1
Q
What are the three articulations forming the knee joint?
A
2 femorotibial and 1 femoropatellar
2
Q
Which muscle laterally rotates the femur to allow flexion of the knee from full extension?
A
Popliteus
3
Q
Which of the knee bursae is the largest and is also continuous with the synovial cavity of the knee joint?
A
Suprapatellar bursa
4
Q
What are the inferior borders of the popliteal fossa?
A
Medial and lateral head of gastrocnemius (and plantaris)
5
Q
Which muscle crosses both the knee joint and ankle joints and flexes the leg at the knee?
A
Gastrocnemius
6
Q
Which nerve passes in close proximity to the neck of the fibula, heading to the lateral compartment of the leg?
A
Common fibular nerve
7
Q
Where do quadriceps muscles insert distally?
A
Tibial tuberosity
8
Q
Which knee ligament prevents anterior displacement of the tibia on the femur?
A
Anterior cruciate ligament
9
Q
What opening does the femoral artery pass through to get to the popliteal fossa and which muscle tendon forms this opening?
A
Adductor hiatus and adductor magnus
10
Q
What does the term Genu Valgum (knock knee) refer to?
A
Angle between longitudinal axes of bones greater than 17 degrees (tibia abducted with respect to femur)
11
Q
List the main components of the knee region.
A
- condyles of distal femur and proximal tibia
- head of the fibula
- patella
- popliteal fossa
- 2 femorotibial articulations
- 1 femoropatellar articulation
12
Q
What is the longest and heaviest bone in the body?
A
Femur
13
Q
What is the function of the femur?
A
Transmits body weight from hip bone to the tibia when a person is standing, and is an important attactment site for many muscles and ligaments.
14
Q
Describe the proximal aspect of the femur.
A
- consists of a head, neck and 2 trochanters
15
Q
Describe the head of the femur.
A
- found at proximal aspect
- articulates with acetabelum of pelvis to form hip joint
- smooth surfave covered with articular cartilage
- small depression not covered in articular cartilage = fovea where ligamentum teres attaches
16
Q
Describe the neck of the femur.
A
- connects head of the femur with the shaft
- cylindical, projecting superiorly and medially
- angle of inclination = approx 126 degrees
- this angle allows for increased range of movement at hip joint
17
Q
Why is the angle of inclination typically less in females?
A
Due to wider pelvis
18
Q
Describe the greater trochanter of the femur.
A
- most lateral, palpable projection of the bone
- attachment site for gluteus medius, gluteus minimus and piriformis
- origin site of vastus lateralis
19
Q
Describe the lesser trochanter of the femur.
A
- projects from posteromedial side of femur
- attachment site for iliopsoas
20
Q
What is the angle of inclination in the femur?
A
The angle resulting from the intersection of a line down the long shaft of the femur and a line drawn through the neck of the femur. Approx 126 degrees.
21
Q
Describe the intertrochanteric line of the femur.
A
- a ridge of bone that runs in an inferomedial direction on the anterior surface of the femur
- spans between greater and lesser trochanter
- after passing lesser trochanter on posterior surface it becomes the pectineal line
- attachment site for iliofemoral ligament
- anterior attachment of hip joint capsule
22
Q
Describe the intertrochanteric crest of the femur.
A
- ridge of bone that connets the greater and lesser trochanters on posterior aspect of femur
- contains rounded tuberble on superior half called the quadrate tubercle
- quadratus femoris attaches to quadrate tubercle
23
Q
Describe the shaft of the femur.
A
- descends in a slight medial direction to bring knees closer to body’s centre of gravity thus increasing stability
- posterior surface contains roughened ridges of bone called linea aspera
- linea aspera splits distally to form medial and lateral supracondylar lines - flat popliteal surface lies between these
- proximally, medial border of linea aspera becomes the pectineal line and lateral border becomes the gluteal tuberosity where gluteus maximus attaches
- distally, linea aspera widens and forms floor of popliteal fossa
- medial supracondylar line ends at the adductor tubercle, where adductor magnus attaches
24
Q
Describe the medial and lateral condyles of the distal end of the femur.
