Download Anatomy and Biomechanics of the Knee

Anatomy and Biomechanics of the Knee Quiz
Bone Anatomy
1. The tibia has a _____________________ slope of ___________ degrees.
Anterior to Posterior, 7-10 degrees.
2. Matching
a. medial plateau
b. lateral plateau
_____smaller, more circular
_____concave in frontal plane
_____larger and biconcave
_____convex in sagittal plane
B, B, A,
3. What inserts on Gerdy’s tubercle? What is its precise location?
Gerdy’s tubercle is the insertion of the IT band and is located 2-3 cm lateral to the tibial
tubercle on the proximal tibia
4. Matching
a. Medial Femoral Condyle
b. Lateral Femoral Condyle
_____projects further anteriorly
_____projects more distally
_____projects more posteriorly
_____more width in medial-lateral direction
_____larger condyle
B, A, A, B, A
5. What is the sulcus terminalis?
The sulcus terminalis is a small ridge just distal to the intercondylar notch of the LFC.
6. T/F. The patella has the thinnest articular surface in the body
False
7. Name the arteries and their corresponding branches that form the anastomosis that
supplies blood to the knee.
The femoral artery gives off the descending geniculate artery. The popliteal artery
supplies the medial/lateral superior and inferior geniculate arteries and the middle
geniculate artery. The anterior tibial recurrent artery also supplies the knee.
8. Describe the blood supply of the patella.
Derived from the geniculate artery complex and the anterior tibial recurrent artery. The
blood supply primarily comes in the mid- to inferior portion of the patella.
9. What major nerves innervate the knee?
Branches from the femoral, obturator, and sciatic nerve.
10. What is the largest nerve that provides innervation to the intra-articular portion of the
knee? What structures does it supply?
The posterior articular branch of the posterior tibial nerve supplies the infrapatellar fat
pad, the synovium of the ACL and PCL and the periphery of the meniscus.
11. What is the average length and width of the ACL?
Length is 33mm; width is 11mm
12. What is the predominate blood supply to the ACL?
The middle geniculate artery.
13. Where are the ACL femoral/tibial attachments?
The femoral attachment is a semicircular area on the posteromedial aspect of the LFC
(20mm long and 10mm wide). The tibial attachment is a broad, irregular, oval-shaped
area just slightly medial and anterior to the midline between the tibial eminences.
14. What is the average length and width of the PCL?
Length is 38mm; width is 13mm
15. What are the meniscofemoral ligaments? Name the origins and insertions?
The meniscofemoral ligaments are the ligaments of Humphrey and Wrisberg. They
originate from the posterior horn of the lateral meniscus and insert into the substance of
the PCL and MFC.
16. T/F. The PCL has a more abundant blood supply than the ACL
True
17. The anterior fibers of the superficial MCL tighten during what knee ROM? The
posterior fibers…?
The anterior fibers tighten during the first 90 degrees of flexion. The posterior fibers
tighten in extension.
18. The deep layer of the MCL is intimately associated with the medial meniscus by
attachments by the?
Coronary ligaments
19. The blood supply to the MCL is?
The superomedial and inferomedial geniculate arteries.
20. Name the contents of the Posteromedial corner of the knee.
The various insertions of the semimembranosus tendon, oblique popliteal ligament and
the posterior oblique ligament make up the PM corner.
21. Describe the layers of the medial side of the knee from superficial to deep.
Layer I- deep fascia overlying the vastus medialis and MCL, extending to the Sartorius
Layer II- superficial MCL and the posterior oblique ligament
Layer III- joint capsule, deep MCL, and the coronary ligaments
The semitendinosus and gracilis tendons are located between layer I and II.
22. The LCL is located ______________ and _____________ to the insertion of the
popliteus tendon on the LFC
Posterior and superior
23. What are the layers and their corresponding contents of the Posterolateral Corner of
the knee?
Superficial- biceps femoris tendon and the IT band
Deep- LCL, capsule, popliteus, arcuate ligament, popliteofibular ligament, and the
fabellofibular ligament
24. What is a Segond fracture?
An avulsion of the meniscotibial component of the mid-third lateral knee capsule.
Pathognomic for an ACL injury.
25. What are the popliteomeniscal fascicles?
The popliteus, as it courses intra-articularly, gives off three branches that contribute to
the dynamic stability of the lateral meniscus.
26. What is the key restraint in preventing lateral displacement of the patella?
The medial patellofemoral ligament which originates from the adductor tubercle and
inserts onto the medial border of the patella
27. What is the width of the patellar tendon?
30-35mm
28. What are the boundaries of the popliteal fossa?
The biceps femoris forms the lateral proximal border; the semimembranosus and pes
anserinus forms the medial proximal border. The two heads of the gastroc form the
boundaries distally.
