Lower Limb Flashcards
What is the lateral border of the femoral triangle?
Sartorius muscle
What is the medial border of the femoral triangle?
Adductor longus muscle
What are the contents of the femoral triangle (lateral to medial)?
Femoral nerve Femoral artery Femoral vein Empty space Lymph canal
Where does the adductor canal start and end?
It extends from the apex of the femoral triangle to the adductor hiatus
What is in the adductor canal?
Femoral sheets creates 3 compartments for the femoral artery, femoral vein and the lymphatics.
What is the adductor canal bounded by?
Bounded anteriorly and laterally by vastus medialis
Posteriorly by adductor longus and adductor magnus
Medially by sartorius
What structure can be damaged in a superior pubic rami fracture and what consequences does this have?
Can damage the obturator nerve.
Loss of motor supply to adductor longus, brevis & Magnus, gacilis and obturator externus, leads weakened/ loss of hip adduction.
What is a femoral hernia?
A protrusion of abdominal viscera (eg a loop of the small intestine) through the femoral ring into the femoral canal medial to the femoral vein, inferolateral to the pubic tubercle.Compresses structures in the femoral triangle.
Appears clinically as a lump or bulge in the femoral triangle region.
Is a femoral hernia more common in females or males, why?
More common in females because of a wider pelvis.
How can femoral hernias lead to necrosis?
The rigid boundaries of the hernia may strangulate it and cut of the blood supply, causing avascular necrosis.
What forms the roof of the femoral triangle?
Fascia lata
What for,s the floor of the femoral triangle?
The pectineus, iliopsoas and adductor longus muscles
Where can the femoral pulse be palpated?
Midway between the ASIS and the pubic symphysis
What clinical procedure is the femoral artery used for and why? Explain this procedure
Coronary angiography, the artery is catheterised with a long thin tube that is navigated up the iliac artery, eventually to the coronary arteries. A radioactive dye is ejected into the vessels and any thickening or blockages can be visualised via x-ray imaging.
The femoral artery is located superficially in the femoral triangle, this easy to access.
Where does the femoral nerve enter the femoral triangle?
At the midpoint of the inguinal ligament
What are the functions of the hip joint?
Supports body weight in standing
Involved in locomotion
What are the three bones of the hip and when do they fuse?
The ilium, ischium and pubis.
Fusion of bones begins at 15-17 and is complete by age 20-25.
What strengthens the hip joint?
Acetabular labrum
Joint capsule
Ligaments
Muscles
What is the Acetabular labrum and how does it strengthen the hip joint?
A fibrocartilaginous rim attached to the margin of the acetabulum and the Acetabular notch.
It increases the contact of the articulating surfaces by 10%, so over 50% of the head of the femur fits in the acetabulum
Where does the hip joint capsule attach to the femur?
At the intertrochanteric line anteriorly and just below the head posteriorly (the lateral part of the posterior neck is extra-capsular)
What ligaments support the hip joint?
Iliofemoral ligament
Pubofemoral ligament
Ischiofemoral ligament
Accessory ligaments: Transverse Acetabular Ligament and the Ligamentum Teres
Describe the iliofemoral ligament
Arises from the ASIS and spreads downwards and laterally to the intertrochanteric line on the anterior side of the femoral head.
The strongest ligament of the hip, protects the hip superiorly and anteriorly.
Describe the pubofemoral ligament
Attached to the superior pubic rami and obturator crest above and blends with the joint capsule distally.
Protects the hip joint anteriorly and inferiorly, prevents over-abduction and external rotation.
What is the superior border of the Femoral triangle?
The inguinal ligament
Describe the Ischiofemoral ligament
Arises from the ischial tuberosity and extends laterally to the posterior femoral neck.
The weakest ligament. Protects the hip posteriorly, helps to stabilise the joint.
Where/what is the Ligamentum Teres?
The ligament of the head of the femur.