A
- posterior and inferior surfaces articulate with tibia and menisci of the knee
- anterior surface articulates with patella
25
Describe the medial and lateral epicondlyes of the distal end of the femur.
- bony elevations on the non-articular area of the condyles
- medial epicondyle is larger
- medial and lateral collateral ligaments of the knee originate from respective epicondyles
26
Describe the intercondylar fossa of the distal end of the femur.
- a deep notch on the posterior surface of the femur between the 2 condyles
- contains factes for attachment of anterior cruciate ligament and posterior cruciate ligament
27
What type of bone is the patella and what is it attached to?
- largest sesamoid bone of the body
- superior aspect attached to the quadriceps tendon
- inferior aspect attacked to the patellar ligament
28
Describe the bony landmarks of the patella.
- apex situated inferiorly and connected to tibial tuberosity by the patellar ligament
- base forms the superior aspect and serves as attachment site for the quadriceps tendon
- posterior surfce of patella articulates with the femur and has medial and lateral facets
- medial facet articulates with medial condyle of the femur
- lateral facet articulates with the lateral condyle of the femur
29
What are the functions of the patella?
- leg extension
| - protection
30
What is the second largest bone in the body?
The tibia
31
Describe the proximal end of the tibia.
- widened by medial and lateral condyles which aid in weight bearing
- condyles form a flat surface known as the tibial plateau
- tibial plateau articulates with femoral condyles to form key articulation of knee joint
- intercondylar eminence located between condyles and projects upwards as medial and lateral intercondylar tubercles
- intercondylar eminence is main attachment site for ligaments and menisci of the knee joint
- intercondylar tubercles articulate with intercondylar fossa of the femur
32
Describe the shaft of the tibia.
- prism shaped with 3 borders and 3 surfaces - anterior, posterior and lateral
- anterior border palpable as the shin, contains tibial tuberosity at proximal end, the attachment site for the patellar ligament
- posterior surface marked by a ridge of bone known as the soleal line (site of origin for soleus muscle)
- lateral border also known as interosseous border and gives attachment to interosseous membrane that binds the tibia and fibula together
33
Describe the distal end of the tibia.
- widens to assist with weight bearing
- medial malleolus is a bony projection continuing inferiorly on the medial aspect of the tibia and articulates with tarsal bones to form ankle joint
- fibular notch located laterally where the fibula is connected to tibia creating the distal tibiofibular joint
- tendon of tibialis posterior passes through a groove on posterior surface
34
What is the main function the fibula?
To act as attachment site for muscles rather than weight bearing
35
What are the three main articulations of the fibula?
- proximal tibiofibular joint
- distal tibiofibular joint
- ankle joint
36
Describe the proximal end of the fibula.
- not part of knee joint
- has an enlarged head which contains a facet for articulation with lateral condyle of the tibia
- common fibular nerve can be found on posterior and lateral surface of fibular neck
37
Describe the shaft of the fibula.
- has 3 surfaces - anterior, lateral and posterior
| - each surface faces respective compartment of leg
38
Describe the distal end of the fibula
- lateral surface continues inferiorly and is called the lateral malleolus
- lateral malleolus more prominent than medial malleolus and can be palpated at the ankel on lateral side of leg
39
Describe the knee joint.
- hinge synovial joint
- mainly allows for flexion and extension
- small degree of meial and lateral rotation
- formed by articulations between patella, femur and tibia
40
What is the Q angle?
- the angle between femur and tibia (approx 15 degrees)
- can be measured by drawing a line from the anterior superior iliac spine (ASIS) to the middle of the patella and another line through the patella and tibial tuberosity
- allows the knee to be positioned under hip and distributes weight evenly across knee
41
Why is the Q angle usually greater in females?
