Leg/Knee Flashcards
3 functions of the patella
1) Enhances quadriceps pull (as fulcrum)
2) Protects knee
3) Enhances knee lubrication
What inserts on head of fibula?
LCL, Biceps femoris
What goes in groove of tibial head
Peroneal nerve
Mechanical axis of tibia?
Line drawn between the center of the knee and center of ankle mortise
Rosenberg view?
PA weight-bearing, knees at 45°
Complications of knee dx
Popliteal artery, stiffness
Schatzker classification
Tibial plateau fx I: lateral plateau split fx II: lat split/depression fx III: lat plateau depression IV: Medial plat. split fx V: Bicondylar plateau fx VI: Fx w/ metaphysial/diahyseal separation
What increases nonunion rate in tibial plateau fx?
Periosteal stripping
Associated injury in tibial plateau fx?
Meniscal (50%) and ligament (MCL>ACL) tears
5 P’s of compartment syndrome
Pallor Pulseless Pain (with passive stretch) Paralyzed Parasthesias
Maisonneuve fracture?
Complete syndesmosis disruption with diastasis and proximal fibula fx
Ruedi/Allgower classification
Pilon (distal tibial fx)
I) non/minimally displaced
II) displaced: articular surface incongruous
III) comminuted articular surface
Distal tibial fracture complications?
Posttraumatic DJD
Bundles of ACL
AM bundle - tight in flexion, loose in extension
PL bundle - Tight in extension, loose in flexion
Bundles of PCL
AL bundle - tight in flexion, loose in extension
PM bundle - tight in extension, loose in flexion
Ligament of Wrisberg
Posterior meniscofemoral ligament, Posterior to PCL, continuation of lateral meniscus
Popliteus insertion in relation to LCL origin
Anterior and distal
Insall ratio?
Patella [diagonal] length/patellar tendon length. >1.2= patella baja, >0.8= patella alta
Q angle?
Angle from ASIS to mid-patella to tibial tubercle. Nl male
Patella displacement test
Translate patella medially and laterally. Should translate 2 quadrants. Otherwise tight retinaculum.
Patella apprehension
Relax knee, push patella laterally. Pain/apprehension, patellar instability or MPFL injury
J sign
Actively extend knee from flexed position. Lateral displacement of patella in full extension=maltracking
Patella compression/grind
Extend knee, fire quads, compress patella. Pain=chondromalacia, OCD, PF arthritis, DJD
Joint line tenderness knee
Pain in joint line most sensitive test for meniscal tear
McMurray test
Flex/varus/ER knee, extend - medial meniscal tear
Flex/Valgus/IR knee, extend - lateral meniscal
Apley’s compression
Prone, knee 90°, compress and rotate. Pain or pop = meniscal tear
Lachman test
Flex knee 20-30°, anterior force on tibia. Laxity = ACL tear. Most sensitive ACL exam. Grade 1 0-5mm, grade 2 6-10mm, grade 3 >10mm. A=good endpoint, B= no endpoint
Anterior drawer test knee
Flex knee 90°, anterior force on tibia, laxity/anterior translation: ACL injury
Pivot shift knee
Supine, extend knee, IR, valgus force on proximal tibia, then flex knee. Clunk with knee flexion indicates ACL injury.
Posterior drawer test knee
Flex knee 90°, posterior force on tibia. Posterior translation: PCL injury
Posterior sag sig
Supine, hip 45°, knee 90°, view laterally. Posterior translation of tibia indicated PCL tear
Quadriceps active
Supine, flex 90°, fire quads. Posterior subluxed tibia translates anteriorly if PCL is deficient.
Reverse pivot shift
Supine, flex knee 45°, ER, valgus force on proximal tibia then extend knee. Clunk w/ extension indicated PCl injury
Valgus/varus stress
Lateral/medial force to knee at 30° and 0°. Laxity at 30° indicates LCL/MCL tear. Laxity at both indicates additonal cruciate ligament injury
Prone ER at 30 and 90° (dial)
Increased ER at 30°: PLC injury, at 90°, both PLC and PCL
ER recurvatum
Supine, legs straight, raise legs by toes, recurvatum, varus, and IR of knee indicates PLC (+/-PCL) injury
Slocum
Knee 90°, IR tibia 30°, anterior force - Displacement: anterior and lateral injury (ACL+PLC)
Knee 90·, ER tibia 30°, anterior force - Displacement: anterior and medial injury (ACL, MCL, POL)
PL drawer test
Knee 90°, ER tibia 15°, posterior force. Laxity indicates PLC and or PCL injury
PM drawer test
Knee 90°, IR tibia 30°, posterior force. Laxity indicates PCL and medial ligament (POL, MCL) injury.
Innervation of muscles in anterior compartment?
Deep peroneal (TA, EHL, EDL, peroneus T)
Innervation of muscles in lateral compartment?
Superficial peroneal (peroneus L and B)
Test L4 motor fxn with?
Dorsiflex
Test L5 motor fxn with?
Extend great toe
Test S1 motor fxn with?
Plantar flex foot
Innervation of superficial and deep posterior compartments of foot?
Tibial n
Acquired flat foot with injury of which muscle
Tibialis posterior
Which artery does the deep peroneal nerve run with
Anterior tibial a
What a supplies ACL and PCL?
Middle geniculate
Which artery does the tibial nerve run with?
Posterior tibial a
Most commonly affected compartment of the knee in OA?
Medial
Young female athlete with knee pain?
Think patellofemoral syndrome
Terrible triad knee
MCL, ACL, Medial meniscus
Segond fx? Association?
lateral tibial plateau bone avulsion, associated with ACL tear
Pelligrini-Steida?
Calcified medial epicondyle lesion
1 tumor in adolescents?
osteosarcoma
1 tumor in adults?
Chondrosarcoma
Blount’s disease
Genu varum, either infantile or adolescent.
Anterolateral bowing of tibia association
NF
Osgood-Schlatter disease
Traction apophysitis/osteochondrosis of the tibial tubercle
Tibial torsion
Congenital internal rotation of the tibia. Intoeing gait. Measure the transmalleolar axis IR/medial
Medial parapatellar approach to knee
IN planes?
Dangers?
Complication?
No IN plane
Infrapatella branch of saphenous nerve.
Complication= neuroma from cut nerve
Harmon approach
IN planes
Dangers
Posterolateral approach to knee
IN planes: Gastroc/soleus (tibial), peroneus longus/brevis (superficial peroneal)
Lesser saphenous vein, posterior tibial artery
Knee arthroscopy ports (6)
Anteromedial - watch anterior horn of medial meniscus
Anterolateral - anterior horn of lateral meniscus
Superolateral
Posteromedial - saphenous nerve
Posterolateral - peroneal nerve
Transpatellar - patellar tendon
