilles - tibial nerve - plantar flex foot - Test S1 motor function, two heads - fabella is in tendon of lateral head |
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Soleus |
- origin: posterior fibular head/soleal line of tibia - Insertion: calcaneus via achilles tendon - Tibial nerve - plantar flex foot - fuses to gastrocnemius at achilles tendon |
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Plantaris |
- origin: lateral femoral supracondylar line - insertion: calcaneus - tibial nerve - plantar flex foot - long tendon can be harvested for tendon reconstruction |
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Popliteus |
- origin: lateral femoral condyle (anterior and distal to LCL) - proximal posterior tibia - Tibial nerve - IR tibia/knee (during swing phase) - Origin is intra-articular, primary restraint to ER of knee |
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Flexor hallcuis longus |
- origin: posterior fibula - insertion: base of distal phalanx of great toe - tibial nerve - plantar flex great toe - Test S1 motor function |
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Flexor digitorum longus |
- origin: posterior tibia - insertion: bases of distal phalanges of 4 toes - tibial nerve - plantar flex lateral 4 toes - at ankle, tendon is just anterior to tibial artery |
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Tibialis posterior |
- origin: posterior tibia, fibula, interosseous membrane - insertion: plantar navicular cuneiform, MT bases - Tibial nerve - Plantar flex and invert foot (in heel off phase) - Tendon rupture/degeneration can cause acquired flat foot |
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Saphenous nerve L2-4 course |
- Branch of femoral nerve, enters leg posteromedially, superficial to sartorial fascia - at risk in direct medial approach - gives off infrapatellar branch (at risk in anteromedial/midline approaches) - descends in the medial leg |
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Saphenous nerve L2-4 |
- sensory: infrapatellar region via infrapatellar branch and medial leg via medial cutaneous nerves - motor: none |
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Tibial nerve L4-S3 course |
- descends b/w heads of gastrocnemius into leg - posterior to posterior tibialis muscle in posterior compartment to ankle just posterior to medial malleolus between FDL/FHL tendons |
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tibial nerve sensory |
- proximal posterolateral leg via medial sural nerve |
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tibial nerve motor |
- plantaris - gastrocnemius - soleus via nerve to soleus - popliteus via nerve to popliteus - posterior tibialis - flexor digitorum longus - flexor hallucis longus |
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Common peroneal nerve course |
- L4-S2 - divides from sciatic nerve in distal posterior thigh - runs posteroinferior to biceps femoris - around fibular neck (can be compressed or injured) then divides into 2 branches |
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Common peroneal nerve sensory |
- proximal lateral leg via lateral sural nerve |
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Deep peroneal nerve |
- runs in anterior compartment of leg w/ anterior tibial artery - posterior to tibialis anterior on interosseous membrane |
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Deep peroneal nerve - motor |
- tibialis anterior - extensor hallucis longus - extensor digitorum longus - peroneus tertius |
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Superficial peroneal course |
- runs in lateral compartment of leg - crosses anteriorly 12 cm above lateral malleolus (injured in lateral ankle approach) to dorsal foot, then divides into two branches |
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Superficial peroneal nerve sensory/motor |
- sensory: anterolateral leg - motor: peroneus longus/brevis |
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Sural nerve |
- formed from medial sural cutaneous (tibial nerve) and lateral sural (cutaneous) run subQ in posterolateral leg - crosses achilles tendon 10 cm above insertion then to lateral feet - Sensory: posterolateral distal leg |
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Popliteal artery course |
- begins at adductor hiatus and runs through popliteal fossa - posterior to PCL - divides at popliteus muscle |
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Popliteal artery branches |
- superior medial and lateral geniculate - inferior medial and lateral geniculate - middle geniculate - anterior and posterior tibial arteries |
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Popliteal artery supply |
- SLGA at risk in lateral release - ILGA separates lateral knee layer 3 ligaments/structures - Supplies ACL,PCL, and snynovium (middle) - terminal branch of popliteal arteries (A/P tibial) |
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Anterior tibial artery course |
- passes b/w the two heads of the posterior tibialis into anterior compartment - lies on interosseous membrane w/ deep peroneal nerve |
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Anterior tibial artery branches |
- Anterior tibial recurrent: supplies and anastamoses at knee - Circumflex fibular: supplies fibular head and lateral knee - Anterior medial/lat malleolar: anterior potion of malleoli - Dorsalis pedis: terminal branch in foot |
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Posterior tibial artery course |
