MSK Flashcards
- Provide examples of synarthroses, diarthroses and amphiarthroses
Synarthroses or fibrous joints
are joints where adjacent bones are directly connected by fibrous connective tissue. There is no synovial cavity.
Examples include:
- an interlocking suture line between adjacent bones (e.g. skull). Sutures consists of strong fibrous tissue between skull bones e.g. sagittal suture
- Syndesmoses which consist of a fibrous ligament or membrane connecting bones e.g. interosseous membrane between the radius and ulna (technically amphiarthroses as some degree of motion is permitted)
- Gomphoses which consists of periodontal ligaments tethering teeth onto sockets e.g. roots of teeth in sockets of mandible
Amphiarthroses or cartilaginous joints
can be defined by the presence of cartilage, either hyaline or fibro-, between articulating bones. There is no synovial joint cavity.
- synchrondrosis or primary cartilaginous joints are connected by hyaline cartilage. Some are temporary e.g. epiphyseal plate, first sternocostal joint, or permanent e.g. costochrondral joints. Immovable.
- symphysis or secondary cartilaginous joints are joined by fibrocartilage e.g. pubic symphysis, interbody joints between vertebral bodies and intervertebral discs. Movable.
Synovial or Diarthrodial Joints
are freely movable, but limited by surrounding joint capsule, ligaments and muscles.
Many examples: knee/hinge, shoulder/ball and socket etc
- Types: Hinge, Ball and socket, Saddle (as well as ellipsoid/condyloid, pivot, plane)
- Provide an example of a ball-and-socket, hinge, pivot, condyloid, saddle, and plane joint
- Describe the function of menisci/labrum/bursae and provide an example of each
Menisci:
pads of fibrocartilage ^[[[Histology Lecture 4]]]. Discs allow bones of different shapes to fit better, thus increasing the joint’s stability
e.g. of knee
Labrum:
a fibrocartilaginous ring which deepens the articular surface of a bone, increasing the surface area available for articulation and thus improving joint stability
e.g. in GH joint
Bursa:
sac-like structures, found between bones and adjacent structures (skin, tendons, muscle ligaments, or fibrous capsules). Bursae work to reduce friction between moving parts
e.g. supra and prepatellar bursae
- Distinguish between types of cartilage
- Articular or hyaline cartilage – e.g. found in synovial joints, cartilaginous. Appears blue or glue microscopically
- Fibrocartilage – attaches tendons and ligaments to bone. Appears white microscopically
- Elastic cartilage – auricles ^[think ear and elastic], nose, epiglottis, trachea. Appears yellow.
- Fibroelastic cartilage – intervertebral discs and intraarticular menisci (load bearing and shock absorption). Appears yellow microscopically
- Discuss the components of ground substance (PGs and collagen)
Proteoglycans
- Components of the ground substance.
- Secreted by chondrocytes
- Among collagen fibrils
- 15-40% of dry weight
- Hydrophilic - this means it attracts the water within the synovial fluid, giving the cartilage its resilient properties, permitting shock absorption (note in osteoarthritis the cartilage becomes ‘dried out’)
- Core protein plus side chains of glycosaminoglycans
- Chondroitin and keratin sulphate
- Attach to hyaluronic acid filaments (aggregation)
Collagen
- Collagen is produced by fibroblasts, as well as chondroblasts and osteoblasts
- 28 types, 90% is type 1.
- All collagen types are composed of three alpha polypeptide chains arranged like a three stranded rope
- Type 1 - skin, fascia, tendon, ligament, bone. (It is this, within the ground substance of the bone ECM (osteoid) that becomes mineralised)
- Type 2 – all forms of cartilage.
- Type 3 - in association with type 1, found in skin, artery, uterus
- Type 4 - basement membrane
- Type 5- placenta, blood vessels
- Determines the tensile strength of tissues
- Provides a framework
- Limits movement of other tissue components
- Induces platelet aggregation and clot formation
- Regulates hydroxyapatite deposition in bone (Hydroxyapatite deposition on collagen fibres confers hardness. Recall that deposition occurs in the first few days but can take months to complete calcification)
- Distinguish ligaments and tendons
Ligament
- Dense collagenous structure linking bone to bone.
- Similar to a tendon (more collagen)
- Rows of fibroblasts within extracellular matrix of mainly type 1 collagen fibres.