29. What is the blood supply of the menisci? What percentages of width is the vascular
penetration?
The main blood supply is from the lateral and medial geniculate arteries. The medial
meniscus’ vascularity is 20-30% of its width, while the lateral meniscus has its peripheral
10-25% supplied.
30. What is the primary composition of the menisci and in what directions do their fibers
run?
The menisci are primarily type I collagen and the fibers run obliquely, radially, and
vertically.
31. The menisci are connected anteriorly by the ____________ and peripherally by the
_____________.
Transverse (intermeniscal) ligament / coronary ligaments
32. Matching
a. Medial meniscus
b. Lateral meniscus
____circular, covers more articular surface
____average thickness of 3-5 mm
____average thickness of 4-5 mm
____C-shaped
____average width of 9-10 mm
____average width of 10-12 mm
B, A, B, A, A, B
33. Describe what occurs during gait in patients with ACL-deficient knees?
Patients with ACL deficient knees demonstrate the avoidance of quadriceps contraction
during activities when the knee is near full extension. This interferes with limb
advancement because the knee is flexed and the limb does not easily reach the ground. It
also results in increased contralateral hip and knee flexion so that there is limb clearance
during swing phase.
34. T/F. The mean maximum forces on the ligaments of the knee during walking are
greatest in the PCL.
True. 329N
35. T/F. Peak tibiofemoral compressive forces occur during squats.
False. Peak forces across the tibiofemoral joint occur during knee extension. 3285N
36. T/F. Peak tension in the PCL occur during squats and leg presses.
True. 1868N and 1866N
37. During leg presses and squats there is ________ anterior ACL tension. ________
ACL tension is 142N during seated knee flexion.
No; greatest
38. During isokinetic and isometric extension, peak ACL forces occur at knee angles of
____ to ____ degrees while peak PCL forces are _______ (higher/lower) and occur at
_______ degrees.
35-40 degrees; lower at 90 degrees
39. What are the bundles of the ACL? In what position are the bundles tightest?
The AM bundle is tight in flexion. The PL bundle is tight in extension.
40. What is the ultimate tensile load of the ACL?
2000N
41. What are the bundles of the PCL?
AL and PM bundles
42. Matching
a. ACL
b. PCL
c. MCL
d. LCL/PLC
e. MM
____ primary restraint to varus angulation
____ primary restraint to valgus angulation
____ primary restraint to posterior tibial translation
____ primary restraint to anterior tibial translation
____ secondary restraint to varus and valgus angulation
____ secondary restraint to anterior and posterior tibial translation
____ secondary restraint to external rotation
____ secondary restraint to anterior tibial translation in ACLdeficient knee
D, C, B, A, B, C, D, E
43. Total menisectomy results in a ____ to ____ % increase in mean peak articular
cartilage contact pressures.
200-300%
44. Matching
a. Lachman test
b. Anterior drawer
c. Posterior drawer
____most accurate test for diagnosing PCL injuries
____high false-negative rate for diagnosing ACL injuries
____most sensitive test for diagnosing ACL injuries
____gives step-off between MTP and MFC in PCL injuries
C, B, A, C
45. Varus and Valgus stress testing at 0 and 30 degrees:
Isolated collateral ligament injuries will have _________________
High-grade collateral ligament injuries will have ______________ and are
usually combined with ______ and ______ injuries.
Increased laxity at 30 degrees only
Increased laxity at 30 and 0 degrees; ACL and PCL
46. Describe the dial test.
The dial test is used to differentiate between PCL and PL corner injuries. It can be
performed supine or prone. The tibia is passively externally rotated on the femur.
Increased external rotation at 30 degrees but not at 90 degrees is indicative of an isolated
PL corner injury. Increases at both 30 and 90 degrees suggest injury to both the PL
corner and the PCL. A side-to-side difference of greater than 10 degrees constitutes a
positive test.
47. Describe the Pivot-shift test
The pivot-shift test aids in diagnosing ACL injury. A combination of valgus stress,
internal rotation, and axial loading is applied to the proximal tibia as the knee is taken
from a position of extension to flexion. With the knee in extension, the lateral tibial
plateau is subluxated in the ACL-deficient knee. A positive test is appreciated by a
“clunk” when reduction of the tibia occurs on the femur at approximately 30 degrees of
knee flexion. A positive test correlates well with patient symptoms of “giving way.”
48. Matching
A.
B.
C.
D.
E.
F.
G.
H.
Medial plateau
Lateral plateau
PCL
Posterior horn medial meniscus
Posterior horn lateral meniscus
ACL
Anterior horn lateral meniscus
Anterior horn medial meniscus