Conceptual overview of lower limb and femoral triangle Flashcards
What are the different regions of the lower limb?
1) Anterior aspect:
- Anterior thigh
- Leg
- Foot
2) Posterior aspect:
- Gluteal region (don’t forget the gluteal fold)
- Posterior thigh
- Leg
- Foot
What are the joints of the lower limb?
1) Knee joint
2) Ankle joint
What are the bones of the lower bone?
1) Pelvic bone
2) Femur
3) Tibia
4) Fibula
5) Tarsal
6) Metatarsal
7) Phalanges
What are the spaces of the lower limb?
1) Femoral triangle
2) Popliteal fossa (posterior to the knee)
3) Tarsal tunnel
Structures that pass from the abdominal cavity to the anterior aspect of the thigh have to go through what?
Behind the inguinal ligament
Through which foramen do structures have to pass to go from the pelvic cavity to the posterior aspect of the thigh?
Greater sheatic foramen
The structure must pass which foramen in order to go from the pelvic cavity to the gluteal region?
Lesser sheatic foramen
Describe the structure & landmarks of the pelvic bone
- It is a combination of three bones ilium, ischium, and pubis that join together later
- Anterior landmarks:
1) Anterior superior iliac spine
2) Anterior superior iliac spine
3) Pubic tubercle (The abdominal part is till here)
4) Acetabulum (form hip joint with the femur bone)
The structure must pass which foramen in order to go from the pelvic cavity to the medial region of the thigh?
Obturator foramen
What are the general characteristics of the femur bone?
1) Greater trochanter
2) Head (joins with the acetabulum)
3) Neck
4) Lesser trochanter
5) Shaft
6) Medial epicondyle
7) Lateral epicondyle
- FYI femur is the longest bone in the body, it is a multiaxial ball and socket synovial joint
What is a femoral triangle?
- Wedge-shaped depression in the upper inner thigh
- It provides access to the femoral artery for angioplasty (to access the coronary artery to dilate a constriction through the femoral artery, so we minimize invasiveness)
- Heavy bleeding in the leg can be stopped by applying pressure in the femoral triangle
What are the boundaries of the femoral triangle?
1) Base
2) Apex (the apex does not end and continuous as a canal called the adductor canal ending as an opening called an adductor hiatus in the lower anterior aspect of the thigh)
3) Medial & lateral margin
4) Floor and roof
What forms the base of the femoral triangle?
The inguinal ligament (which is between the anterior superior iliac spine and the pubic tubercle)
What forms the lateral margin of the femoral triangle?
The medial border of the sartorius muscle (it is not in the triangle)
What forms the medial border of the femoral triangle?
medial margin of the adductor longus muscle (this muscle is in the triangle)
What forms the apex of the femoral triangle?
It is directed downwards and continuous as the adductor canal
What is the origin of the sartorius muscle?
Anterior superior iliac spine
What forms the floor of the femoral triangle?
From medial to lateral it is as follows:
1) Adductor longus muscle
2) Pectinus muscle
3) Psoas major muscle
4) Iliacus
What forms the roof of the femoral triangle?
Fascia lata (A deep fascia in the thigh)
What is the action of the sartorius muscle?
Flexes the thigh at the hip joint, and leg at the knee joint and pushes us against the ground
- Sitting while your legs are crossed demonstrates all sartorius muscle action
Where does the sartorius muscle insert?
The anterior surface of the tibia
What is the nerve supply of the sartorius muscle?
Femoral nerve
When can the sartorius muscle get paralyzed or spasemed?
During activities that makes us forcefully push off the ground
What is the function of the adductor longus muscle?
Adducts and medially rotates the thigh at the hip joint
Where does the adductor longus muscle insert?
Linea aspera, on the middle one third of the shaft of the femur
What is the origin of the adductor longus muscle?
External surface of the body of the pubis
What nerve supplies the adductor longus muscle?
Obturator nerve (since it is in the medial region)
What is the origin of psoas major muscle?
Posterior abdominal (lumbar wall transverse process, intervertebral discs adjacent and bodies from T12-L5)
Where do the psoas major muscle inserts?
lesser trochanter of femur
What is the nerve supply of the psoas major muscle?
Anterior rami of L1, 2 & 3
What is the action of the psoas major muscle?
Flexes the thigh at the hip joint
What is the origin of the iliacus muscle?
Iliac fossa
Where does the iliacus muscle insert?
Lesser trochanter of femur
What is the nerve supply of the iliacus muscle?
Femoral nerve
What is the action of the iliacus muscle?
Flexes the thigh at the hip joint
What is the relationship between the iliacus and the psoas major muscle?
They have a conjoined tendon that inserts them into the lesser trochanter posteriorly in addition to the fact that they have the same function (iliopsoas “sometime named as”)
What is the origin of the pectinus muscle?
The pectineal line of pubis
Where is the pectineus muscle inserted?
Oblique line on the posterior surface of the proximal femur
What is the action of the pectineus muscle?
1) Addution of thigh at the hip joint
2) Flexion of the thigh at the hip joint
What is the nerve supply of the pectineus muscle?
