MSK Session 5 - Knee and Thigh Flashcards
What is the femur?
- The femur is the only bone in the thigh. It is classed as a long bone, and is the longest bone in the body.
- The main function of the femur is to transmit forces from the tibia to the hip joint.
- It acts as the site of origin and attachment of many muscles and ligaments, and can be divided into three areas; proximal, shaft and distal.
Identify the structures in the proximal area of the femur.
- Head
- Neck
- Greater trochanter
- Lesser trochanter
- Intertrochanteric line
- Intertrochanteric crest
Describe the structure and function of the head in the proximal area of the femur.
- Articulates with the acetabulum of the pelvis to form the hip joint.
- It has a smooth surface with a depression on the medial aspect; for the attachment of the ligament of head of femur.
Describe the structure and function of the neck in the proximal area of the femur.
- Connects the head of the femur with the shaft.
- It is cylindrical, projecting in a superior and medial direction – this angle of projection allows for an increased range of movement at the hip joint.
Describe the structure and function of the greater trochanter in the proximal area of the femur.
- A projection of bone that originates from the anterior aspect, just lateral to the neck.
- It is angled superiorly and posteriorly, and can be found on both the anterior and posterior sides of the femur.
It is the site of attachment for many of the muscles in the gluteal region, such as gluteus medius, gluteus minimus and piriformis.
Describe the structure and function of the lesser trochanter in the proximal area of the femur.
- Smaller than the greater trochanter.
- It projects from the posteromedial side of the femur, just inferior to the neck-shaft junction.
- It is the site of attachment for the psoas major and iliacus muscles.
Describe the structure and function of the intertrochanteric line in the proximal area of the femur.
- A ridge of bone that runs in an inferomedial direction on the anterior surface of the femur, connecting the two trochanters together.
- After it passes the lesser trochanter on the posterior surface, it is known as the pectineal line.
- Site of attachment for the iliofemoral ligament (strong ligament of the hip joint).
Describe the structure and function of the intertrochanteric crest in the proximal area of the femur.
- Similar to the intertrochanteric line, this is a ridge of bone that connects the two trochanters together.
- It is located on the posterior surface of the femur.
- There is a rounded tubercle on its superior half, this is called the quadrate tubercle, which is where the quadratus femoris attaches.
Describe the features and characteristics of the femoral shaft as well as its posterior surface.
- The shaft descends in a slight medial direction. This brings the knees closer to the body’s centre of gravity, increasing stability.
- On the posterior surface of the femoral shaft, there are roughened ridges of bone, these are called the linea aspera (Latin for rough line).
Describe the features and characteristics of the proximal and distal surfaces of the femoral shaft.
- Proximally, the medial border of the linea aspera becomes the pectineal line. The lateral border becomes the gluteal tuberosity, where the gluteus maximus attaches.
- Distally, the linea aspera widens and forms the floor of the popliteal fossa, the medial and lateral borders form the medial and lateral supracondylar lines. The medial supracondylar line stops at the adductor tubercle, where the adductor magnus attaches
Briefly, describe the distal end of the femur as well as identify its key structures.
- The distal end is characterised by the presence of the medial and lateral condyles, which articulate with the tibia and patella, forming the knee joint.
- Key structures
I. Medial and lateral condyles
II. Medial and lateral epicondyles
III. Intercondylar fossa.
IV. Facet for attachment of the posterior cruciate ligament
V. Facet for attachment of anterior cruciate ligament
Describe the features of the medial and lateral condyles of the distal end of the femur.
- The Medial and lateral condyles are rounded areas at the end of the femur.
- The posterior and inferior surfaces articulate with the tibia and menisci of the knee, while the anterior surface articulates with the patella.
Describe the features of the medial and lateral epicondyles of the distal end of the femur.
- The medial and lateral epicondyles are bony elevations on the non-articular areas of the condyles.
- They are the area of attachment of some muscles and the collateral ligaments of the knee joint.
Describe the features of the intercondylar fossa of the distal end of the femur.
- The intercondylar fossa is a depression found on the posterior surface of the femur, it lies in between the two condyles.
- It contains two facets for attachment of internal knee ligaments.
Describe the features of the facet for attachment of the posterior and anterior cruciate ligaments of the distal end of the femur.
- Facet for attachment of the posterior cruciate ligament – Found on the medial wall of the intercondylar fossa, it is a large rounded flat face, where the posterior cruciate ligament of the knee attaches.
- Facet for attachment of anterior cruciate ligament – Found on the lateral wall of the intercondylar fossa, it is smaller than the facet on the medial wall, and is where the anterior cruciate ligament of the knee attaches.
What is the patella?