- Elastin allows stretch, allowing an extra degree of movement e.g. rotation at knee joint, otherwise known to be a hinge joint (uniaxial motion)
- Deformation curve gives it a crimped appearance
- Function: Prevent excessive movement.
- Injury to the ligament is termed a sprain.
Tendon
- Dense collagenous structure linking muscle to bone.
- Collagen fibrils embedded in ground substance
- A matrix of PGs, GAGs, structural glycoproteins…
- More collagen (65-75% of dry mass) and less ground substance than ligaments.
- 86% type I collagen, some elastin (2% dry mass) ^[less stretchy than ligaments]
- Very linear collagen fibre arrangement - thus no stress strain relationship as with ligaments
- Fibroblasts (tenocytes) in parallel rows between collagen bundles, synthesise collagen, elastin, PGs, and GAGs
- Carries tensile forces. ^[Think Tendon, Think Tension]
- Main injuries: tear or degeneration.
- Tendonopathy not tendonitis.
- Describe paratenon, epitenon, enthesis
Paratenon and Epitenon
- Paratenon – loose, areolar connective tissue around tendons.
- Type 1 and 3 collagen fibres, elastic fibrils and synovial cells
- Permits free movement of the tendon against surrounding structures
- Epitenon – fine connective tissue sheath covering the tendon.
- Injury – peritendonitis.
Enthesis
- Attachment of tendon to bone.
- Four zones
1. Tendon or ligament, whose collagen bundles continue into…
2. Fibrocartilage, which separates from…
3. Mineralised fibrocartilage
4. Bone
- Common site of disease in spondyloarthropathies (cause of lower back pain, j.o.interest = sacroiliac)
HII
- Discuss the main upper limb muscles (Action, attachments, innervation)
Key upper limb muscles
There are three main muscles that are of high clinical importance.
- deltoid
- attachments: the deltoid has a wide origin (lateral third anterior clavicle, acromion process, spine of scapula posterior border) inserted into deltoid tuberosity of humerus
- movements: abduction of the humerus – although it needs rotator cuff to function correctly (otherwise would simply elevate, rotator cuff holds humeral head down)
- innervation: axillary nerve, supplying it from posterior to anterior ^[susceptible to palsy with dislocation of humeral head as it wraps around it to supply deltoid]
- vascularisation: posterior circumflex humeral artery
- triceps
- features
- three heads: long, lateral, medial
- long: infraglenoid tubercle of the scapula (or inferior glenoid lip)
- lateral: posterior aspect of the humerus, superior to the radial groove (or superior lip)
- medial: posterior aspect of humerus, inferior to the radial groove on the shaft. Medial head is deep.
- attachments: inserts into posterior surface of olecranon process of ulna
- movements: elbow extension
- innervation: radial nerve
- vascularisation: deep brachial artery
- biceps
- features: long head (from glenoid labrum, arises intra-articularly), short head (from coracoid process)
- attachments: inserts into the radial tuberosity
- movements: elbow flexor and supinator
- innervation: musculocutaneous nerve
- vascularisation: muscular branches of brachial artery
- note: long head is highly susceptible to injury as it sits in bicipital groove
- pectoralis major
- attachments: from the chest wall (clavicle and sternocostal) to the lateral lip of the bicipital groove
- movements: adduction and flexion of humerus (also medially rotates the glenohumeral joint). The clavicular head flexes the glenohumeral joint and the sternocostal head extends the glenohumeral joint from the flexed position
- innervation: lateral and medial pectoral nerves supplying the two heads
- vascularisation: several (thoraco-acromial - pectoral branch, internal thoracic artery — perforating branches…)
HII
- Discuss the muscles of the forearm, and intrinsic muscles of the hand (as above)
action attachments innervation
go to forearm and hand deck
HII
- List and describe the joints of the shoulder
HII
- Describe the key ligaments of the shoulder
Two key ligaments is the coracoclavicular ligament, which has a conoid and trapezoid component; and the glenohumeral ligament, whose inferior component is the prime stabiliser of the shoulder joint. A full list is included below:
- glenohumeral ligament: divided into superior middle and inferior. Middle and inferior prevent shoulder dislocation as most dislocations are anterio-inferior. tighten with extremes of movement preventing further translation. inferior glenohumeral ligament is the prime stabiliser of the shoulder
- coracohumeral ligament:
- coracoacromial ligament:
- coracoclavicular ligament:
- acromioclavicular ligament:
- long head of biceps tendon:
HII
- Describe the key ligaments of the elbow, and key ligament/s of the wrist and fingers
There are three main ligaments that support the elbow joint: the ulnar collateral ligament, radial collateral ligament and annular ligament.