Travels through the fovea capitis and blends with the transverse Acetabular ligament.
Contains the obturator artery.
What is the role of the Transverse Acetabular Ligament?
Strengthens the inferior part of the acetabulum (where the acetabular notch is)
What is the blood supply to the hip joint?
Major source = the Deep Femoral artery (branches into medial and lateral circumflex arteries)
Minor source = the Obturator artery (from the ligament of the head of the femur)
How might avascular necrosis of the femoral head occur?
In a fracture of the femoral head.
This can tear retinacular arteries (branches of the circumflex arteries) and the obturator artery can not adequately supply the joint, resulting in avascular necrosis of the femoral head.
Name the bursae in the hip joint
Ischiogluteal bursa
Iliopsoas bursa
Trochanteric bursa
Gluteus medius bursa
What is hip dysplasia?
Abnormal growth of the hip eg problem with the acetabulum/head of femur/supporting capsule.
Can cause subluxation/dislocation/instability.
What is Slipped Upper Femoral Epiphysis?
Where the upper epiphysis slips in relation to the rest of the femur and causes a fracture through the physis (growth plate). The rest of the femur rides up and forward.
Ages 10-16 most affected, risk factors are obesity and endocrine diseases.
How can hip dislocations occur and how does the limb appear?
Hip dislocations require a large amount of force eg in RTAs.
Femur dislocates posteriorly, limb appears shortened and medially rotated.
What structure could a hip dislocation damage?
The sciatic nerve
How may a femoral neck fracture occur and what are possible complications?
Can occur through relatively minor trauma in the elderly.
Limb is shortened and externally rotated.
Can disrupt blood supply to head of femur and cause avascular necrosis.
Mortality rate is high (often through comorbidities)
Outline the steps in development of Rheumatoid arthritis
Synovitis: synovial membrane inflames and thickens, erodes cartilage.
Extensive cartilage loss exposes bone
Fibrous ankylosis: joint is invaded by fibrous connective tissue
Bony ankylosis: bones fuse
Where in the gluteal region is it safe to give injections?
In the upper lateral quadrant to avoid damaging the sciatic nerve
What does damage to the superior gluteal nerve result in and how can you test for it?
Weak abduction and medial rotation of the thigh due to motor loss of gluteus medius and minimus.
The patient will give a positive Trendelenburg test.
Patient will have a Gluteal Gait (characteristic ‘waddling’) where they lean away from the unsupported limb when walking to compensate.
What’s the difference between real and apparent shortening of the limb?
Real shortening is due to actual loss of bone length and apparent shortening is due to a fixed flexion deformity.
How would you measure the real length of the limb?
Put both limbs in the same position and measure from the ASIS to the medial malleolus.
How would you measure the apparent length of the limb?
But both legs parallel and measure from then umbilicus or xiphoid process to the medial malleolus.
What helps strengthen the knee joint?
Capsule Intracapsular ligaments Extracapsular ligaments Menisci Surrounding muscles
What intracapsular ligaments help stabilise the knee joint?
Anterior cruciate
Posterior cruciate
Coronary ligaments
Transverse ligament of the knee
Describe the anterior cruciate ligament
Arises from the anterior intercondylar area of the tibia, extends posteriorly and inserts laterally.
Weaker than the posterior cruciate, relatively poor blood supply.
Prevents posterior displacement of the femur on the tibia, prevents hyperextension.
Describe the posterior cruciate ligament
Arises from the posterior intercondylar area of the tibia, extends anteriorly and inserts medially.
Stronger than the anterior cruciate.
Prevents anterior displacement of the femur on the tibia, prevents hyperflexion.
In a weight bearing flexed knee, the PCL is the main stabiliser.
Where is the transverse ligament of the knee found?
Attaches the 2 menisci anteriorly.
What extracapsular ligaments help stabilise the knee joint?
