Lower limb anatomy Flashcards
1
Q
How many vertebrae make up vertebral column?
A
33
-7 cervical
-12 Thoracic
-5 lumbar
-5 sacral
-4 coccyx
2
Q
Name three distinguishing characteristics of vertebrae from thoracic region
A
-Heart shaped vertebral body with costal facets for articulating with head of ribs
-T1-10 thoracic vertebrae have 2 demifacets on body for articulating with head. Superior demifacet correspondds with rib at same level and inferior one corresponds with the one below
-Small circular vertebral foramen
-Long transverse processes have facets for articulation with tubercle of ribs
-Long inferiorly projecting spinous process
3
Q
Which vertebrae have a transverse foramen?
A
Cervical vertebrae
4
Q
Name the structure which passes through the transverse foramen
A
-Vertebral artery, vein and sympathetic plexus through C1-C6
-C7 transmits vertebral vein but not the artery
5
Q
What are the intervertebral discs composed of?
A
-Outer ring of concentric layers of fibrous cartilage: ‘annulus fibrosus’
-Gelatinous core ‘nucleus pulposus’
6
Q
Describe the characteristic features of each vertebra
A
Cervical
-Small vertebral bodies
-Transverse foramen (to transmit vertebral arteries)
-Short bifid spinous process (apart from C1/7)
-Large triangular vertebral foramina
Thoracic
-Heart shaped vertebral body with costal facets for articulating with head of ribs
-T1-10 thoracic vertebrae have 2 demifacets on head. Superior demifacet correspondds with rib at same level and inferior one corresponds with the one below
-Small circular vertebral foramen
-Long transverse processes have facets for articulation with tubercle of ribs
-Long inferiorly sloping spinous process
Lumbar:
-Large kidney shaped vertebral body
-Triangular vertebral foramina
-Long, thin transverse process
-Large square spinous processes
7
Q
Describe the function of the intervertebral discs
A
-lie between vertebral bodies of adjacent vertebrae forming secondary cartilaginous joints
-absorb compressive forces
8
Q
Which ligament prevents hyperflexion of the vertebral column?
A
-Posterior longitudinal ligament
-Is attached to posterior aspect of vertebral column
9
Q
What is the clinical significance of the attachment of the posterior longitudinal ligament to the discs?
A
-Function of posterior longitudinal ligament is to reinforce the annulus fibrosus
-However, ligament is weaker laterally; therefore most disc herniations occur laterally
10
Q
What is the ligamentum flavum?
A
-Unites adjacent laminae
-Limits flexion of vertebral column, assists in extending spine after flexion and helps preserve curvatures of vertebral column
11
Q
Name two tumours which commonly metastasize to the vertebrae
A
-Lung
-Prostate
-Breast
12
Q
What type of joint is the hip joint?
A
-Synovial joint
-Formed by articulation of round head of femur and cup-like acetabulum of pelvis
13
Q
Identify the points on the image (hip bone- in hip)
A
A: iliac crest
B: Posterior superior iliac spine
C: posterior inferior iliac spine
D: Greater sciatic notch
E: Lesser sciatic notch
F: Ischial tuberosity
L: ramus of ischium
K: inferior pubic ramus
J: obturator foramen
I: superior pubic ramus
H: Anterior inferior iliac spine
G: Anterior superior iliac spine
14
Q
Name the extracapusular ligaments of the hip and their attachments
A
Iliofemoral:
–> Y shaped and twisted. Originates from anterior inferior iliac spine, bifurcates and inserts either side of intertrochanteric line (resists hyperextension)
Pubofemoral
–> Originates from superior pubic ramus, inserts into intertrochanteric line (resists extension and abduction)
Ischiofemoral:
–> originates from body of ischium
–> inserts into GT of femur
(limits extension
All 3 strengthen capsule and prevent exessive ROM at hip joint. Iliofemoral is the strongest.
15
Q
Name the muscles which attach to the greater trochanter of the femur
A
Superior: piriformis
Lateral: gluteus medius
Anterior: gluteus minimus
Medial: obturator internus, gemelli superior and inferior
16
Q
Describe blood supply to hip joint
A
-Majority of blood supply to the head of femur is from retinacular arteries
-These arise as acending cervical branches from extracapsular arterial anastamosis
-Formed posteriorly by medial circumflex artery and anteriorly from branches of lateral circumflex femoral
-Minor contributions from superior and inferior gluteal arteries
-Small supply from artery of ligamentum teres (branch of obturator
17
Q
What is the clinical relevance of the blood supply to the head and neck of the femur?
A
-Intracapsular fractures of NOF disrupt retinacular vessels and compromise blood supply to femoral head
-Rupture of these vessels caused by a fracture can result in avascular necrosis of femoral head as blood supply through artery to ligamentum teres is usually inadequate
18
Q
Name the main flexor muscles of the hip?
A
Psoas and iliacus are main flexors
Additional hip flexion comes from:
-Sartorius
-Rectus femoris
-Pectineus
-Adductor longus
19
Q
What is the innervation of the hip joint?