The medial collateral ligament has three bands:
- anterior (strong)
- posterior (weaker)
- oblique
The MCL is crucial for combatting valgus stress. The anterior band of MCL is especially crucial for this.
The annular ligament runs around the radial head from the anterior and the posterior margin of the radial notch, to approximate the radial head to the radial notch and enclose the radial circumference. It encircles 80% of the radial head and functions to maintain the relationship between the head of the radius and the humerus and ulna.
Function:
- Holding the proximal radius against the ulna as it fits strongly around the radial head,
- It permits for free rotation of radial head as it’s internal surface is lined with cartilage.
Note that the radial is synonymous with the lateral collateral ligament. Similarly the ulnar is synonymous with the medial collateral ligament.
- Describe the innervation and vascular supply of the upper and lower limb
Upper limb
Nerves of the upper limb
The major peripheral nerves that innervate the upper limb are the:
- Axillary
- Radial
- Musculocutaneous
- Median
- Ulnar
Innervation of upper limb muscles
- Musculocutaneous nerve: all anterior arm compartment muscles
- Median nerve: anterior forerarm compartment muscles exceptflexor carpi ulnaris muscle andmedial half of flexor digitorum profundus
- Ulnar nerve: intrinsic muscles of the hand, except for the thenar muscles and two lateral lumbrical muscles,
- Radial nerve: posterior arem and forearm compartment muscles
- Axillary nerve: deltoid and teres minor muscles
Sensory innervation of the upper limb
- Musculocutaneous nerve: skin on anterolateral forearm
- Median nerve: skin on palmar surface of the lateral three and one-half digits
- Ulnar nerve: skin on medial one and one-half digits
- Radial nerve: skin on posterior surface of forearm and dorsolateral surface of hand
- Axillary nerve: skin on lateral arm
Blood supply of the upper limb
## Arteries
The major arteries include the:
- Subclavian
- Axillary
- Brachial, continuing axillary
- Radial
- Ulnar
- Palmar arches
The deep veins accompany the arteries of the same name.
The superficial veins empty into the dorsal venous network on the posterior hand over the metacarpal bones.
The cephalic vein originates from the lateral side of the dorsal venous network and travels through the lateral forearm and arm before emptying into the axillary vein.
The basilic vein originates from the medial side of the dorsal venous network and passes into the dorsomedial aspect of the forearm. It pierces the deep fascia in the middle of the arm to become the axillary vein.
Lower limb
## Blood supply
As the external iliac artery passes under the inguinal ligament, it becomes the femoral artery.
The femoral artery passes through the femoral triangle between the femoral vein and femoral nerve. At the apex of the femoral triangle it enters the adductor canal (deep to the sartorius muscle) and then passes through the adductor hiatus of the adductor magnus muscle where it enters the popliteal fossa and becomes the popliteal artery. The popliteal artery lies deep to the tibial nerve and popliteal vein in the popliteal fossa.
- From the popliteal artery
- Five geniculate branches – middle, and medial and lateral superior and inferior geniculate arteries
- Superiors curve around the femoral condyles proximal to the epicondyles
- Inferiors course around the margins of the tibial plateau, passing under the collateral ligaments
- Anastomoses around the knee joint
- Middle and inferior arteries supply the menisci, the outer ¼ of which are vascular.
Nerve Supply
-
Three sources
- Sciatic nerve – branches from tibial and common peroneal nerves
- Femoral nerves – branches travelling via the vastus muscles
-
Obturator nerve – small nerve from posterior division, accompanies femoral artery to popliteal fossa ^[relevant in paeds: knee looks fine]
- May explain referral of hip pain to the knee
- Popliteal artery is a continuation of the femoral artery
- Below the knee it divides into the anterior and posterior tibial arteries
- The posterior tibial artery follows the course of the tibial nerve and
supplies the posterior muscles of the leg. - It passes behind the medial malleolus and passes to the plantar
aspect of the foot - Forms the medial and lateral plantar arteries which supply the
plantar structures - Below the bifurcation of the popliteal artery the peroneal artery
arises - This passes across the back of the interossesos membrane and
descends on the lateral aspect of the leg to supply the lateral
muscles - The bifurcation of the popliteal artery gives rise to the anterior tibial
artery - This passes anteriorly between the tibia and fibula across the upper
margin of the interosseous membrane and courses down the
anterior surface of this structure. - It supplies the muscles of the anterior compartment of the leg (TA,
EHL, EDL) - Reaches the dorsum of the foot as the dorsalis pedis artery
- Terminal branches are the dorsal metatarsal and dorsal digital
arteries
Nerve supply
* The main nerve to the lower leg and foot, the tibial nerve is a
continuation of the sciatic nerve.