- The patella (knee-cap) is located at the front of the knee joint, within the patellofemoral groove of the femur.
- It attaches superiorly to the quadriceps tendon and inferiorly to the patellar ligament.
- It is classified as a sesamoid type bone due to its position within the quadriceps tendon, and is the largest sesamoid bone in the body.
Describe the bony landmarks of the patella.
- The patella has a triangular shape, with anterior and posterior surfaces.
- The apex of the patella is situated inferiorly, and is connected to the tibial tuberosity by the patella ligament.
- The base forms the superior aspect of the bone, and provides the attachment area for the quadriceps tendon.
Describe the features of the posterior surface of the patella.
The posterior surface of the patella articulates with the femur, and is marked by two facets:
- Medial facet – articulates with the medial condyle of the femur.
- Lateral facet – articulates with the lateral condyle of the femur.
What are the functions of the patella?
The patella has two main functions:
- Leg extension – Enhances the leverage that the quadriceps tendon can exert on the femur, increasing the efficiency of the muscle.
- Protection – Protects the anterior aspect of the knee joint from physical trauma.
What is the tibia?
- The tibia is the main bone of the leg, forming what is more commonly known as the shin.
- It expands at the proximal and distal ends, articulating at the knee and ankle joints respectively.
- It is the second largest bone in the body, this is due to its function as a weight bearing structure.
Describe the features and characteristics of the proximal end of the tiba.
- At the proximal end, the tibia is widened by the medial and lateral condyles, aiding in weight bearing.
- The condyles form a flat surface, known as the tibial plateau. This structure articulates with the femoral condyles to form the major articulation of the knee joint.
- Located between the condyles is a region called the intercondylar eminence – this consists of two tubercles and a roughened area.
- This area is the main site of attachment for the ligaments and the menisci of the knee joint.
- The tibial intercondylar tubercles fit into the intercondylar fossa of the femur
- On the anterior surface of the proximal tibia, inferior to the condyles, the tibial tuberosity is situated. This is where the patella ligament attaches.
Describe, briefly, the shaft of the tibia.
The shaft of the tibia has three borders and three surfaces; anterior, posterior and lateral. For brevity, only the anatomically and clinically important borders/surfaces are mentioned here.
Describe the posterior surface of the shaft of the tibia.
- The posterior surface is marked by a ridge of bone called the soleal line. It runs inferomedially, eventually blending with the medial border of the tibia. It is here where part of the soleus muscle originates.
- On the posterior surface of the tibia, there is a groove where the tibialis posterior muscle attaches.
Describe the features of the anterior and lateral borders of the shaft of the tibia.
- Anterior border – The start of the anterior border is marked by the tibial tuberosity. It is palpable down the anterior surface of the leg as the shin. Here, the periosteal covering of the tibia is susceptible to damage, presenting clinically as bruising.
- Lateral border – Also known as the interosseous border. This gives attachment to the interosseous membrane that binds the tibia and the fibula together.
Describe the features of the distal region of the tibia.
- The distal end of the tibia, like the proximal, widens to help with weight bearing.
- There is a bony projection continuing inferiorly on the medial side – this is called the medial malleolus. It articulates with the tarsal bones to form part of the ankle joint.
- Laterally, on the distal end, there is a notch, where the fibula is bound to the tibia. It is known as the fibular notch.
Describe the structure and function of the fibula.
- The fibula, along with the tibia, makes up the bones of the leg.
- The fibula is found laterally to the tibia, and is much thinner.
- As it does not articulate with the femur at the knee joint, its main function is to act as an attachment for muscles, and not as a weight bearer.
Describe the surfaces of the fibula.
- The fibular shaft has three surfaces – anterior, lateral and posterior.
- The leg is split into three compartments, and each surface faces its respective compartment e.g. anterior surface faces the anterior compartment of the leg.
- On the posterior and lateral surface of the fibular neck, the common fibular nerve can be found.
Describe the features of the distal and proximal ends of the fibula.
- At the proximal end, the fibula has an enlarged head, which contains a facet for articulation with the lateral condyle of the tibia.
- Distally, the lateral surface continues inferiorly, and is called the lateral malleolus. The lateral malleolus is more prominent than the medial malleolus, and can be palpated at the ankle on the lateral side of the leg
Describe the anterior thigh in terms of its musculature, innervation and components.
- The musculature of the thigh can be split into three sections; anterior, medial and posterior. Each compartment has a distinct innervation and function.
- The muscles in the anterior compartment of the thigh are innervated by the femoral nerve (L2-L4), and as a general rule, act to extend the leg at the knee joint.
- There are three major muscles in the anterior thigh the pectineus, satorius and the quadriceps femoris. In addition to these, the end of the iliopsoas muscle passes into the anterior compartment.