A
The hip joint is supplied by sciatic, obturator and femoral nerves
20
Q
What is the nerve supply to the main flexor muscles of the hip?
A
Psoas: L1-L3 ventral rami
Iliacus, sartorius, rectus femoris and pectineus: Femoral nerve L2-L4
21
Q
Name the external rotators of the hip
A
Piriformis
Obturator internus and externus
Gemelli superior and inferior
Quadratus femoris
Gluteus maximus
22
Q
What are the different approaches for surgical exposure of the hip joint?
A
Posterior
Lateral
Anterior
23
Q
Muscle groups involved in moving hip
A
Flexion
–> iliopsoas
–> additional from pectineus, sartorius, rectus femoris,adductor longus
Extension
–> hamstrings
–> Gluteus maximus
Abduction
–> Gluteus medius and minimus
–> tensor fascia lata
Adduction
–> Adductor longus/magnus/brevis
–> Gracillis
Internal rotation
–> Tensor fascia lata, gluteus minimus and medius
External rotation:
–> POGQ
-Gluteus maximus
24
Q
Briefly describe the different surgical approaches to the hip joint
A
Lateral:
-Divide fibres tensor fascia lata, gluteus medius and minimus to expose femoral neck.
-Further access is gained by detaching greater trochanter from its gluteal insertions
Posterior:
-10-15cm incision 1 inch posterior to posterior edge of greater trochanter
-Incise tensor fascia lata
-Split fibres of gluteus maximus
-Detach short external rotators
-Incise capsule
25
Name the structures at risk of injury during the posterior approach?
Sciatic nerve
superior gluteal nerve
26
Name the boundaries of the femoral triangle
-Medial: medial border of adductor longus
-Lateral: medial border of sartorius
-Superior: inguinal ligament
-Floor: iliacus, psoas major, pectineus
-Roof: skin, subcut fat, fascia lata
27
Name the contents of the femoral triangle
Lateral to medial:
-Femoral nerve
-Femoral artery
-Femoral vein
-Femoral canal
28
Name the points on the image (femoral triangle):
-A: femoral nerve
-Lymph nodes
-C: Femoral vein
-D: Pectineus
-E: Iliopsoas
-F: Inguinal ligament
-G: Femoral artery
-H: great saphenous vein
-I: Adductor longus
-J: sartorius
29
What are the origins and insertions of the iliacus and psoas muscles?
-Psoas major originates along lateral surfaces of vertebral bodies of T12 and L1-L5 and their associated vertebral discs
-Iliacus originates in iliac fossa of pelvis
-Psoas major unites with iliacus at level of inguinal ligament and crosses hip joint to insert on lesser trochanter of femur
30
What is the action of iliopsoas muscle?
Flexion and lateral rotation of the hip
31
Where is the mid-inguinal point and what is the clinical significance?
-The mid-inguinal point is half way between the ASIS and the pubic symphysis
-The femoral artery can be palpated here
32
What is the femoral sheath?
-Fascial tube
-Extends 3-4 cm inferior to inguinal ligaments
-Encloses proximal parts of femoral vessels and femoral canal
-Is continuation of transversalis fascia anteriorly, iliopsoas fascia posteriorly
-Allows femoral vessels to glide deep to inguinal ligament during movement of hip
33
Name the contents of the femoral sheath
Proximal parts of:
-Femoral artery
-Femoral vein
-Femoral canal
34
What is the femoral canal?
-Femoral sheath is subdivided into three compartments (lateral, intermediate and medial) by vertical septa
-Femoral canal is medial compartment of femoral sheath
-It provides a potential space for the femoral vein to expand, during increased venous return from lower limb
35
What are the contents of the femoral canal?
-Fat
-Lymphatics
-Cloquet's node
36
What is the clinical significance of cloquet's node?
-Cloquet's node receives drainage from lower limb, perineum and anterior abdominal wall inferior to umbilicus. -Tumour or infection in this area can lead to its enlargement
37
What is the femoral ring?
The femoral ring is the entrance to the femoral canal
38
What are the boundaries of the femoral ring?
-Medial: lacunar ligament
-Posterior: pectineal ligament overlying superior pubic ramus
-Anterior: inguinal ligament
-Lateral: Femoral vein
39
What is the clinical significance of femoral ring?
-Femoral hernias can enter thigh through femoral ring
-Presents as tender mass in femoral triangle, infero-lateral to pubic tubercle
-Hernia is bounded by femoral vein laterally, lacunar ligament medially
40
Describe the course of the femoral artery
-External iliac artery becomes femoral artery once it crosses the inguinal ligament
-Enters femoral triangle and gives off profunda femoris artery ~ 4cm into femoral triangle
-Profunda femoris gives off three branches
--> perforating branches
--> medial circumflex femoral
--> lateral circumflex femoral
-Continues as superficial femoral artery in adductor canal
-Becomes popliteal artery after exiting adductor hiatus
-Gives off 5 geniculate branches in popliteal fossa
-Divides into anterior tibial artery and tibio-peroneal trunk
-Tibio-peroneal trunk divides into posterior tibial and peroneal
41
What is the function of the gluteal muscles?