* It enters the lower leg between the two heads of the gastrocnemius and passes deep to the soleus to enter the posterior compartment of the leg.
* The tibial nerve supplies the gastrocnemius, soleus, and the three muscles whose tendons pass behind the medial malleolus (tibialis posterior, FHL, FDL) – plantar flexors.
* Posterior tibial nerve divides into the medial and lateral plantar
nerve and sends a branch to the calcaneus
- The other division of the sciatic nerve, the common peroneal nerve arises above the knee joint.
- After passing behind the head of the fibula it wraps around the neck of the fibula and divides near here into the superficial and deep peroneal nerves.
- The superficial peroneal nerve descends adjacent to the fibula to supply peroneus longus and brevis (everters of the foot)
- The deep peroneal nerve supplies the dorsiflexors of the ankle
(anterior compartment – tibialis anterior, extensor digitorum longus, extensor hallucis longus) - It ends supplying extensor digitorum brevis
- It supplies a small area of sensation between the first two toes on the dorsum of the foot
- Identify the key features of the scapula, clavicle, humerus, radius and ulna/pelvis, tibia, fibula (Alternatively label an Xray)
Key features:
Tthe key features of the clavicle are:
- sternal end or the medial end- viewable both superiorly and inferiorly. Note that the sternal end is more flat.
- acromial end or the lateral end- viewable both superiorly and inferiorly. The acromial end is more likely to be dislocated.
- body or shaft
- conoid tubercle
- trapezoid line
- impression for costoclavicular ligament
Scapula
The scapula is a large flat bone.
Key features include:
- Body
- Spine, which terminates in the acromion laterally
- Coracoid process (coracobrachialis, pectoralis minor and short head of biceps originate here)
- Acromion, which is important because deltoid muscle attaches here, and rotator cuff muscles pass underneath. The narrowed subacromial space or downward sloping acromion pinches the cuff during elevation (see below for [[#Rotator cuff (mightily important)]])
- Glenoid cavity, articular surface with humerus
- Subscapular fossa
- Supraspinous fossa
- Infraspinous fossa
- Superior angle
- Inferior angle
- Medial border
- Lateral border
Humerus
is a long bone, and the only bone of the upper arm.
It has several key features, including:
- head
- anatomical neck, and surgical neck: note that these two terms are NOT synonymous. Anatomical neck rings around the articular surface, and separates rough humerus from smooth articular surface. Surgical neck is common site of fracture
- greater and lesser tuberosity. Note that the greater tuberosity is more lateral to the lesser tuberosity when viewed anteriorly. The lesser tuberosity is not visible at all posteriorly.
- supraspinous, infraspinous and teres minor (off rotator cuff) insert onto greater tuberosity
- subscapularis inserts onto lesser tuberosity
- bicipital groove: the long head of the biceps runs through here. Other muscles attach to the lateral lip, medial lip and floor
- lateral lip: pectoralis major
- medial lip: teres major
- floor: latissimus dorsi
- shaft
- deltoid tuberosity
- olecranon fossa
- coronoid fossa
- capitulum
- trochlea
- medial epicondyle
- lateral epicondyle
Radius
Key features of the radius include:
- head: The discoid head of the radius articulates superiorly with the capitulum of the humerus, contributing to the formation of the elbow joint. At the same time, the head of the radius also articulates with the ulna forming the proximal radioulnar joint. In this joint, the circumference of the head of the radius is situated on the radial notch of ulna.
- neck
- radial tuberosity/biceps tuberosity: where biceps inserts
- styloid process: The lateral aspect of the distal radius forms a ridge and terminates distally as the radial styloid process.
- ulnar notch: The distal end of the radius widens to form three smooth, concave surfaces. The medial aspect of the distal radius forms a concavity known as the ulnar notch, which articulates with the distal ulna.
