Knee Flashcards
Which condyle of the femur is larger to compensate for the alignment of the knee?
Medial - lateral more directly aligned with shaft
Which condyle has a larger interface with the tibia?
Medial
Define the sulcus angle:
Angle between highest points of the condyles and lowest point of intercondylar sulcus
What is the average sulcus angle?
138 +/- 6
Is a shallow sulcus angle larger or smaller?
Larger - flat like straight line
What does the congruence angle reflect?
Patellar position in trochlear groove
What is normal for the knee, medial or lateral tilt? and is the congruence angle positive or negative?
Medial tilt is normal - negative value
What congruence angle is associated with patellar subluxation?
+ 16 indicative of lateral tilt
What alignment is normal for knees, valgus or varus?
Valgus - angle >185 deg
What is considered more varus type alignment?
Angle of < 175 deg
What shape is the medial meniscus?
C
What shape is the lateral meniscus?
O
What third of the meniscus gets blood supply from the capsular arteries?
Peripheral third (red-red zone)
What zone is the white-white zone and has very little blood flow?
Central aspect of the meniscus
What unique area of the lateral meniscus is separated from the capsule by the popliteus and as a result is relatively avascular?
Posterior lateral corner
What are the functions (4) of the meniscus?
1) inc contact area of the joint
2) assist with gliding
3) limit hyperextension
4) provide cushion/support
Are mensici innervated?
Yes - two types; pain receptors, joint mechanoreceptors -> affects proprioception
What ligament fixes the meniscus to the edge of the joint capsule?
Coronary ligament
What ligament joints the two menisci together anteriorly?
Transverse ligament
What ligament attaches the mensici to the patella?
Patellomeniscal ligament - thickening of anterior capsule
What muscle can create motion in the lateral meniscus?
Popliteus
Does the lateral mensicus attach to any other ligamentous structures?
PCL
What muscle has a posterior attachment to the medial meniscus?
Semimembranosus
Does the medial meniscus attach to any other ligamentous structures?
ACL (anterior horn) and PCL (posterior horn)
Which meniscus is less mobile?
Medial = higher incidence of injury
What muscle creates movement for the medial mensicus?
Semimembranosus
The posterior lateral compartment is supported by what complex?
Arcuate complex (LCL, arcuate ligament and popliteus)
What muscles reinforce the arcuate complex?
Biceps femoris, popliteus, lateral gastroc head
What is the name of the sesamoid bone found in the LCL that is in 15-30% of people?
Fabella - attaches by fabellofibular ligament
The LCL shares a common insertion with what muscle on which bony landmark?
Biceps femoris on the fibular head
Is the LCL intra or extracapsular?
Extra
What ligament in the posterior medial compartment provides resistance to valgus at near full extension?
Posterior oblique ligament, which is a thickening of the medial caspular ligament
What ligament is an expansion of the tendon sheath of the semimembranosus, which inserts across the joint into the proximal lateral gastroc head?
Oblique popliteal ligament
MCL has two layers; superficial and deep - which layer restricts vaglus, which restricts anterior translation and supports the medial meniscus?
Superficial primarily restrains valgus
Deep provides mensical support and probably restrains anterior translation
Does the MCL or LCL have a rich blood supply?
MCL - up to grade 2+ will heal under proper conditions
Which other major ligament plays a secondary role in valgus restriction?
PCL
Which ligament is a thick medial expansion of the medial retinaculum?
Medial patellofemoral ligament
Where does the medial patellofemoral ligament insert?
With the VMO on the patella
What ligament is an expansion of the ITB?
Lateral patellofemoral ligament
What artery is the blood supply for the cruciate ligaments?
Genicular artery
What nerve innervates the cruciate ligaments?
Tibial nerve
Do the cruciate ligaments have mechanoreceptors?
Yes - Ruffini corpuscles, Pacinian corpuscles, Golgi tendon organs
What motions does the ACL provide stabilization against?
Hyperextension (femur on grounded tibia - tibia on open chain femur) as well as IR
ACL has two bundles: what motions are the small and large bundles taut in?
Small: (anterior medial) taut in flexion from 20-90 deg, limiting anterior translation
Large (posterior lateral) taut in extension - largest restraint until 20 deg of flexion
What is the PCL’s primary restraint motion?