Gluteus medius and minimus
--> Abduction
--> internal rotation
--> Stabilises unsupported side of pelvis to prevent it tilting during walking
Gluteus maximus
--> Hip extension
--> External rotation
--> supports extended knee via iliotibial tract e.g. standing from sitting, walking up stairs
42
What is the innervation of the gluteal muscles?
Gluteus medius: superior gluteal nerve (L5, S1)
Gluteus maximus: inferior gluteal nerve (S1, S2)
43
Other than gluteal muscles, what other group of muscles help stabilise the hip and where are they located?
-Deeper group of smaller muscles: short external rotators
-Covered by inferior half of gluteus maximus
-Laterally rotate thigh and help stabilise hip
44
Describe trendelenburg's test
-Tests function of superior gluteal nerve
-Pt is supported and asked to stand on one leg
-Pelvis on supported side should raise. If it tilts/falls, this indicates weakness of abductors on weight bearing side: a +ve 'trendelenburg test'
Rationale for test
-Superiro gluteal nerve supplies gluteus medius and minimus
-These muscles are important abductors of the hip and normally contract on contralateral side to leg being raised to stabilise hip during walking
-This allows non-weight bearing leg to swing forwards
-Dysfunction of these hip abductors results in pelvis falling/tilting when contralateral leg is raised off ground during walking
45
What are the origins of the superior and inferior gluteal arteries?
-Superior gluteal: Internal iliac posterior division: largest branch and continuation of this vessel
-Inferior gluteal: one of two terminal branches anterior division internal iliac (the other is internal pudendal)
46
Identify the points on the image (gluteal region)
A: gluteus maximus
B: superior gluteal nerve
C: inferior gluteal nerve
D: Pudendal nerve
E: Obturator internus
F: Obturator externus
G: sciatic nerve
H: semitendinosus
I: Gluteus medius
J: Gluteus minimus
K: Piriformis
L: Superior gemellus
M: Inferior gemellus
N: Quadratus femoris
O: biceps femoris (short head)
P: semimembranosu
47
What is the surface markings of piriformis?
-Line joining skin dimple of posterior superior iliac spine to superior border greater trochanter
48
Name the nerve roots of the sacral plexus and lumbosacral trunk
-Sacral plexus: S1-S4
-joined by nerve roots L4-L5 to form lumbosacral trunk
49
Name the boundaries of the greater sciatic foramen
Posterior: sacrotuberous ligament
Superior: anteiror sacroiliac ligament
Anterior: Greater sciatic notch of ilium
Inferior: sacrospinous ligament, ischial spine
50
Name the structures passing through the greater sciatic foramen above the piriformis:
-Superior gluteal nerve
-Superior gluteal vessels
51
Name the structures passing through the greater sciatic foramen below the piriformis
-Sciatic nerve
-Inferior gluteal nerve
-Inferior gluteal vessels
-Internal puendal vessels
-Pudendal nerve
-Posteiror cutaneous nerve of thigh
-Nerve to quadratus femoris
-Nerve to obturator internus
52
Name the boundaries of lesser sciatic foramen
Anterior: tuberosity of ischium
Superior: spine of ischium, sacrospinous ligament
Posterior: sacrotuberous ligament
53
Name structures passing through lesser sciatic foramen
PINTO
Pudendal nerve
Internal pudendal vessels
Nerve to obturator internus
Tendon of obturator internus
54
What is the innervation of the deeper group of gluteal muscles?
Piriformis: ventral rami S1-2
Superior gemellus: nerve to obturator internus L5-S1
Obturator internus: nerve to obturator internus L5-S1
Inferior gemellus: nerve to quadratus femoris L5-S1
Obturator externus: obturator nerve L3-l4
Quadratus femoris: nerve to quadratus femoris L5-S1
55
What are the surface markings of the sciatic nerve?
-Identify posterior superior iliac spine, greater trochanter and ischial tuberosity
-Draw curved line connecting following 3 points:
--> 2.5cm lateral to midpoint of line from PSIS to ischial tuberosity
--> midpoint between ischial tuberosity and greater trochanter
--> junction between upper 2/3rd and lower 1/3rd thigh in midline
-Nerve most commonly divides 5-7cm above posterior knee joint line
56
Describe the safe area for intramuscular gluteal injection
-Upper outer quadrant of buttock
-Avoids iatrogenic damage to sciatic nerve
57
Describe the anatomical variations of the relsationship of the sciatic nerve to the piriformis
Passes underneath piriformis in 85-90% of population
other variations:
-Piriformis divided into two parts: peroneal division passes between two parts piriformis (tibial division passes underneath as normal)
-Peroneal division of sciatic nerve passes over piriformis, tibial division passes underneath undivided muscle
-Entire nerve passes through divided piriformis
58
Identify the labels on the image (femur)
A: Head of femur
B: greater trochanter
C: neck of femur
D: intertrochanteric crest
E: Lesser trochanter
F: Gluteal tuberosity
G: Linea aspera
H: Adductor tubercle
I: lateral epicondyle
J: Medial epicondyle
K: lateral condyle
L: Intercondylar fossa
M: Medial condyle
59
What are the stages of ossificaiton of the proximal femur?