- runs with tibial nerve in deep posterior compartment posterior to posterior tibialis muscle to the ankle - where it lies between the FDL and FHL tendons posterior to medial malleolus |
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Posterior tibial artery branches: |
- posterior tibial recurrent: supplies and anastamoses at knee - Peroneal artery: supplies lateral compartment - Perforating muscular brances: muscles of post compartment - Posterior medial malleolar: supplies posterior medial malleolus - Medial calcaneal: supplies medial calcaneus/heel - Medial/lateral plantar: terminal branches in foot |
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Peroneal artery |
- branches from posterior tibial artery, runs between PT and FHL muscles in posterior compartment - Posterior lateral malleolar branch: supplies posterior lateral malleolus - Lateral calcaneal artery: supplies lateral calcaneus/heel |
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OA - knee |
- primary/idiopathic or secondary (post-trauma) - loss/deterioration of articular cartilage - can affect 1 (medial #1) of all 3 compartments |
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Knee OA H&P |
- Hx: older, decreasing activity level. Pain w/ weight bearing activities - PE: effusion, joint line tenderness, +/- contracture or deformity (varus #1) |
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Knee OA XR |
Arthritis series - joint space narrowing - osteophytes - subchondral sclerosis - subchondral cysts Alignment views |
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Knee OA tx |
- NSAIDs, activity mod - PT, brace, cane - Glucocorticosteroid injections - Unicompartmental: HTO, unicompartment arthoplasty - Tricompartmental: TKA |
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Inflammatory knee arthritis |
- multiple types: RA, gout, seronegative - in RA, synovitis/pannus formation destroys cartilage and eventually whole joint |
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Inflammatory knee arthritis H&P |
- Hx: usually younger pt. Pain often mutiple joints - PE: effusion, +/- warmth, decreased ROM and deformity |
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Inflammatory arthritis work up |
- XR: arthritis series: joint narrowing, joint erosions, ankylosis, joint destruction - LABS: CBC, RF, ANA, CRP, crystalis culture |
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Inflammatory arthritis tx |
- early: manage medically Late - nonop - like OA - synovectomy - TKA |
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Patellofemoral syndrome |
- pain in patellofemoral joint - contributing factors: overuse, subtle instability or malalignment, quad weakness - Chondromalacia may be present |
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Patellofemoral syndrome H&P |
- hx: young female and athletes. Pain w/ activities and prolonged sitting - PE: + patella compression, +/- increased Q angle or J sign |
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Patellofemoral syndrome XR |
- AP and notch: eval for OCD, OA - Lateral: OA and insall ratio - Sunrise: subluxation or tilt, OA, OCD |
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Patellofemoral syndrome tx |
- NSAIDs, activity mod - PT, ROM, quad strengthening, hamstring stretching, +/- foot orthoses - patella realignment |
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|
Chondromalacia patellae |
- softening or wear of articular cartilage of patella - term often misused to imply any anterior knee pain |
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Chondromalacia patellae H&P |
- usually younger pts, pain often multiple joints - PE: effusion, decreased ROM and deformity |
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|
Chondromalacia patellae XR |
- AP and notch: eval for OA,OCD - lateral: OA and insall ratio - Sunrise: subluxation or tilt, OA, OCD |
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Chondromalacia patellae tx |
- NSAIDs, acitivity mod - PT - Arthroscopic debridement/chondropasty may help |
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|
Lateral patellar compression syndrome |
- overloading of lateral facet during flexion - due to tight lateral structures |
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|
Lateral patellar H&P |
- Hx: usually younger pts - PE: PF pain, decreased mobility/patella glide |
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|
Lateral patellar compression syndrome XR |
- Sunrise merchant: evaluate for lateral patellar tilt |
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|
Lateral patellar compression syndrome tx |
- PT: stretch lateral tissues, quad strengthening, +/- taping or centralizing brace - arthroscopic lateral release |
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|
ITB syndrome |
- ITB rubs on lateral femoral condyle - common w/ runners/ cyclists |
|
|
ITB H&P |
- Hx: pain w/ activity - PE" lateral femoral condyle, TTP w/ knee at 30 degrees |
|
|
ITB syndrome XR |
- AP:lateral: normal, r/o tumor |
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ITB syndrome tx |
- NSAIDs, activity mod, stretching - Partial excision rare |
|
|
Patelalr instability |
- subluxation or dislocation of patellae (lateral #1) - associated w/ anatomic variants - MPFL is key structure |
|
|
Patellar instability H&P |
- Hx: pain and patella instability - PE: + patellar apprehension, +/- increased Q angle, genu valgum, femoral anteversion |
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|
Patellar instability workup |
- XR: eval for fx and patella position (lateral and/or patella alta) - MRI: eval MFPL if acute |