Describe the iliopsoas in terms of its structure, attachments, actions and innervation.
- Structure: The iliopsoas is actually two muscles, the psoas major and the iliacus. They originate in different areas, but come together to form a tendon, hence why they are commonly referred to as one muscle. Unlike many of the anterior thigh muscles, the iliopsoas does not extend the leg at the knee joint.
- Attachments: The psoas major originates from the lumbar vertebrae, and the iliacus originates from the iliac fossa of the pelvis. They insert together onto the lesser trochanter of the femur.
- Actions: The iliopsoas flexes the lower limb at the hip joint and assists in lateral rotation at the hip joint.
- Innervation: The psoas major is innervated by anterior rami of L1-3, while the iliacus is innervated by the femoral nerve.
Describe the proximal attachment, actions and innervation of the vastus lateralis.
- Proximal attachment: Originates from the greater trochanter and the lateral lip of linea aspera.
- Actions: Extends the knee joint and stabilises the patella.
- Innervation: Femoral nerve.
Describe the proximal attachment, actions and innervation of the vastus intermedius.
- Proximal attachment: Anterior and lateral surfaces of the femoral shaft.
- Actions: Extends the knee joint and stabilises the patella.
- Innervation: Femoral nerve.
Describe the proximal attachment, actions and innervation of the vastus medialis.
- Proximal attachment: Anterior and lateral surfaces of the femoral shaft.
- Actions: Extends the knee joint and stabilises the patella.
- Innervation: Femoral nerve.
Describe the attachments, actions and innervation of the rectus femoris.
- Attachments: Originates from the ilium, just superior to the acetabulum. It runs straight down the leg (the Latin for straight is rectus), and attaches to the patella by the quadriceps femoris tendon.
- Actions: This is the only muscle of the quadriceps to cross both the hip and knee joints. It flexes the leg at the hip joint, and extends at the knee joint.
- Innervation: Femoral nerve
Describe the structure, attachments, actions and innervation of the sartorius.
- Structure: The sartorius is the longest muscle in the body. It is long and thin, running across the thigh in a inferomedial direction. The sartorius is positioned more superficially than the other muscles in the leg.
- Attachments: Originates from the anterior superior iliac spine, and attaches to the superior, medial surface of the tibia.
- Actions: At the hip joint, it is a flexor, abductor and lateral rotator. At the knee joint, it is also a flexor.
- Innervation: Femoral nerve.
Describe the actions, innervations and attachments of the adductor magnus.
- Structure: The adductor magnus is the largest muscle in the medial compartment. It lies posteriorly to the other muscles. Functionally, the muscle can be divided into two parts; the adductor part, and the hamstring part.
- Actions: They both adduct the thigh. The adductor component also flexes the thigh, with the hamstring portion extending the thigh.
- Innervation: Adductor part is innervated by the obturator nerve (L2-L4), the hamstring part is innervated by the tibial nerve (L4-S3).
- Attachments
I. Adductor part – Originates from the inferior rami of the pubis and the rami of ischium, attaching to the linea aspera of the femur.
II. Hamstring part – Originates from the ischial tuberosity and attaches to the adductor tubercle and medial supracondylar line of the femur.
Describe the actions, innervations and attachments of the adductor longus.
- Structure: The adductor longus is a large, flat muscle. It partially covers the adductor brevis and magnus. The muscle forms the medial border of the femoral triangle.
- Attachments: Originates from the pubis, and expands into a fan shape, attaching broadly to the linea aspera of the femur.
- Actions: Adduction and medial rotation of the thigh.
- Innervation: Obturator nerve (L2-L4).
Describe the structure, attachments, actions and innervation of the adductor brevis.
- Structure: The adductor brevis is a short muscle, lying underneath the adductor longus. It lies in between the anterior and posterior divisions of the obturator nerve. Therefore, it can be used as an anatomical landmark to identify the aforementioned branches.
- Attachments: Originates from the body of pubis and inferior pubic rami. It attaches to the linea aspera on the posterior surface of the femur, proximal to the adductor longus.
- Actions: Adduction of the thigh.
- Innervation: Obturator nerve (L2-L4)
Describe the structure, attachments, actions and innervation of the obturator externus.
- Structure:This is one of the smaller muscles of the medial thigh, and it is located most superiorly.
- Attachments: It originates from the membrane of the obturator foramen, and adjacent bone. It passes under the neck of femur, attaching to the posterior aspect of the greater trochanter.
- Actions: Laterally rotates the thigh.