-Femoral shaft: undergoes ossification after 6 weeks in utero
-Femoral capital epiphyses: ossification 2-4 months in utero
-Femoral head: 6 months of age
-Greater trochanter: 2-4 years of age
-Lesser trochanter: puberty
60
Briefly describe 'cox vara' and 'cox valga'
-The angle of inclination that the femoral head makes with the shaft can vary with age, sex, gender and pathological processes that can weaken neck of femur such as ricketts
-Increase in angle: coxa valga
-Decrease in angle: coxa vara
Coxa vara: results in shortening of lower limb, can limit passive abduction of the hip
61
How can fractures of the femoral neck be classified, and why is their management different?
Intracapsular:
-displaced vs non displaced
Extracapsular
-Intertrochanteric
-Subtrochanteric
-Reverse oblique
Intracapsular: greater risk of avascular necrosis, smaller surface area for bony union
62
Describe the Garden classification of intracapsular fractures of the femoral neck
1: Incomplete or impacted fracture, undisplaced
2: complete fracture, undisplaced
3. complete fracture, partially displaced
4. complete fracture, fully displaced
63
Describe how you would manage an intracapsular fracture of the hip
-Garden 1+2: fixing with cannulated screws or conservative if not fit for surgery
-If displaced: THR vs hemi
THR if:
-AMTS 7 or above
-Mobilises with 1 stick or better
-Fit for the operation
64
Describe management of extracapsular fracture of hip
DHS: oblique intertrochanteric
Reverse oblique: IM nail
Subtrochanteric nail: IM nail
65
Name the muscles that make up the 'true hamstrings' and their innervations. What is the origin of the muscles?
--> True hamstrings cross hip and knee joint, and extend thigh and flex knee
--> arise from ischial tuberosity
Semitendinosus
Semimembranosus
Biceps femoris: long head only
Innervated all by tibial division sciatic nerve
short head biceps femoris:
--> peroneal division sciatic nerve
--> arise from linea aspera of femur
66
Describe function of hamstring mucles
Extend thigh and flex knee
67
How would you clinically test the function of the hamstring muscles?
Flex knee against resistance, palpate tendons on either side of popliteal fossa
68
Name adductor muscles of thigh
-Adductor longus
-Adductor magnus
-Adductor brevis
-Gracillis
69
Name the nerve supply to the medial (adductor) compartment of the thigh:
Obturator nerve except: hamstring part adductor magnus
--> tibial division sciatic nerve
70
Name the muscles which make up the quadriceps
Rectus femoris
Vastus intermedius
Vastus lateralis
Vastus medialis
71
What is the innervation of the quadriceps femoris?
Femoral nerve L2-L4
72
What is hunter's canal?
-Aponeurotic sheath located in middle 1/3rd of the antero-medial thigh
-Extends from apex of femoral triangle to adductor hiatus (defect in adductor magnus)
Provides passage for femoral vessels to reach the popliteal fossa
73
Name the boundaries of hunter's canal:
Lateral: vastus medialis
Anterior: sartorius
Posterior: adductor longus and adductor magnus
74
Name the contents of hunter's canal. What is the fate of the nerves?
-Superficial femoral artery
-Femoral vein
-saphenous nerve
-Nerve to vastus medialis
-Terminal division of obturator nerve
-Lymphatics
Nerves do not exc
75
Where is the intertrochanteric crest vs line
-Line: between trochanters anteriorly
-Crest: between trochanters posteriorly
76
What type of joint is the knee joint?
Modified hinge joint. Largest synovial joint in body
77
What is the arrangement of structures you would encounter during an arthroscopy of the knee in an anterior approach?
-Transverse meniscal ligament (stretches accross anterior horns of medial and lateral menisci)
-Anterior horn medial meniscus
-ACL
-Anterior horn lateral meniscus
-Posterior horn lateral meniscus
-PCL
-Posteiror horn meidal meniscus
78
Name the articular surfaces of the knee joint
Knee has three articular surfaces:
-Medial and lateral articulations between femoral and tibial condyles
-Intermediate articulation between patellar and femur
79
Name the attachments of the patellar ligament
Superior: apex of patellar
Inferior: tibial tuberosity
80
What is the function of the patellar ligament?
-Extends the knee joint
81
How would you test the patellar ligament?
-Patellar jerk (L3-L4)
82
Name the intra and extra-articular ligaments of the knee joint
Intra-articular:
-ACL and PCL
-posterior meniscofemoral ligament
-Popliteus tendon (intra-articular during some of its course)
Extra-articular
-Medial and lateral collaterals
83
What are the attachments of the anteiror cruciate ligament of the knee joint?