Due to wider pelvis
42
Describe genu varum/bow leg.
- angle between longitudinal axes bones less than 17 degrees
- tibia adducted with respect to femur
- may be a sign of Blount’s disease or rickets
- could lead to osteoarthritis in knees
43
Describe genu valgum/knock knees.
- angle between longitudinal axes of bones greater than 17 degrees
- tibia abducted with respect to femur
- could cause osteoarthritis
44
When is the knee joint most stable?
In the extended position as the articular surfaces are most congruent during extension.
45
What kind of cartilage lines the joint surfaces of the knee?
Hyaline
46
Describe the 3 articulations of the knee joint.
- 2 femorotibial: lateral and medial between condyles of femur and tibia
- femoropatellar: anterior aspect of distal femur articulates with the patella
47
Describe the relevance of the patella being formed and residing within the quadriceps femoris tendon.
It provides a fulcrum to increase power of the knee extensor and serves as a stabilising structure that reduces friction forces placed on femoral condyles.
48
What movements occur at the knee joint?
- mainly flexion and extension
| - some medial and lateral rotation
49
Describe extension at the knee.
- normal knees extend to 0 degrees
- primary muscle involved is quadriceps femoris
- secondary muscle involved is tensor fasciae latae
50
Describe flexion at the knee.
- 120 degrees when hip is extended; 140 degrees when hip is flexed; 160 degrees passively
- primary muscles involved: hamstrings (semitendinoses, semimembranosus, long head of biceps) and short head of biceps
- secondary musces involved: gracilis, sartorius, gastrocnemius and popliteus
51
Describe medial rotation at the knee.
- 10 degrees with knee flexed; 5 degrees with knee extended
- primary muscles involved are semitendinosus and semimembranosus when knee is flexed; popliteus when nonbearing knee is extended
- secondary muscles involved are gracilis and sartorius
52
Describe lateral rotation at the knee.
- 30-40 degrees when knee is flexed to 90 degrees
| - primary muscle involved is biceps femors when knee is flexed
53
Descibe the ‘locking’ of the knee.
As the joint approaches full extension, the femur undergoes a few degrees of medial rotation on the tibia and this is known as ‘locking’ the knee. This position makes the lower limb a solid column and more adapted for weight bearing. During the ‘lock’ the thigh muscles are relaxed.
54
Describe ‘unlocking’ of the knee.
The knee is unlocked when the popliteus muscle contracts, thus laterally rotating the femur about 5 degrees on the tibial plateua so that flexion of the knee can occur.
55
Describe the joint capsule of the knee.
- thin and incomplete
- replaced anteriorly by quadriceps tendon, patella and patellar tendon (ligament)
- has a gap posteriorly to allow popliteus muscle to exit the joint
- external fibrous layer and internal synovial membrane
56
State how many bursae are found at the knee joint and list the 4 main bursae.
- at least 12
- prepatellar
- infrapatellar (deep and superficial)
- suprapatellar
57
Describe the suprapatellar bursa of the knee.
- an extension of the synovial cavity of the knee
- the largest bursa of the knee
- located between quadriceps femoris and the femur
- held in place by articularis genus muscle (part of vastus intermedius)
58
Describe the infrapatellar (deep and superficial) bursae of the knee.
- deep lies between tibia and the patella ligament
| - superficial lies between patella ligament and the skin
59
Describe the prepatellar bursa of the knee.
- found between the apex of the patella and the skin
60
Which muscles are the main stabilisers of the knee?
Quadriceps, hamstrings, sartorius, gracilis and iliotibial tract.
61
How might surgery be avoided when a knee ligament is damaged?
By using physiotherapy to build up quadriceps as this is such an important stabiliser of the knee that if adequately strengthened it could compensate for the damaged ligament and thus prevent the need for surgery.
62
List the ligaments of the knee joint.