Ulna
Key features of the ulna include:
- olecranon
- trochlear notch
- coronoid process: Projecting anteriorly from the proximal portion of the ulna is the coronoid process. The coronoid process aids in stabilizing the elbow joint and preventing hyperflexion of the forearm.
- head: The distal end of the ulna tapers to form the disc-like head of the ulna. The head of the ulna does not articulate with the carpal bones and is therefore not a component of the wrist joint
- radial notch
- ulnar tuberosity: Inferior to the coronoid process is the tuberosity of ulna, which functions as an attachment point for the brachialis muscle.
- styloid process: Projecting from the head of the ulna is a small bony protrusion known as the styloid process of ulna.
ILIUM
- superior portion of hip
- Large wing like, or fan shaped Ala
- Key features include: Iliac crest ,tubercle, four spines ASIS AIIS, PSIS, PIIS
- Like the scapula, it has flat surfaces for muscle origin
- Main weight bearer along with ischium
- Another key feature is the iliopubic eminence is junction with pubic bone
- the gluteal Surface has three lines separating gluteus max, med and min
- Tensor Fascia sits between ASIS and tubercle
- Reflected head of Rectus femoris sits above acetabulum
- ASIS is a point of attachment for Inguinal lig , Sartorius
- AIIS is a point of attachment for Straight head RF and iliofemoral lig
Pubis
- Smallest Section of the Hip
- Forms anterior inferior section of the acetabulum.
- Upper surface of body is the pubic crest which terminates laterally at the pubic tubercle
- Key features include: Superior and inferior pubic rami, pubic tubercle, obturator foramen
- Pubis and ischium border the obturator foramen
- obturator foramen is covered in a membrane, is a site of muscle attachment
- Body is quadrilateral
- Projected Laterally as Superior Ramus, joining Ilium and Ischium at Acetabulum and Inferiorly as Inferior Ramus, fuses with Ischial Ramus
- Symphysis medially located, coated with fibrocartilage, secondary cartilaginous joint ^[enables expansion during delivery for infant head]
- Upper border Body is convex
- Laterally is pubic tubercle
- 2 ridges go out laterally, upper sharp, pectineal line continues into Arcuate line
- Below this is Obturator crest, Nerve ( on Bone ) and Vessels below, over the obturator foramen
Ischium
- L shaped bone, upper portion “Body”, joins with Ilium and Pubis at acetabulum, extends down to ischial tuberosity, for sitting and Hamstrings, and lower medial, thinner bar , ischial ramus, joins the pubic ramus to enclose the Obturator foramen
- Key features: ischial tuberosity and ramus, spine
- Tuberosity has oval upper and crest below
- Hamstrings attached oval area Semimembranosus laterally and Semitendinosis and Biceps medially
- Spine of Ischium , extends medially to separate the Greater and Lesser sciatic notches
Femur
- articulates with hip at aceatbulum
- Key features include: head, neck, greater and lesser trochanter, intertrochanteric crest, shaft, linea aspera, gluteal tuberosity, patellar surface, lateral and medial epicondyles, lateral and medial condyles,
Tibia
- Major weight transmission
- Forms most of the ankle (talo-crural) joint
- Medial malleolus extends one third the way down the talus
- Medial malleolus is anterior to the lateral
- Inferior articular surface is rectangular
- Tibial tuberosity
- Medial and lateral condyles
- Shaft
- Articulates with talus and fibula
- Origin of deltoid ligament, on medial aspect, very strong
Fibula
- Lateral side of the leg, parallel with the tibia
- No or very little weight transmission
- Forms part of the ankle (talo-crural) joint
- Lateral malleolus extends more inferiorly by 1cm
- Lateral malleolus is posterior to the medial
- Head and shaft
- Articulates with the lateral surface of the talus and tibia
- Origin of important ligaments – anterior and posterior talo-fibular, calcaneo-fibular, anterior inferior tibio-fibular
See notes for X-ray
NOTE: ignores knee
- Name carpal and tarsal bones
self explanatory
Label this Xray of the lower leg
Label this Xray of the shoulder
Discuss micro and macro features of osteosarcoma
Compared to normal bone, osteosarcoma shows:
- Architecture: crowded/more cellular
- Cytology: Tumour cells often ‘spindle’ shaped, hyperchromatic, variable
- Pathognomonic feature = production of neoplastic osteoid/ matrix (appears pink due to lack of mineralisation)
- Often scanty, irregular/’lace-like’ & does not mineralize normally
- Tumor cells may also show predominantly fibrosarcomatous or chondrosarcomatous differentiation
HII
- Identify common pathologies associated with carpal bones
Scaphoid fractures
- Scaphoid within the wrist minimal soft tissue attachment
- Limited blood supply
- Retrograde supply to proximal pole
- Difficult to diagnose
- Easily missed: not very painful
- Develops avascular necrosis and arthritis untreated
- May require internal fixation
Lunate avascular necrosis
also known as Keinboch’s disease. Occurs spontaneously in 30-40 year old males.