-Anterior intercondylar area of tibia
-Lateral femoral condyle
84
What are the attachments of the posterior cruciate ligament of the knee joint?
-posterior intercondylar area of tibia
-Medial femoral condyle
85
Describe the actions of the cruciate ligaments
Function is to prevent anterior/posterior displacement of the tibia relative to the femur
86
How would you test the cruciate ligaments?
Anterior and posterior draw test
87
What are the menisci?
-Crescent shaped fibrocartilages that fill that gap between the femur and the tibia
-Inner edges move freely as they aren't attached tot he bone: menisci change shape as joint moves
-Front of meniscus is anterior horn, posterior part is posterior horn, middle is body
-Outer margins are thick and well vascularised from capsule, whilst inner surfaces are thein
-Poor blood supply to inner 1/3rd of meniscus makes it difficult for tears in this part of the meniscus to heal
88
Describe injuries to the cruciate ligaments
ACL:
-When knee stops suddenly and tibia continues to move forward relative to femur
-skiing, rugby
PCL
-Less common as it is stronger
-Direct blow to flexed knee e.g. dashboard of car, or falling hard onto knee
If injury suspected
--> MRI
89
What are the salient differences between medial and lateral menisci of the knee joint?
Medial:
-Less mobile (attached to medial collateral and joint capsule)
-larger and c shaped
Lateral
-More mobile (no attachment to medial collateral)
-Smaller and circular
-Popliteus tendon runs between joint capsule and lateral mensicus
90
Why is injury to medial meniscus more common than to the lateral?
-Medial meniscus has strong attachment to the medial collateral ligmaent so is much less mobile than the lateral meniscus and therefore can't accomodate abnormal stresses as easily
91
What are the functions of the menisci of the knee?
-Shock absorbers
-Help to distribute the load by increasing the congruity of the articulation
-Contribute to joint stability
-Assist in proprioception
-Lubricate the knee joint
92
Describe the bursae aroiund the knee joint
-Suprapatellar bursa: lies between infero-anteiror surface of femur and deep surface quadriceps femoris
-Pre-patellar bursa: between patella and the skin
-Superficial and deep infrapatellar bursa: lie between the patellar ligament and skin and tibia and patellar ligament
93
What are the radiological featrues of osteoarthritis of the knee?
-Loss of joint space
-Osteophytes
-Subchondral cysts
-Subchondral sclerosis
94
What is the popliteal fossa?
Diamond shaped intermuscular region on the posterior aspect of the knee
95
Indentify the points on this image (popliteal fossa):
A1: semimembranousus
A2: semitendinosus
B: Popliteal artery
C: Medial head of gastrocnemius
D: biceps femoris
E: tibial division of sciatic nerve
F: popliteal vein
G: common peroneal nerve
H: lateral head gastrocnemius
96
Name the boundaries of the popliteal fossa:
Superomedial: semimembranosus and semitendoinosus
Superolateral: biceps femoris
Inferomedial: medial head gastrocnemius
Inferolateral: lateral head gastrocnemius
Roof: skin, subcut tissue, popliteal fascia
Floor: Popliteal surface of femur, capsule of knee joint, popliteus
97
Name the contents of the popliteal fossa
Superficial to deep:
-Common peroneal nerve
-Tibial nerve
-popliteal vein
-popliteal artery
-joint capsule
-tendon of popliteus laterally
Also contains:
-Termination of small saphenous vein as it drains into popliteal vein
-Sural nerve (arising from tibial nerve)
-Five genicular branches of popliteal artery
-Lymph nodes
-Fat
Medial to lateral
-Popliteal artery
-Popliteal vein
-Tibial division sciatic nerve
-Common peroneal division sciatic nerve
98
What is the clinical significance of the anatomy of the popliteal fossa when performing a peroneal nerve block
In peroneal nerve blocks, the common peroneal nerve is located most superficial of all the structures, followed by the popliteal vein, then the popliteal artery which is the deepest structure from the needle
99
Where does the popliteal artery commence?
When the femoral artery leaves the adductor hiatus
100
Describe the blood supply to the knee joint
-5 Genicular branches of popliteal artery supply anterior capsule and ligaments
-Arteries are lateral superior, medial superior, middle, lateral inferior and medial inferior
-Form genicular anastamosis, network of vessels around knee joint
-Other vessels contribute to anastomosis:
--> descending genicular branch femoral artery
--> decending branch of lateral femoral circumflex artery
101
What is the clinical significance of anatomy of popliteal artery?
-Relation of politeal artery to lower end of femur makes it vulnerable in supracondylar fractures
102
Describe the course of the popliteal artery as it exits the popliteal fossa
-Bifurcates when it leaves popliteal fossa: Forms anterior tibial and tibio-peroneal trunk--> peroneal and posterior tibial arteries
Branches of popliteal artery:
-Genicular branches
-Sural arteries (supply gastroc/soleus/plantaris)
-Anterior tibial and tibio-peroneal trunk
103
Describe the clinical course of the common peroneal nerve
Passes posterior to head of fibular, wraps around neck of fibula. Divides into superficial and deep peroneal branches
104
What does the superficial peroneal nerve supply?
lateral compartment
Skin over dorsum of foot including 2nd-4th webspace
105
Describe why the common peroneal nerve is vulnerable to injury
Because it runs superficial as it wraps around the neck of the fibular: vulnerable to too tight POP cast, direct blow
106
What is the clinical significance of injury to the common peroneal nerve?