Medial/Tibial collateral Lateral/Fibular collateral Oblique popliteal Arcuate popliteal Patellar
Describe the medial/tibial collateral ligament
Extends from the medial epicondyle of the femur to the medial condyle of the tibia.
Midpoint of the ligament is attached to the medial meniscus.
Weaker than the lateral collateral, more likely to be injured and is commonly torn in contact sports.
Describe the lateral/Fibular collateral ligament
Extends from the lateral epicondyle of the femur to the lateral surface of the Fibular head. Separated from the lateral menisci by the popliteus tendon.
Describe the oblique popliteal ligament
It is an expansion of the semimembranosus tendon that reinforces the joint capsule posteriorly.
Arises posterior to the medial condyle of tibia, passes towards the lateral femoral condyle
Describe the arcuate popliteal ligament
Arises from the posterior Fibular head, passes medially and spreads over the posterior surface of the joint. Strengthens the joint capsule posteriorly.
Describe the patella ligament
Is the distal part of the quadriceps femoris tendon. Passes from the apex of the patella to the tibial tuberosity.
Which muscles help stabilise the knee joint?
Quadriceps femoris, especially the inferior fibres of vastus medialis and vastus lateralis.
The iliotibial tract laterally.
What are the menisci and how do they strengthen the knee joint?
They are crescentric plates of fibrocartilage on the superior surface of the tibial condyles. Attached to the joint capsule via coronary ligaments and connected anteriorly by the joint capsule.
They deepen the surface of articulation (thicker at edges to create wedge shape) and act as shock absorbers.
Describe differences between the medial and lateral sides of the knee joint.
Medial condyles of the tibia is slightly concave, lateral is slightly convex.
Medial menisci is c-shaped, lateral is more circular.
Medial femoral condyle is larger than the lateral as it takes more weight.
What surfaces articulate in the knee joint?
Condyles of the femur articulate with condyles of the tibia.
Patella surface of the femur articulates with the articular surface of the patella.
How is the knee joint ‘locked’ in extension and ‘unlocked’?
The femur rotates internally over the tibia so the knee joint can be held in position.
To unlock the popliteus muscle helps the femur rotate externally.
What nerves innervate the knee joint?
Anteriorly: femoral nerve
Posteriorly: tibial nerve
Laterally: common Fibular nerve
What is the ‘Unhappy traid’ and how can it occur?
Damage to: the Medial Collateral ligament, Medial Meniscus, and Anterior Cruciate ligament.
Occurs via a blow to the side of the knee or lateral twisting of a flexed knee.
When can cause damage to the ACL and how can it be tested for?
Hyperextension of the knee, test using the Anterior Draw test.
When can cause damage to the PCL and how can it be tested for?
Falling onto the tibial tuberosity with a flexed knee, test using Posterior draw test.
What is a popliteal cyst (bakers cyst)?
An abnormal fluid filled sac of synovial membrane that can appear rapidly in the popliteal fossa.
What is the superior medial border of the popliteal fossa?
Semimembranosus
What is the inferior medial border of the popliteal fossa?
The medial head of gastrocnemius
What is the superior lateral border of the popliteal fossa?
Biceps femoris
What is the inferior lateral border of the popliteal fossa?
The lateral head of gastrocnemius
What are the contents of the popliteal fossa? Medial to lateral
Popliteal artery
Popliteal vein
Tibial nerve
Common fibular nerve
Give four possible causes of swelling in the popliteal fossa
Bakers cyst
Popliteal aneurysm
DVT
Tumour
What are the contents of the femoral triangle? Lateral to medial
Femoral nerve
Femoral artery
Femoral vein
Femoral canal - containing an empty space and lymph nodes
Why is the empty space in the femoral canal important?
It all the vein and lymph nodes to distend, so they can cope with different levels of flow.
What is the medial border of the femoral canal?
Lacunae ligament
What is the lateral border of the femoral canal?
Femoral vein
What is the posterior border of the femoral canal?
Pectineus muscle