Other issues include the trapezium developing arthritis, , arthritis developing in the junction between the pisiform and triquetral bones, hook of hamate issue causing tendon rupture.
Scapholunate ligament can tear:
- Fall or twisting Injury
- Sprained or weak wrist
- Clunk or pop with activity, weak wrist
- Predictable arthritic pattern
- Needs repair
HII
- Identify NoF fracture; describe blood supply to femoral neck and how different fractures that interfere with blood supply
- note: intracapsular fractures e.g. subcapital and transcervical will jeopardise the vascular supply of the head as it is retrograde ^[similar to scaphoid bone]
- blood supply is two-fold
- interosseous, travelling up to the head (retrograde intramedullary vessels): not affected by intracapsular fractures
- travels through capsule around neck to the head (medial and lateral circumflex femoral arteries )
- blood supply is two-fold
n.b. intra-capsular and extra-capsular fx will both cut off the intramedullary retrograde supply.
BUT, only intra-capsular fx will cut off the medial femoral circumflex artery.
HII
- What is Trendelenburg gait and what causes it?
- occurs if medius and minimus fail to fire, as they work to stabilise and keep pelvis level when opposite leg is raised
- result is opposite end drops
- causes include: loss of hip abductors, L5 radiculopathy, polio, detachment of abductors, fracture or operation on greater trochanter
- Describe the innervation (SENSORY AND MOTOR) and vascular supply of the upper limb
Innervation of upper limb muscles
Musculocutaneous nerve: all anterior arm compartment muscles
Median nerve: anterior forerarm compartment muscles except flexor carpi ulnaris muscle and medial half of flexor digitorum profundus
Ulnar nerve: intrinsic muscles of the hand, except for the thenar muscles and two lateral lumbrical muscles,
Radial nerve: posterior arem and forearm compartment muscles
Axillary nerve: deltoid and teres minor muscles
Sensory innervation of the upper limb
Musculocutaneous nerve: skin on anterolateral forearm
Median nerve: skin on palmar surface of the lateral three and one-half digits
Ulnar nerve: skin on medial one and one-half digits
Radial nerve: skin on posterior surface of forearm and dorsolateral surface of hand
Axillary nerve: skin on lateral arm
Vascular:
HII
- Label hip muscles and briefly describe their attachements, action and innervation
SEE Hip deck (gluteal muscles)
HII
- Label thigh muscles (Anterior and posterior) and briefly describe their function/Lis t and describe their function and innervation
See thigh deck
HII
- List muscles of lower leg: anterior, posterior, lateral compartments. Their attachments, innervation and action
See lower limb deck
- Describe how nerve of the lower limb arise from the sciatic nerve
links to popliteal
The sciatic nerve arises in the lumbosacral region. It descends through the posterior aspect of the thigh. Before entering the popliteal fossa, the nerve terminates by splitting into two large terminal branches: the tibial nerve and common fibular (peroneal nerve). Note that peroneal splits again into superficial and depp peroneal nerves.
LAbel Knee HII
- Label knee structures. What does ACL do? What does meniscus do?
Role of ACL:
- Prevents anterior translation of the tibia on a fixed femur
- FFAATT
- Controls rotation
- From the area between the posterior ends of the menisci
- Passes forwards, medially, and upwards
-
To antero-lateral surface of medial condyle of the femur
Note mechanism of ACL injury: non-contact injuries e.g. landings. Recurrent collapses of the knee increase the risk of osteoarthritis.
Role of meniscus:
- semilunar Cartilages
- Medial and lateral
- Crescentic pieces of fibrocartilage
- Lateral meniscus is a fuller crescent
- Attached to the periphery of the articular surfaces of the lateral and medial tibial condyles by the adjacent deep parts of the capsule – the coronary ligaments.