Posterior displacement (esp between 30-90 deg of flexion)
In what arc of flexion does the greatest posterior translation occur?
Between 70-90 deg of flexion - PCL is most taut is inflexion esp the large anterolateral bundle
What percentage of the PCL makes up the small posteromedial bundle and where is it taut?
5% and it’s taut in extension
What motions do both the ACL and PCL provide secondary assistance with restricting?
Valgus and varus forces
What are the IRs of the knee?
Popliteus, gracilis, sartorius, semimembranosus, semitendinosus
What are the ERs of the knee?
Biceps femoris, TFL
What four muscles make up the insertion for pes anserine?
Sartorius, gracilis, semimembranosus, semitendinosus
What 3 muscles place a valgus force on the knee?
Biceps femoris, lateral gastroc head, popliteus
What 5 muscles place a varus force on the knee?
Semimembranosus, semitendinosus, medial head gastroc, sartorius, gracilis
During knee flexion, what are the arthrokinematics of the knee?
Posterior glide of tibia on femur (open chain) / posterior roll with anterior glide (closed chain)
During knee extension, what are the arthorkinematics of the knee?
Anterior glide of tibia on femur (open chain) / anterior roll with posterior glide (closed chain)
What direction in rotation does terminal knee extension include?
Lateral or external rotation -> screw home mechanism
What direction direction in rotation does the knee unlock into?
Medial or internal rotation
Where is the odd facet located?
On the extreme medial aspect of the medial facet
When does the odd facet contact the trochlea?
During deep knee flexion > 135 deg
During flexion ROM, when does the patella initially contact the trochlear groove?
20 deg of flexion
During manual therapy, what directions are combined to improve PFJ mobility due to tilting and rotation?
Superior lateral
Inferior medial
What are plicae?
Synovial membrane folds
What area of the knee are plica most commonly irritated
Medially
What area of the knee are plica least commonly located?
Laterally
What compresses the patella more, flexion or extension?
Flexion - during deep flexion; odd and lateral facets engage to decrease contact pressure
What are the compressive forces associated with:
Standing from a chair
Walking
Running/jogging
Chair - 6.7 x
Walking - 2x
Jogging - 3-4x
During deeper flexion, what function does the quadriceps tendon serve regarding dissipating forces?
Makes greater contact in trochlear groove beyond 90 deg to dec forces
When the subjective complaints are of PFJ, what ROM of flexion is safe to avoid compressive forces?
30-90 deg - lack of compressive/contact forces
What are 3 anatomical reasons for PFJ instability?
1) shallow trochlear groove
2) lateral femoral condyle less prominent
3) soft tethers of PFJ lax
What are the two ligamentous tethers for the PFJ?
Medial patellofemoral ligament vs lateral patellofemoral ligament
What is the open pack position for the knee?
Extension
Define the Q-angle:
Angle between ASIS to patellar midpoint to tibial tuberosity
What are normal Q-angles for men vs women?
Men 10-15
Women 15-20
What Q-angle tends to be associated with lateral subluxation?
> 20 deg
What are the 5 component parts of the Ottawa Knee Rules?
1) age >55
2) isolated tenderness of patella
3) tenderness at fibular head
4) inability to flex knee to 90 deg
5) inability to bear weight
What 3 additional components were added to the Ottawa ankle rules (Pittsburgh Rules)?
1) blunt trauma/fall
2) under 12 over 50 years
3) unable to walk 4 WB steps
What diagnosis should be considered with anterior knee pain with a negative knee exam, with excessive ER of the hip, with loss of IR of the hip?
SCFE - slipped capital femoral epiphysis
What diagnosis should be considered with pain in the hip and/or knee, with a negative knee exam and found in active adolescents (5-12 y.o.s)?
Legg-Calve-Perthes syndrome
What outcome measure is directed at knee OA and/or TKA?
WOMAC - looks at pain, stiffness and function
Western Ontario and McMaster Universities OA index
What index as an extension of the WOMAC, looks at person’s with OA with higher levels of activity?
KOOS - knee injury and OA outcome score
What is the MDC and MCID for the Knee Outcome Score?
MDC 9
MCID 7
What outcome measure has been adapted to long term outcomes for ACLRs?