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|
Patellar instability tx |
- Acute: MFPL repair - Recurrent: PT, brace, patellar alignment surgery |
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|
Patellar tendinitis |
- seen in jumpers - microtears at tendon insertion at distal pole |
|
|
Patellar tendinitis H&P |
- Sports, anterior knee pain - PE: patellar inferior pole TTP |
|
|
Patellar tendinitis work up |
- XR: AP/lateral: normal - MR: increased signal at insertion (inferior pole) or intrasubstance |
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|
Patellar tendonitis tx |
- NSAIDs, stretch and strengthen quads and hamstrings - Surgical debridement - rare |
|
|
Plica |
- fold in synovium (embryonic remnant) becomes thickened or inflamed - medial plica #1 |
|
|
Plica H&P |
- hx: anteromedial pain, +/- popping/catching - PE: tender, palpable plica, +/- snap w/ flexion |
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|
Plica work up |
- XR: knee series. eval for other pain sources - MRI: of questionable value |
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|
Plica tx |
- ice, NSAIDs - activity mod - arthroscopic debridement if symptoms persists |
|
|
Prepatellar bursitis |
- etiology: trauma or over use - housemaid's knee - inflammatory or septic |
|
|
Prepatellar bursitis H&P |
-hx: knee pain and swelling - PE: egg shaped swelling on anterior patella, TTP, +/- signs of infection |
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Pre patellar bursitis work up |
- XR: knee series usually normal - LAB: CBC, ESR, +/- aspirate: gram stain and cell count |
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Prepatellar bursitis tx |
- inflammatory: ice, NSAIDs, knee pads, rest, +/- aspiration - bursectomy if persists - septic: bursectomy, abx |
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ACL injury |
- mechanism: twisting injury often non contact pivoting - associated w/ other injuries: meniscal tears, collateral ligament - common in female athletes |
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ACL H&P |
- Hx: twisting injury, pop, swelling, inability to continue playing - PE: effusion + lachman/anterior drawer/pivot shift |
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ACL workup |
- XR: knee series (Segond fx is pathognomonic for ACL) - MR: absent/detached ACL, +/- bone bruise (middle LFC- posterior lateral tibial plateau - Arthrocentesis: hemiarthrosis |
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ACL tx based on functional stability |
- Stable/low demand pt - activity mod, PT, brace - unstable/athletes/active: surgical reconstruction w/ grafts from BTB, hamstring, allograft |
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ACL complications |
- arthrofibrosis - failure/reoccurence |
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Posterolateral corner injury |
- mechanism: direct blow or hyperextension/varus injury - LCL, popliteus, popliteofibular ligaments are injured - Can be associated w/ PCL injury |
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Posterolateral corner injury H&P |
- Hx: trauma, pain, instability - PE: +/- effusion, + prone ER test at 30 degrees, +/- posterolateral drawer and ER recurvatum tests |
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Posterolateral corner workup |
- XR: knee series. Avulsions can occur (fibular head) - MRI: evaluate all ligaments and other soft tissues |
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Posterolateral corner tx |
- Nonoperative (low grade): brace and PT - Surgical repair: acute grade 3 - Surgical reconstruction: chronic or combined injury, HTO if varus |
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PCL injury |
- mech: anterior force on tibia or sports hyperextension - associated w/ collateral and/or PL corner injuries |
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PCL injury H&P |
- Hx: trauma (dashboard) or sports injury, pain - PE: +/- effusion, + posterior drawer, quadriceps active test, and posterior sag |
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PCL work up |
- XR: knee series. look for avulsion fx - MR: confirms diagnosis. Evaluates meniscus and articular cartilage |
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PCL tx |
- Nonoperative: isolated (grades 1 and 2), brace and PT - Surgical reconstruction: failed nonop tx, combined injury, some isolated grade 3 |
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MCL injury |
- mechanism: valgus force - common in football - usually injured at femoral origin |
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MCL H&P |
- Hx: trauma, pain, instability - PE: tenderness at medial epicondyle along tendon. Pain/laxity w/ valgus stress |
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MCL workup |
- XR: knee series. Medial epicondyle avulsion can occur (Calcified = pelligrini-steida) - MR: confirms diagnosis |
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MCL tx |
- hinged knee brace - PT: ROM and strengthening - surgery: uncommon |
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LCL injury |
- mechanism: varus force - isolated injuries: rare - usually combined with PLC injury |
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LCL injury H&P |
- Hx: trauma, pain, instability - PE: lateral tenderness, pain/laxity w/ varus stress |
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LCL injury workup |
- XR: knee series. Fibular head avulsions can occur - MR: can confirm diagnosis |
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LCL tx |