Femoral nerve
Describe the inguinal ligament
1) It attaches between the anterior superior iliac spine and the pubic tubercle
2) It is formed by the aponeurosis of the external oblique muscles
What is the function of the inguinal ligament?
Contains soft tissue as it courses anteriorly from the trunk to the anterior aspect of the lower limb
What are the contents of the femoral triangle?
- From lateral to medial (NAVI):
1) Femoral nerve
2) Femoral artery
3) Femoral vein
4) Deep inguinal lymph node
5) Femoral sheath (encloses all the structures mentioned above except the femoral vein)
What is the nerve root of the ilioinguinal nerve?
L1 (sensory nerve)
What is the nerve root of the genitofemoral nerve?
L1 and L2 (sensory nerve)
What is the nerve root of the lateral cutaneous nerve of the thigh?
L2 and L3 (sensory nerve)
What is the nerve root of the femoral nerve (anterior thigh)?
L2, L3 and L4
What is the nerve root of the obturator nerve (supplies the medial thigh)?
L2, L3, and L4
Which nerve is responsible for the sensory intervention of the femoral triangle?
Genitofemoral nerve
Describe the course of the femoral nerve
1) Behind the inguinal ligament and into the Lateral side of the femoral triangle
2) Outside the femoral sheath
3) Divides into anterior and posterior divisions
What are the branches of the femoral nerve?
1) Cutaneous branch of the anterior thigh
2) Numerous muscular branches of the anterior thigh
The posterior division continuous as the saphenous nerve which supplies the skin up the medial side of the foot
- The sensory ones are the ant and post divisions of it. The anterior division supplies some muscles in the anterior aspect and ends there, the posterior however after it also does the same continues down through the adductor canal and exits through the adductor hiatus as the saphenous nerve medially from the knee to the foot.
Describe the femoral sheath
-Between the transverse abdominus muscle and the iliacus
1) Anteriorly: Fascia transversalis (perimysium of the transverse abdominus)
2) Posteriorly: Fascia iliaca (perimysium of the iliacus)
It has three compartments (the femoral canal is medial, allows the femoral vein to expand, 1 for the lymph “femoral ring, weak site for herniation”, 1 for the vein, and one for the artery) for their arrangement of the medial most compartment with the lymph node has some space so the vein can normally expand if needed like in exercise, the other reason is the artery has high-pressure blood so when it expands it can assist in venous return.
- Superiorly it is related to the extra-peritoneal fat and parietal peritoneum
Describe the femoral hernia
The femoral ring is a weak area through which loop of the small intestine might protrude into the femoral canal and then through the saphenous opening
- It is more common in females as their hips are wider (female, fat, fetus, and fifty)
- medial to the femoral ring is a thickening called the lacunar ligament which in case of a hernia can constrict the intestines which makes the patient present with pain and if not death as it can cause ischemia and potentially necrosis in which the intestine must be removed. If there is no constriction then it is just swelling and painless
What is the origin of the femoral artery?
External iliac artery
What is the course of the femoral artery?
Ascending aorta – arch of the aorta – the descending aorta – common iliac artery (divides into)- External & internal iliac (goes to pelvis)
External iliac – limb – when it crosses the inguinal ligament 🡪 Femoral artery and it crosses the inguinal ligament at the mid-inguinal point (an imaginary line between ASIS and pubis symphysis in which its mid-point is the mid inguinal point referring to the middle of the inguinal region where the femoral artery is. (DO NOT CONFUSE THEM))
What are the different inguinal lymph nodes?
1) Superficial inguinal nodes
- In the superficial fascia, parallel to the inguinal ligament
- Lymph from the gluteal region, abdominal wall, perineum, lower superficial limb all drain into the external iliac nodes
2) Deep inguinal nodes
- Medial to the femoral vein in the femoral canal
- Receives lymph from the deep lymphatics of the thigh
- Connects with the superficial inguinal nodes
Describe the course of the femoral veins
1) Continuation of the Popliteal vein in the back of the thigh (when the popliteal vein behind the knee crosses the adductor hiatus), Becomes the External Iliac Vein under the inguinal ligament - common iliac - inferior vena cava, like the arteries it has 3 Superficial veins & 3 deep veins ultimately drain into the deep veins
2) Great saphenous vein (superficial vein above the deep fascia): enters through Saphenous opening
- One of the most common methods for gaining central venous access in emergency situations is through femoral vein cannulation
What are the branches of the femoral artery?
- Three superficial and three deep, in the femoral triangle:
1) Superficial epigastric artery (going to the stomach)
2) Superficial circumflex iliac artery (makes a turn in the iliac region)
3) Superficial external pudendal artery (pudendal refers to the perineal area)
4) Muscular arteries (for all anterior muscles of the thigh)
5) Deep external pudendal artery (deep perineal structures)
6) Profunda femoris artery (posterior deep aspect of the thigh)
- The pulse palpable in the femoral triangle inferior to the inguinal ligament midway between the anterior superior iliac spine and the pubic symphysis