It supplies the anterior and lateral compartment, and also sensation to dorsum of foot: injury results in foot drop and loss of sensation over the dorsum of foot
107
What is the differential diagnosis of a swelling in the popliteal fossa?
Popliteal artery aneurysm
Abscess
DVT
Sarcoma
Lipoma
Lymphadenopathy
Baker's cyst
108
Which cutaneous dermatome supplies sensation over the anterior and posterior aspects of the knee?
Anterior: L3 dermatome
Posterior: S1,S2
109
Describe the venous drainage of the lower leg
-Lower leg has superficial veins within the subcutaneous tissue, and deep veins beneath the deep fascia which run within the muscle with named arteries
-Both superficial and deep veins have valves
-Superficial veins include long and short saphenous veins
-Perforating veins drain superficial veins to deep veins within the muscle which are subject to compression as muscles contract deep to the fascia
110
Describe the anatomical course of the great saphenous vein
-Arises from dorsal venous arch
-Ascends 2cm anterior to medial malleolus, runs up medial aspect of tibia
-Passes posterior to medial femoral condyle at the knee, runs along medial thigh
-Empties into the sapheno-femoral junction 4cm below and lateral to the pubic tubercle
111
Describe the course of the short saphenous vein
-Arises from dorsal venous arch
-Ascends posteriorly to lateral malleolus, passes along lateral border of achilles tendon
-Empties into popliteal vein in popliteal fossa
-Sural nerve accompanies popliteal vein from popliteal fossa to lateral malleolus
112
Why is an understanding of this venous anatomy clinically significant?
Relevant for surgeons performing:
-Sapheno-venous cut-down
-varicose vein surgery
-Saphenous vein harvest for graft
113
What is the function of the valves in the perforating veins?
-prevents flow from deep veins through perforating veins into superficial system
-If they become incompetent, blood flows into superficial venous system and as a result, they become tortuous and dilated
-They then present as varicose veins
114
Why is the saphenous vein considered to be suitable graft for cardiac bypass surgery?
-Lies in superfiical fascia
-Has consistent anatomical course
-Walls have high content of muscular and elastin fibres
-Sufficient length can be harvested due to distance between tributaries and perforating veins
115
Which structure may be at risk during saphenous venous cut down?
Saphenous nerve
116
how does an injury to the saphenous nerve present?
-Sensory deficit medial lower leg, foot and ankle
-No motor deficit
117
How can you differentiate the long saphenous vein from the femoral vein at the saphenofemoral junction?
-Femoral artery lies lateral to femoral vein in femoral triangle
-Long saphenous vein receives several tributaries in region of saphenous opening, femoral vein receives only saphenous vein
-Long saphenous vein is more superficial than femoral vein
118
Describe the lymphatic drainage of the lower limb
-Lower limb drained by superfiical and deep lymphatic vessels
-Superfiical lymphatics accompany the saphenous veins and their tributaries
-Those accompanying long saphenous veins --> superficial inguinal lymph nodes --> external iliac lymph nodes
Short saphenous vein --> popliteal lymph nodes
Deep vessels from leg --> popliteal nodes --> deep inguinal nodes --> external iliac nodes
119
Name some common causes of regional inguinal lymphadenopathy
Infection of lower limb/perineum/external genitalia
Dermatitis
Syphilis
Malignancy (SCC/melanoma) lower limb and perineum
120
Name some complications following regional inguinal lymphadenectomy
Seroma
bleeding/haematoma
infection
scar
lymphoedema
121
How many compartments are there in the lower leg?
4
122
Name the compartments in the lower leg
Anterior (extensor)
Superficial posterior (flexor)
Deep posterior (flexor)
Lateral (peroneal)
123
Name the muscles in the anterior compartment
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Peroneus tertius
124
Which artery supplies the anterior compartment?
Anterior tibial artery
125
Describe the course of anterior tibial artery
Popliteal artery bifurcates at inferior popliteal fossa to tibioperoneal trunk and anterior tibial artery
Anterior artery continues in anterior compartment between extensor hallucis longus and tibialis anterior
Becomes dorsalis pedis after running beneath extensor retinaculum
Can be palpated at ankle in midpoint between two malleoli, lateral to tendon of EHL
Deep peroneal nerve accompanies anterior tibial artery throughout its course and lies lateral to artery at the ankle
126
What is the innervation of the anterior compartment?
Deep peroneal nerve
127
What is the main action of the muscles in the anterior compartment?