- isolated injury: hinged brace - combined injury: surgical repair/reconstruction |
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Meniscus tear |
- Acute: young, twisting injury - Degenerative: older, +/- OA - multiple tear patterns - associated w/ other injuries (ACL rupture, OCD) - Medial > lateral ((3:1) posterior most common |
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Meniscus tear H&P |
- Hx: pain and swelling esp w/ flexion activities, +/- catching or locking (bucket handle tear) - PE: effusion, joint line tenderness, + McMurray or Apleys |
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Meniscus tear work up |
- XR: knee series usually normal. Early OA seen in pt with degnerative tears - MR: very sensitive for tears. "Double PCL" signed for displaced bucket handle tears |
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Meniscus tear tx |
- small/minimally symptomatic: treat conservatively - Peripheral tears (red zone) - repair (heal best w/ ACL reconstruction) - central tears (white zone) - partial meniscectomy |
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Osteochondral defect |
- spectrum: purely chondral to osteochondral lesions - traumatic or degenerative - osteochondritis dissecans is separate but similar entity |
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Osteochondral defect H&P |
- often young/active pt. Pain w/ WB, popping, catching - PE: inconsistent, +/- effusion, bony tenderness |
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Osteochondral effect work up |
- XR: Knee series 4 views: need 45 degree PA and notch views, consider alignment series - MR: good modality for purely chondral lesions |
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Osteochondral defect tx |
- Displaced OCD: internal fixation Chondral - debridement - microfracture - osteochondral transfer - chondrocyte implantation |
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Quadriceps tendon rupture |
- mechanism: eccentric contraction or indirect trauma - Patients usually 40 yo - usually at musculotendinous junction |
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Quadriceps tendon rupture H&P |
- Hx: older, fall/trauma - PE: effusion, palpable defect above patella. Inability to do or maintain straight leg raise |
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Quadriceps tendon rupture work up |
- XR: knee series. look for patella baja - MR: will show tendon tear. Usually not needed. May be helpful in partial tears |
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Quadriceps tendon rupture tx |
- acute: primary surgical repair - chronic: surgical reconstruction (tendon lengthening or allograft procedure) |
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Patellar tendon rupture |
- mech: direct or indirect (eccentric load) trauma - patients usually < 40 yo - associated w/ underlying tendon and/or metabolic disorder |
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Patellar tendon rupture H&P |
- Hx: youger patients, trauma, loss of knee extension - PE: effusion, palpable defect in tendon. Cannot do straight leg raise |
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Patellar tendon rupture work up |
- XR: knee series. look for patella alta - MR: will show tendon tear. Usually not needed. MAy be helpful in partial tears |
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Patellar tendon rupture tx |
- acute: primary surgical repair - chronic: surgical reconstruction (tendon lengthening or allograft procedure) |
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Knee tumors |
- #1 in adolescents: osteosarcoma - #1 in adults: chondrosarcoma - #1 benign: giant cell tumor |
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TKA general info |
- Goals: alleviate pain, maintain personal independence, allow perfomance of ADLs - Restore mechanical alignment, restore joint line, balance soft tissues - common procedure w/ high satisfaction rate for primary procedure |
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TKA Materials - Femur component |
- cobalt-chrome commonly used for femoral bearing surface w/ titanium stem |
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TKA material - tibial component |
does not articulate w/ femoral component - often made of titanium |
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TKA material: tibial tray insert |
articulates w/ femoral component, made of polyethylene - PE wears well but does produce microscopic particles that may lead to implant loosening/failure - PE should be at least 8 mm thick, cross linked for better wear, and sterilized in inert environment - congruent design improves wear rate and rollback - direct compression molding is preferred manufacturing technique - Cement = methylmethacrylate |
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Unconstrained prosthetic design |
most common for primary surgical procedures - PCL retaining CR: preserves femoral rollback for increased knee flexion but has increased PE wear - PCL substituting (Posterior stabilized): provides mechanical rollback, but may dislocate. Indicated for patellectomy, inflammatory arthritis, incometent PCL. Central post for stability |
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Constrained/non hinged prosthetic |
used for moderate ligament (MCL/LCL) deficiency - uses a central post to provide stability |
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Constrained/hinged prosthetic |
- used for global ligament deficiency - high wear and failure rates |