- Thick at the periphery, thin inner edges (wedge in cross-section)
- Upper femoral surface is concave
- Lower tibial surface is flat
- Improve congruence of joint surfaces
- Guide movement
-
Shock absorption
Mechanism of injury to menisci: semi-flexed, weight-bearing, and twist
- List the typical vertebrae features, and specific features of cervical, thoracic and lumbar vertebrae/**distinguish between cervical thoracic and lumbar vertebrae
Common features to all vertebrae include (from anterior to posterior):
- vertebral body and foramen
- pedicle
- transverse process
- articular processes
- lamina
- spinous process
Cervical vertebrae
There are seven cervical vertebrae. They are the smallest of the vertebrae.
They are characterised by:
- an uncus on either side of the vertebral body (anterior side)
- a bifid spinous process (with exceptions…C7 may not bifurcate)
- transverse foramina, in each transverse process. Through here, vertebral arteries travel to the brain
- **a triangular vertebral foramen
- **articular processes are ‘open’ ( ..allows x movement. See physiopedia)
There are several features that distinguish thoracic vertebrae:
- **spinous processes are oriented obliquely, inferiorly and posteriorly
- **articular processes are ‘reading the book’ ( ..allows x movement. See physiopedia)
- **circular vertebral foramen
- demi facets, one superior and one inferior, on either end of the vertebral body
- the demi facets articulate with the heads of two different ribs to form the costovertebral joints-
– e.g. at T2, the head of rib 2 articulates with the superior demi facet of T2, and the head of rib 3 articulates with the inferior demi facet of T2
- costal facet on the transverse process which articulates with the shaft of the rib of the same number e.g. costal facet of T2 articulates with shaft of rib 2
Special characteristics include:
- kidney shaped vertebral bodies
- **triangle shaped vertebral foramen
- shorter spinous processes c.v. thoracic vertebrae and do not extend inferiorly
- **articular processes ‘close the book’ ( ..allows x movement. See physiopedia)
Atlas
or C1. It articulates with the occiput and C2.
It has NO:
- vertebral body
- spinous process
It has:
- lateral masses, with oval-shaped superior articular facets (articulating with occipital condyles) and inferior articular facets (articulating with C2) connected by…
- anterior arch, which has a facet for articulating with the dens of the axis, which is secured by the transverse ligament of the atlas (see below)
- posterior arch, which has a groove for the vertebral artery and C1 spinal nerve
Axis
or C2, which articulates with C1 and C3.
Its most characteristic feature is the dens, in addition to the general features of the typical cervical vertebrae.
- How do the vertebrae facilitate or disallow movement?
Intervertebral joints
Vertebrae will articulate with each other via two types of joints
#### Facet (zygapophysial) joints
Facet joints are synovial plane joints, between the superior articular facets of the inferior vertebra and the inferior articular facets of the superior vertebra.
It works to guide and limit movements between vertebrae.
As synovial plane joints, the facet joints are composed of:
- hyaline articular cartilage which lines the facet surfaces of the superior and inferior articular processes
- synovial joint cavity between the articular surfaces which contains synovial fluid
- fibrous capsule, surrounding the joint, and lined by synovial membrane
- except for the anterior fibrous capsule, which is formed by the ligamentum flavum
The articular surfaces glide in a multitude of directions, which collectively produce movement in the spine of all planes:
- flexion and extension
- right and left lateral flexion
- right and left rotation
Interbody joints
Interbody joints sit between the vertebral bodies and intervertebral discs.
It is a cartilaginous symphysis.
Interbody joints connect the vertebrae anteriorly, to enable movement.
The disc is also involved in:
- weight-bearing
- shock absorption
- load distribution
- Describe the surface anatomy of the shoulder/elbow/hand/KNEE/foot
Shoulder:
At the acromion, one can palpate the acromion itself, the acromioclavicular joint, and scapular spine.
Humeral head and GT, bicipital groove can also be palpated.
Elbow:
- lateral epicondyle
- medial epicondyle
- olecranon
- radial head
- wrist:
- radial styloid
- lister’s tubercle: EPL runs around it to thumb
- ulnar styloid
Hand:
- DIPS, PIPS, MCPs
- extensor tendons
- snuffbox
- pisiform
- radial and ulnar tubercles
Knee:
- patella
- tibial tuberosity
- quadriceps tendon
- patellar tendon
- medial and lateral joint lines
Foot:
- lateral malleolus
- medial malleolus
- edl tendons
- ehl tendon
- tibialis anterior tendon
- 5th MT base
- calcaneal tendon
- **Identify the different parts of the brachial plexus, and some significant branches of the plexus
The brachial plexus can be divided into roots, trunks, divisions and cords. It provides motor and sensory innervation to the upper limb structures.