Tampa Kinesiophobia Scale - TKS
Describe the grades for effusion:
0: none
Trace: medial sweep, lateral small amt return
1+: milk out, does not return on own but does with lateral sweep
2+: milk swelling and returns immediately
3+: cannot milk the swelling out
What tool can augment MMT measurements due to standardized positions with readings?
Dynamometer - but can be dependent on strength of examiner
In ligamentous assessment: what are the grading systems for joint laxity?
1+: 3-5 mm
2+: 5-10 mm
3+: 10+ mm
How many deg of flexion are the MCL and LCL tested at?
30 deg of flexion
What structures may be affected with positive varus testing at 0 deg/neutral?
ACL, PCL, LCL
What bundle is the anterior drawer test assessing of the ACL?
Anteromedial
What degree of motion is considered a positive test for the anterior drawer?
> 6 mm with empty/soft endfeel
When testing the anterior drawer with excess ER, what area of the knee is being assessed?
Anterolateral instability
What has greater sensitivity/specificity for ACL assessment - Lachman’s or Anterior drawer?
Lachman’s
What bundle does Lachman’s assess with the ACL?
Posterolateral
Does the pivot shift test have a high specificity or sensitivity?
High specificity
Does the pivot shift test require IR or ER of the knee?
30 deg of hip flexion/abduction, knee in extension with valgus force at fibula, knee IR -> tibial subluxation at 30-40 deg of flexion
What muscle is isometrically activated to assess for posterior sag?
90 deg of knee flexion -> activate QUAD and see if tibial anterior reduction
What motion is added to the posterior drawer to assess the posterolateral corner?
ER
What 4 structures make of the posterolateral corner?
1) LCL
2) arcuate ligament
3) popliteal tendon
4) lateral head of the gastroc
When performing posterior drawer test: 1) what two positions is the test conducted 2) what are implications of positive testing at each location
30 and 90 deg of flexion
If increased at 30 deg, compared to 90 deg -> posterolateral corner injury
What two degrees of flexion are the Dial test performed at? What direction of rotation is the tibia rotated?
30 and 90 degrees - ER
If increased at 30 deg, compared to 90 deg -> posterolateral corner injury
If excessive at both -> PCL
Positive test = 10 deg or greater
What applications of force on the knee are provided during the Reverse pivot shift test?
Knee flexed 70-80 deg, valgus force at proximal fibula, with ER of tibia and moving into extension with axial load
During McMurray’s test - which rotational application will provoke the medial and lateral aspects of the meniscus?
Medial/IR will affect lateral meniscus
Lateral/ER will affect medial meniscus
Is joint line assessment for mensical pathology more sensitive or specific?
Screening tool -> sensitive
Which degree of flexion is the Thessaly test more sensitive, specific and have a greater positive predictive value?
20 degrees
What are the five items which have a large positive predictive value indicating meniscal pathology?
1) hx of catch/locking
2) joint line tenderness
3) pain with forced hyperextension
4) pain with maximal passive knee flexion
5) pain/audible click with McMurrays
3 = 75% ppv, 5 =92%
Define the Sage sign:
Greater than 25-50% displacement of patella in PFJ
What is a positive test for Apprehension with PFJ testing?
Expression of apprehension when trying to manually sublux the patella at 20-30 deg of flexion
What is a positive patellar tilt test?
Normally can flip patella laterally over horizontal - positive test is tight retinaculum and unable to do so
Cook cluster testing for PFJ pain (6 items):
1) manual compression of PFJ
2) pain during palpation of posteromedial/lateral borders of patella
3) pain during squat
4) pain while kneeling
5) pain with resisted quad testing
6) pain with prolong sitting
There is no gold standard for return to sport, but what assessments are commonly used?
Hop testing: single, triple, cross over triple, timed 6 meter test - 80-85% of uninvolved leg
Which two hop tests are considered strongest predictors per self-reported function comparison?
Cross over hop, 6-m timed test
Which direction during Y-balance/Star excursion testing has a 2.5x greater risk of injury?
Anteriorly with >4 cm difference
What are optimal ratios for hamstring/quad strength for males/females respectively for return to sport?
> 66% males, >75% females
What muscle is keenly focused to strengthen post-operative ACL?
Quadriceps - even with use of HS graft
What dictates post-surgical protocol in ACL and meniscal/cartilage injury?