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TKA fixation |
- cement: most common - Biologic: bone ingrowth techniques. Theoretically have longer life but higher failure rates |
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TKA indications |
- Arthritis of knee - sxs - knee pain, worse w/ activity, gradual worsening over time, decreased ambulatory capacity - failed conservative tx |
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Absolute TKA contraindications |
- neuropathic joint - infection - extensor mechanism dysfunction - medically unstable patient (severe cardiopulmoanry disease) - patients may not survive procedure |
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Relative TKA contraindications |
- young, active patients. These patients can wear out the prosthesis many times in their lives |
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Knee osteotomy |
- Valgus knee/lateral compartment DJD: distal femoral varus producing osteotomy - Varus knee/medial compartment DJD: proximal tibia valgus producing osteotomy |
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Unicompartment arthroplasty |
- unicompartmental disease |
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Arthrodesis/fusion |
young laborers with isolated unilateral disease |
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TKA approaches |
- midline inscision w/ medial parapatellar arthrotomy is most common - minimally invasive incisions are also being used. Special equipment is often needed for smaller incision |
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TKA Bone Cuts |
- Cut femur and tibia perpendicular to mechanical axis - can use intramedullary (femur/tibia) or extramedullary (tibia) reference, restores mechanical alignment - bone removed from femur and tibia should be equal to that replaced by implants to maintain/restore joint line |
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TKA implants |
Trial implants are first inserted to test adequacy of bone cuts - implants should be best fit possible to native bone - Femur placed in 3 degrees of external rotation to accomodate a perpendicular bone cut of the proximal tibia (typically in 3 degrees of varus) |
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Femoral axis determined in 3 ways |
- epicondylar axis - posterior condylar axis - AP axis-perpendicular to trochlea |
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TKA balancing: sagittal plane |
- goal is to make flexion and extension gaps equal - may need to cut more bone or add implant augments |
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TKA balancing: Coronal plane |
- soft tissues are of primary concern - rule is to release the concave side of deformity |
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TKA balancing: Varus deformity |
- release medial side - deep MCL - postmed capsule/semimembranous insertion - superficial MCL |
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TKA balancing: valgus deformity |
- release lateral side - lateral capsule - ITB tight in extension - popliteus tight in flexion - LCL |
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TKA balancing: polyethylene trial |
knee should be stable and well balanced with the trial polyethylene in place |
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TKA complications |
- patellofemoral complications are most common: patella maltracking, patellofemoral pain, patellar fracture - arthrofibrosis: may respond early to MUA |
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Extensor mechanism failure |
patellar tendon rupture or avulsion (difficult to repair/reconstruct) - patellar fracture |
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Infection s/p TKA |
- diagnose w/ labs and aspiration - prevention is mainstay - perioperative abx, meticulous prep/drape technique - Tx: acute/subacute: irrigation and debridement w/ PE exchange - Late tx: 1 or 3 stage revision |
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Loosening of TKA |
more common with biologic fixation - also caused by microscopic particles from PE wear |
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TKA neurovascular injury |
- Peroneal nerve: esp after mechanical axis correction of a valgus knee (nerve is stretched) - Superolateral geniculate artery: should be identified and cauterized |
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TKA medical complications |
- DVT and PE - initiate PPX |
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TKA periprosthetic fracture |
- femur: stable implant - nail or fixed angle device - femur: unstable implant - replace w/ longer stem that passes fx site |
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Genu varum |
- normal physiologic ages 0-2 - Pathologic: Blount's disease 1) infantile: < 3 yo, obesity, early walking 2) adolescent: insidious onset, > 8 yo |
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Genu Varum work up |
- Hx: parents notice a deformity - PE: unilateral or bilateral genu varum - XR: Tibia metadiaphyseal angle (TMDA): < 9 degrees is normal, > 16 pathologic |
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Genu varum tx |
- Physiologic: observation - Infantile: < 3 yo brace, > 3 yo osteotomy - Adolescent: hemiepiphysiodesis (open physis) or osteotomy (closed physis) |
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Genu valgum
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- normal (physiologic): ages 2-5 - Pathologic: skeletal tumors - Metabolic: renal osteodystrophy - Trauma, infection |