Dorsiflexion of ankle, extension of toes
Tibialis anterior helps with inversion at subtalar joint
Peroneus tertius helps with eversion at subtalar joint
128
Name the muscles of the lateral (peroneal) compartment
Peroneus longus
Peroneus brevis
129
Which artery supplies the lateral (peroneal) compartment?
Perforating branches from anteiror tibial artery superiorly, perforating branches from peroneal artery middle and inferiorly
Peroneal artery lies within deep posterior compartment, not peroneal compartment
130
What is the innervation of the lateral compartment?
Superficial peroneal nerve
131
Describe the action of the muscles in the lateral compartment
Plantarflexion at ankle joint
Eversion at subtalar joint
132
Name the muscles of the posterior compartment of the leg
Superficial
Gastrocneius
Soleus
Plantaris
Deep
Tibialis posterior
Flexor hallucis longus
Flexor digitorum longus
133
What is the arterial and nerve supply of the flexor compartment of the lower leg?
Artery: posterior tibial artery
Nerve: tibial nerve
134
Define compartment sydrome and describe its pathophysiology
-Compartment syndrome is a rise in interstitial fluid pressure in an osseo-fascial compartment of sufficient magnitude to induce myo-neural necrosis
-Intercompartmental septae are tough and resistant to stretch, therefore only a small rise in pressure can compress muscles and nerves resulting in microvascular injury
-Prompt diagnosis and treatment is required to avoid significant morbidity and irrerversible damage to the limb
135
What are the key signs and symptoms of compartment syndrome?
-Key sign is: pain out of proportion to the injury which fails to improve the expected time course, and is aggravated by passive muscle stretch
-Sensory loss in distribution of nerves travelling in affected compartment is also useful early sign
Other signs:
-Pulselessness
-Paraesthesia
-Paralysis
-perishing cold
-Pallor
136
Name some common causes of compartment syndrome
-Fracture
-Trauma
-Burns
-Toxins
-Too tigh POP cast
137
How would you manage compartment syndrome?
-Elevate limb
-Analgesia
-Split POP cast
-Reassess
If non resolving: fasciotomies
Anterior and lateral compartment:
-15cm incision 2cm lateral to lateral border of tibia
Posterior compartment
-15cm incision 2cm posterior to medial border of tibia (releases superficial and deep compartments)
138
What would be the threshold for intracompartmental pressure monitoring?
Difference of 30mmhg or less between intracompartmental pressure and diastolic blood pressure
139
Describe the lumbosacral plexus
-Network of nerves arising from ventral rami of L1-L5, S1-S4 nerve roots
-Nerves of lumbar plexus emerge from within psoas major and are describe in relation to this muscle
-Certain nerves arise from lumbar plexus only, others from sacral plexus only, and some from both
-Lumbosacral trunk: L4+L5 join S1-S4
140
Describe the nerves arising from the lumbar plexus and their innervation, and where they emerge from
I, I get leftovers on fridays
Iliohypogastric (L1) (H comes before I)
--> internal oblique, transversus abdominis, skin of mons pubis
Ilioinguinal (L1)
--> Skin of upper medial thigh
Genitofemoral (L1, L2)
--> Skin of external genitalia (genital branch)
--> Skin of external genitalia (femoral branch)
Lateral cutaneous nerve (L2, L3)
-SKin of lateral thigh
Obturator nerve (L2-L4)
-Adductor compartment of thigh (except hamstring part adductor magnus)
Femoral nerve (L2-L4)
-Quadriceps and sartorius
-Hip and knee joint
Where they emerge from:
-All lateral to psoas major except: genitofemoral (anterior to psoas major), Obturator (medial to psoas major)
141
Describe the nerves arising from the lumbosacral trunk and their innervation
Sciatic nerve (L4-S3)
--> Skin back of thigh, hamstring muscles, divides into tibial and common peroneal nerves
Superior gluteal nerve (L5-S1)
--> Innervation of gluteus medius and minimus and tensor fascia lata
Inferior gluteal nerve (S1-S2)
--> Innervation of gluteus maximus
Emerge from:
--> Superior gluteal nerve: greater sciatic foramen above piriformis
--> Inferior gluteal and sciatic nerve: greater sciatic foramen below piriformis
142
Describe the nerves arrising purely from the sacral plexus and their innervation
Posterior femoral cutaneous nerve (S1-3)
--> skin to posterior buttock and thigh
Pudendal nerve (S2-S4)
--> main nerve of perineum
--> cutaneous innervation of perineum and external genitalia
--> muscles of pelvic floor/perineum, external and internal urethral and anal sphincters
emerge from:
--> posteiror femoral cutaneous nerve: inferior border of gluteus maximus
--> Pudendal nerve: exits pelvis through greater sciatic foramen below piriformis, re-enters through lesser sciatic foramen
143
What are the terminal branches of the sciatic nerve?
Tibial
Common peroneal nerve
144
Describe the clinical deficit following sciatic nerve palsy
Loss of sensation to posterior thigh and lower leg below knee
Weak hip extension
Loss of all movement below the knee with foot drop
145
What is the root value of the tibial nerve?