- Innervation: Obturator nerve (L2-L4)
Describe the structure, attachments, actions and innervation of the gracilis
- Structure: The gracilis is the most superficial and medial of the muscles in this compartment. It crosses at both the hip and knee joints. It is sometimes transplanted into the hand or forearm to replace a damaged muscle.
- Attachments: It originates from the inferior rami of the pubis, and the body of the pubis. Descending almost vertically down the leg, it attaches to the medial surface of the tibia, between the tendons of the sartorius (anteriorly) and the semitendinosus (posteriorly).
- Actions: Adduction of the thigh at the hip, and flexion of the leg at the knee.
- Innervation: Obturator nerve (L2-L4)
What is the femoral triangle?
- The femoral triangle is a hollow area in the anterior thigh.
- Many large neurovascular structures pass through this area, and can be accessed relatively easily.
- Thus, it is an area of both anatomical and clinical importance.
What are the contents of the femoral triangle?
- The femoral triangle contains some of the major neurovascular structures of the lower limb. Its contents (lateral to medial) are:
I. Femoral nerve – Innervates the anterior compartment of the thigh, and provides sensory branches for the leg and foot.
II. Femoral artery – Responsible for the majority of the arterial supply to the lower limb.
III. Femoral vein – The great saphenous vein drains into the femoral vein within the triangle.
IV. Femoral canal – A structure which contains deep lymph nodes and vessels.
- The femoral artery, vein and canal are contained within a fascial compartment – known as the femoral sheath.
Describe and identify the borders of the femoral canal.
- The femoral canal is located in the anterior thigh, within the femoral triangle.
- It can be thought of as a rectangular shaped compartment.
- It has four borders:
I. Medial border – Lacunar ligament.
II. Lateral border – Femoral vein.
III. Anterior border – Inguinal ligament.
IV. Posterior border – Pectineal ligament, superior ramus of the pubic bone, and the pectineus muscle
Describe the opening of the femoral canal.
- The opening to the femoral canal is located at its superior border, known as the femoral ring.
- The femoral ring is closed by a connective tissue layer – the femoral septum.
- This septum is pierced by the lymphatic vessels exiting the canal.
Describe the contents of the femoral canal.
- The femoral canal contains:
I. Lymphatic vessels – draining the deep inguinal lymph nodes.
II. Deep lymph node – the lacunar node.
III. Empty space.
IV. Loose connective tissue.
- The empty space allows distension of the adjacent femoral vein, so it can cope with increased venous return, or increased intra-abdominal pressure
Describe the borders of the adductor canal.
- The adductor canal is bordered by muscular structures:
I. Anterior: Sartorius.
II. Lateral: Vastus medialis.
III. Posterior: Adductor longus and adductor magnus.
- The apex of the adductor canal is marked by the adductor hiatus – a gap between the adductor and hamstring attachments of the adductor magnus.
Describe the contents of the adductor canal.
- The adductor canal serves as a passageway from structures moving between the anterior thigh and posterior leg.
- It contains the femoral artery, femoral vein, nerve to the vastus medialis and the saphenous nerve (the largest cutaneous branch of the femoral nerve).
- As the femoral artery and vein exit the canal, they become the popliteal artery and vein respectively.
Describe the nerve supply of the thigh.
Identify types of patellar fractures.
- Undisplaced
- Transverse
- Lower or upper pole
- Multifragmented undisplaced
- Multifragmented displaced
- Vertical
- Osteochondral
Be aware of the radiological features of patellar dislocation.
Describe and identify the bursae related to the knee.
- Suprapatellar bursa: between femur & quadriceps tendon, communicates with synovial membrane of the knee joint
- Prepatellar bursa: between patella & skin
- Deep infrapatellar bursa: between tibia & ligamentum patella
- Subcutaneous infrapatellar bursa: between tibial tuberosity & skin
- Popliteal bursa: between the popliteus tendon & capsule, communicates with the synovial membrane of the knee joint
Describe the clinical relevance of fractures in the femoral shaft
Describe the clinical relevance of proximal femur fractures
Outline the clinical significance of injury to the patella
Outline the clinical relevance of fractures of the tibia
Outline the clinical relevance of fractures of the fibula
Outline the clinical relevance of fractures of the carpal bones, viz. the talus and the calcaneus
Outline the clinical relevance of metatarsal fractures
What is a femoral hernia?
What is adductor canal block?
What is adductor canal compression syndrome?
What is the clinical relevance of the femoral triangle?
What is the clinical relevance of injury to the adductor muscles?
Outline the testing of the quadriceps femoris
Outline the clinical relevance of damage to the hamstring
Outline the inflammation of the bursae and the unhappy triad
Outline the clinical relevance of the collateral ligaments and the cruciate ligaments