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Genu valgum work up |
- hx: parents notice a deformity - PE: unilateral or B/l genu valgum - XR: alignment XR: valgus is 6 degrees in normal adults |
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Genu valgum tx |
- physiologic: observation - Pathologic: hemiepiphysiodesis or osteotomy |
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Posteromedial Tibial bowing |
- congenital convexity of tibia - idiopathic, unilateral - deformity corrects but a leg length discrepancy usually results |
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Posteromedial tibial bowing work up |
- Hx: deformity present at birth - PE: foot appears dorsiflexed (calcaneovalgus), leg is bowed - XR: bowing of tibia and fibula |
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Posteromedial Tibial bowing tx |
- bowing resolves with growth - resultant leg length discrepancy: Mild (shoe lift), severe (hemiepiphysiodesis) |
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Anterolateral Bowing/Congenital Tibia Pseudoarthrosis |
- bowing of tibia, unknown etiology - associated w/ neurofibromatosis - anterolatearl bowing can lead to pseudoarthrosis |
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Anterolateral tibial bowing workup |
- Hx/PE: Leg deformity and disability, Bowed leg, +/- signs of neurofibromatosis - XR: reveals bowing or pseudoarthrosis |
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Anterolateral tibial bowing tx |
- Young/bowing tibia: full contact brace - Pseudoarthrosis: tibial nail/external fixation and bone growth - Amputation: only if surgical tx fails |
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Osgood Schlatter Disease |
- traction of apophysitis/osteochondrosis of tibial tubercle - repetitive stress to extensor mechanism |
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Osgood Schlatter work up |
- Hx: adolescent w/ knee pain, worse after activity - PE: tibial tubercle swollen and tender to palpation - XR: shows ossification center at tibial tubercle, +/- heterotropic ossification |
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Osgood Schlatter tx |
symptoms resolve w/ apophysis closure during adolescence - Activity mod/restriction - cast/brace if severe - excision of unfused ossicle |
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Tibial torsion |
- congenital internal rotation of tibia - associated w/ decreased intrauterine space and other packaging problems - most common cause of inteoing gait |
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Tibial torsion H&P |
- hx: 1-2yo, frequent tripping, pigeon toed - PE: intoeing gait, negative foot to thigh angle, medial foot progression angle, transmalleolar axis IR/medial w/ thigh/patella pointed forward |
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Tibial torsion tx |
- will spontaneously resolve - orthoses of no proven benefit - Supramedullar osteotomy if deformity persists into late childhood |
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Medial patellar surgical approach uses |
- ligament reconstruction - TKA - meniscectomy |
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Medial patellar surgical approach internervous plane |
- no planes: capsule is under skin |
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Medial parapatellar approach dangers |
- infrapatellar branch of saphenous nerve |
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Medial parapatellar approach comments |
- most commonly used approach - most/best exposure - neuroma may develop from cut nerve |
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Posterolateral Harmon Approach for Leg/Tib |
- fractures - non unions - technically difficult approach - bone grafting of non union |
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Posterolateral approach internervous plane |
- gastrocnemius/soleus/FHL (tibial n) - Peroneus longus/brevis (superfical peroneal) |
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Posterolateral Harmon approach dangers |
- lesser saphenous vein - posterior tibial artery |
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Anteromedial/Inferomedial arthroscopy portal |
- just above joint line, 1 cm inferior to patella, 1 cm medial to patellar tendon - dangers: anterior horn of medial meniscus - Most common portal to use instruments and viewing lateral compartment |
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Anterolateral/Inferolateral arthroscopy portal |
- just above joint line, 1 cm inferior to patella, 1 cm lateral to patellar tendon - danger: anterior horn of lateral meniscus - most common portal for arthroscope |
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Superolateral/superomedial arthroscopy portal |
- 2.5 cm above the joint line, lateral or medial to quadriceps tendon - used to view patellofemoral articulation, patella tracking, also inflow/outflow |
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Posteromedial arthroscopy portal |
- Flex knee to 90 degrees, 1 cm above joint line, posterior to MCL - dangers: saphenous nerve - used to view PCL, posterior horn of menisci, retrieve loose bodies |
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Posterolateral arthroscopy portal |
- flex knee, 1 cm above joint line, posterior to LCL - dangers: peroneal nerve - used to view PCL, posterior horns of menisci, retrieve loose bodies |
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Transpatellar arthroscopy portal |
- 1 cm below inferior pole of patella - dangers: patellar tendon - central joint and notch viewing |