-L4-S3
-Tibial nerve is largest terminal branch sciatic nerve
146
Name the muscles innervated by the tibial nerve
Muscles in superficial and deep posterior compartment lower leg
Gastrocnemius
Soleus
Plantaris
Popliteus
Tibialis posterior
Flexor hallucis longus
Flexor digitorum
All muscles in sole of foot via medial and lateral plantar nerves
147
What is the nerve root value of the common peroneal nerve?
L4-S2
148
Name the muscle and nerve root tested during the ankle reflex
Gastrocnemius
S1, S2 (via sciatic nerve: tibial branhc
149
How would you clinically test the L5 nerve root?
Motor: Extension of the big toe (extensor hallucis longus)
Cutaneous sensation over 1st-4th web spaces
150
Describe the blood supply to the foot
Blood supply is from two vessels: Dorsalis pedis, posterior tibial
Dorsalis pedis --> anterior tibial artery. Anastamoses with lateral plantar artery to form deep plantar arch
Posterior tibial--> splits into medial and lateral plantar arteries
Dorsalis pedis begins as anterior tibial artery enters foot. Passes over dorsal aspect of tarsal bones, then moves inferiorly towards sole of foot. Anastomoses with lateral plantar artery to form deep plantar arch. Supplies tarsal bones and dorsal aspect of metatarsals. Contributes to supply of toes via deep plantar arch.
POsterior tibial enters sole of foot via tarsal tunnel. Then splits into medial and lateral plantar arteries. These supply plantar aspect of foot and contribute to supply of toes via lateral plantar arch
151
Name the structures which pass behind the medial malleolus
Tom, Dick And Very Naughty Harry
(anterior to posterior)
Tibialis posterior
Flexor digitorum longus
Posterior tibial artery
Posterior tibial vein
Posterior tibial nerve
Flexor halluclis longus
152
Name the tarsal bones
Proximal: talus and calcaneum
Intermediate: Navicular bone
Distal: cuboid and cuneiforms
153
Name the three groups of ligaments of the ankle joint
Deltoid ligament
Syndesmosis
Lateral collateral ligamentous complex
Deltoid ligament: deep and superficial part
--> Deep: Anterior tibiotalar ligament
--> Superficial: posterior tibiotalar ligament, tibionavicular ligament, tibiocalcaneal ligament
Lateral collateral ligamentous complex:
--> Anterior and posterior talofibular ligament
--> calcaneofibular ligament
154
Name the arches of the foot
Medial longitudinal arch
Lateral longitudinal arch
Transverse arch (each foot contributes half of transverse arch)
155
Which ligament supplies the main support of the medial longitudinal arch of the foot?
-Plantar calcaneonavicular ligament (spring ligament) connects sustenaculum tali with plantar surface of navicular bone. Provides main support for medial longitudinal arch of foot
156
Describe the landmarks where you could palpate pulses in the foot and ankle
-Landmarks for palpation DP are: between tendons EHL + extensor digitorum on dorsum of foot, lateral to base of first metatarsal
POsterior tibial: Half way between medial malleolus and achilles tendon
157
How many intrinsic layers of muscles are there on the plantar aspect of the foot?
4
158
Name the muscles that make up the first layer of the plantar aspect of the foot
-abductor hallucis
-flexor digitorum brevis
-Abductor digiti minimi
159
Describe function of dorsal and plantar interossei of the foot
-Plantar interossei adduct digits
-Dorsal interossei abduct the digits. Together with the lumbricals they also flex the MTPJs and extend the PIPJs and DIPJs
160
Name the nerve which innervates the dorsal and plantar interossei
Lateral plantar nerve
161
Name the cutaneous innervation of the medial aspect of the foot
Saphenous nerve
Sural nerve supplies lateral foot
162
How are ankle fractures classified?
Weber classification
Weber A: below level of syndesmosis
Weber B: at the level of the syndesmosis
Weber C: above the level of the syndesmosis
163
What is the clinical relevance of the weber classification
Weber A: usually stable fracture, can be managed conservatively
Weber B and C: more likely to be unstable and need fixation
164
What is a stress fracture?
Incomplete fractreu caused by repeated stress, occurs most frequently to metatarsals 2, 3 and 4. Occurs most commonly in soldiers and athletes
165
What is tarsal tunnel syndrome?What are its causes?
Causative factors: pes planus (arches of feet collapse, flat foot), obesity, repetative strain, compressive lesion
entrapment of tibial nerve at level of medial malleolus below the flexor retinaculum resulting in pain and paraesthesia of sole of foot
166
How would you diagnose tarsal tunnel syndrome
-Palpating along clinical course of nerve in tarsal tunnel or percussion of nerve (tinel's test) to elicit discomfort locally or distally
-Ultrasound or MRI may help diagnose causative pathology
167
What is the management of tarsal tunnel syndrome?
Conservative management: Rest, elevation, NSAIDs, analgesia, supportive footwear, orthoses
Minimally invasive: local anaesthetic, corticosteroid
Surgical: excision of any compressive lesion/tarsal tunnel release