- patellar ligament
- tibial/medial collateral ligament
- fibular/lateral collateral ligament
- anterior cruciate ligament
- posterior cruciate ligament
63
Describe the patellar ligament.
A continuation of the quadriceps femoris tendon distal to the patella. It attaches to the tibial tuberosity.
64
Describe the medial/tibial collateral ligament.
- flat band attached to the medial meniscus
- attaches proximally to medial epicondyle of the femur and distally to medial condyle of the tibia
- prevents abduction of the leg at the knee
- prevents rotation during extension of the knee to contribute to stability while standing
65
Describe the lateral/fibular collateral ligament.
- cord like band NOT attached to the lateral meniscus
- attaches proximally to lateral epicondyle of femur and distally to a depression on the lateral surface of the fibular head
- prevents adduction of the leg at the knee
- prevents rotation during extenion of the knee, contributing to stability whilst standing
66
Describe the anterior cruciate ligament.
- weaker than the posterior cruciate ligament, more likely to be injured
- attaches to anterior intercondylar region of the tibia and travels superoposteriorly to attach to the lateral femoral condyle
67
What is the function of the anterior cruciate ligament?
- prevents anterior displacement of the tibia on the femur
| - prevents hyperextension
68
Describe the posterior cruciate ligament.
- attaches to the posterior intercondylar region of the tibia and travels superoanteriorly to insert onto the medial femoral condyle
69
What is the function of the posterior cruciate ligament?
- prevents posterior displacement of the tibia on the femur
- prevents hyperflexion of the knee
- main stabiliser of the knee when weight bearing e.g. walking down a hill
70
When would damage to the ACL occur and what test is used to assess any damage?
- damage occurs when knee is hyperextended or force is applied anteriorly (e.g. tackling in football)
- use anterior drawer sign to assess damage - tibia will be pulled anteriorly indicating damage to ACL
71
When would damage to the PCL occur and what test can be used to assess the damage?
- damage can occur when landing on the tibial tuberosity with the knee flexed
- posterior drawer sign used to assess - tibia will be pushed posteriorly indicating damage to PCL
72
Describe the unhappy triad.
- aka combined knee injury
- caused by excessive lateral twisting of the flexed knee or blow to lateral side of extended knee
- abduction of leg ruptures medial collateral ligament which is attached to medial meniscus, rotation ruptures anterior cruciate ligament
- may require surgical reconstruction of the ligaments
73
What 3 structures are damaged in the unhappy triad/combined knee injury?
- medial/tibial collateral ligaement
- medial meniscus
- ACL
74
Is the patella more likely to dislocate with a smaller or greater Q angle?
Greater
75
What is the popliteal fossa?
A diamond shaped area located on the posterior aspect of the knee. It is the main pathy by which vessels and nerves pass between thigh and leg.
76
List the borders of the popliteal fossa.
- superomedial = semimembranosus
- superolateral = biceps femoris
- inferomedial = medial head of gastrocnemius
- inferolateral = lateral head of gastrocnemius and plantaris
77
What forms the floor of the popliteal fossa?
- posterior surface of knee joint capsule
- popliteus muscle
- posterior femur
78
What forms the roof of the popliteal fossa?
- popliteal fascia and skin
| - popliteal fascia is continuous with fascia lata of the leg
79
What does the popliteal fossa contain?
Medial to lateral:
- popliteal artery
- popliteal vein
- tibial nerve
- common fibular nerve
80
Describe the menisci of the knee joint.
- 2 crescent shaped wedges of fibrocartilage
- thicker at external margins
- lateral meniscus slightly smaller
81
What are the functions of the menisci of the knee?
- increase joint congruency
- distribute weight evenly
- shock absorption
- aid lubrication by facilitating movement of synovial fluid
- assist in locking mechanism
82
When might a meniscal tear occur?
Due to sports injury or degenrative damage
83
List the 6 types of meniscal tears.
- vertical
- transverse
- peripheral
- bucket handle
- parrot beak
- flap