Meniscal or cartilage restrictions
When undergoing both ACL and PCL repair, which dictates protocol?
PCL
Is surgical approach same for skeletally immature person versus adult?
No - consideration for physis/growth plate as well as different fixations used
What reasons are found that females are 4.8x more likely to tear their ACLs?
1) less absorptive landing pattern
2) muscle weakness
3) excessive quad activation
4) inc joint laxity
5) more narrow femoral notch
6) hormonal influences
7) wider pelvis -> genu valgum
Where is graft site for PCL?
Achilles - replicates anterolateral bundle
What ROM is often limited for at least 2 if not 4 weeks with PCL repair?
70-90 deg of flexion due to maximal tension placed on PCL
Can NWB resisted knee extension 70-90 deg place stress on the PCL?
Yes - maximal tension between 85-95 deg NWB
Does a posterior corner injury typically occur in isolation?
No - concurrent PCL injury
What are the primary stabilizers for the posterior corner?
Popliteus tendon, popliteofibular ligament, LCL
What are the secondary stabilizers for the posterior corner?
Arcuate ligament, posterolateral capsule, coronary ligament, oblique popliteal ligament
Meniscal tears in what area of the knee tend to be repaired due to blood flow?
Peripheral third - red/red zone
Middle third - red/white zone
Inner third - white/white zone
What is the single strongest predictor of function in those with OA and chondral damage?
Quad weakness
What is looked at as predictor of functional ability one year after TKA?
Preoperative quad strength
When does most pain relief occur with hyaluronic acid joint injections?
2-3 months after completion of series
What version of glucosamine oral supplementation has some positive benefits for OA?
Glucosamine sulfate with chondroitin
What amount of weight lost results in moderate improvement in pain and function in OA (meta-analysis)?
13.5#
What is the surgical option for medial compartment degeneration?
High tibial osteotomy
What is the surgical option for lateral compartment degeneration?
Femoral osteotomy
What has higher failure rate, unicompartmental UKA or TKA?
UKA
Which surgical option results in greater ROM and return to function more quickly? (TKA vs UKA)
UKA
Which version of the TKA has progressive WB over the first 6 weeks? (Cemented vs. non-cemented)
Non-cemented - AD with WB restriction
In performing manual therapy for TKA, is there value for PFJ or tibiofemoral joint mobilizations?
PFJ - unsure of benefit of tibiofemoral mobs
In regard of use of NMES, is early or late initiation more beneficial?
Early
What impacts wound healing in TKA?
DM, RA, obesity, steroids
Does stiffness preoperatively correlate with stiffness post-operatively?
Yes - as well as deg of OA, poor physical health (obese, DM)
In articular cartilage injury, what three methods stimulate bleeding to create a clot and stem cells to grow fibrocartilage?
Debridement, chondroplasty, microfracture
Which is the three surgical options for cartilage repair has restrictions for WBing?
Microfracture - can WB right away with debridement and chondroplasty
In both OATs (osteochondral autograft transplant) and ACI (autologous chondrocyte implantation), what is a huge indicator in progressing WB exercise?
Edema in the joint - reassessed before progression
What are six loosely associated groups of PFPS? (factors contributing)
1) hip abductor weakness
2) quad weakness
3) patellar hypomobility
4) patellar hypomobility
5) pronated foot posture
6) lower limb biarticular muscle tightness (quads/hams)
In those with a subluxation hx for PFPS, what ROM is most comfortable and safe due to seeding in the PFJ?
70-90 deg of flexion
What two surgical approaches are used to reduce number of dislocations in PF subluxors?
1) medialization of tibial tubercle: medialized and elevated to realign tibial tubercle in more anatomical position
2) lateral release with/without medial patellar ligament repair
What is bipartite patella?
A congenital anomaly that may become apparent when patella sustains direct trauma creating instability between two fragments - may need surgical fixation
Define Osgood-Schlatter disease:
Inflammation (apophysitis) of patellar tendon on tibial tubercle
Define Sinding Larson Johasson (SLJ) syndrome:
Inflammation (apophysitis) of patellar tendon at inferior pole of patella
In sport-specialized versus multi-sport athletes, what diagnoses are 4x more common?
Apophyseal injuries - Osgood & Sinding Larson Johasson