It is formed by the ventral rami of C5-T1 spinal nerves .
The plexus originates in the neck and then passes laterally and inferiorly over the first rib to enter the axilla. As it crosses the first rib, the brachial plexus is located with the axillary artery between the anterior and middle scalene muscles. This is where the roots can be found.
Trunks emerge in the posterior triangle of the neck. C5 and C6 merge to form one trunk, C7 is its own trunk, and C8 and T1 merge to form a trunk.
Divisions emerge behind the clavicle. Each trunk forms an anterior and posterior divisions.
Cords emerge in the axilla.
Three cords emerge:
- lateral: which is formed from the merging of the anterior divisions from upper and middle trunks
- posterior: which is formed from the merging of the three posterior divisions
- medial: which is formed from the merging of anterior division from lower trunk
- Axillary and radial nerves from the posterior cord - innervate posterior muscles and skin
- Musculocutaneous, median and ulnar nerves from the medial and lateral cords - innervation anterior muscles and skin
HII
- What forms the ulnar nerve (from brachial plexus)? What forms the medial nerve? The radial nerve?
- Axillary and radial nerves from the posterior cord - innervate posterior muscles and skin
- Musculocutaneous, median and ulnar nerves from the medial and lateral cords - innervation anterior muscles and skin
- List and describe the ligaments of the spinal cord
There are five main ligaments of the spine:
- the anterior longitudinal ligament which connects the anterior vertebral bodies and intervertebral discs up to the anterior tubercle of C1. The anterior atlanto-occipital membrane then connects the anterior tubercle of C1 to the occiput.
- the posterior longitudinal ligament which connects the posterior aspects of the vertebral bodies and intervertebral discs up to the C2 vertebral body. The tectorial membrane then connects C2 to the occiput
- the ligamentum flavum which is composed of elastic tissue and connects the laminae of adjacent vertebrae up to the posterior arch of C1. The posterior atlanto-occipital membrane connects the posterior arch of C1 and the occiput
- the interspinous ligament which connects adjacent spinous processes
- the supraspinous ligament which connects the tips of the spinous processes up to the C7 spinous process. It forms astrong broad ligament extending between theC7 spinous process and external occipital protuberance known as the ligamentum nuchaeand isan important site of muscle attachment
–
- transverse ligament, which is a strong thick horizontal band that passesbehind the dens of C2 as itattaches betweenthe lateral masses of C1.
- It is essential to maintaining the stability of the median atlanto-axial joint by preventing posterior displacement of the dens and anterior displacement of C1.
- Alar ligaments, which extend betweenthe sides of the dens andthe lateral margins of the foramen magnum.
- The alar ligaments prevent excessive rotation of the atlanto-axial joints.
–
- anterior longitudinal ligament = limits hyperextension of spine
- posterior longitudinal ligament = limits hyperflexion of spine; prevents posterior herniation of IVD
- ligamentum flavum = limits separation of laminae to prevent hyperflexion of spine
- interspinous ligament = prevents separation of spinous processes during flexion; resisting hyperflexion
- supraspinous = prevents separation of spinous processes during flexion; resisting hyperflexion
- transverse = resists separation of vertebral bodies?, in order to resist or limit flexion
- Describe the (relevant) layers of anterior and posterior spinal cord muscles
Posterior muscles
Layer 1
- latissimus dorsi
- function
- glenohumeral joint: extension, adduction, and medial rotation
- innervation: thoracodorsal nerve (C6 - C8 ventral rami)
- trapezius
- function
- scapula: elevation, depression, rotation and retraction
- head and neck: extension and lateral flexion
- innervation: CN XI, and C3-4 ventral rami
#### Layer 2
- levator scapulae
- function
- scapula: elevation and rotation
- neck: extension and lateral flexion
- innervation
- dorsal scapular nerve (C4,5); C3-C4 ventral rami
- rhomboids
- function
- scapula: retraction
- innervation
- dorsal scapular nerve (C4,5)
Layer 4
- splenius capitis and cervicis
- function
- head and neck: extension, lateral flexion and ipsilateral rotation
- innervation
- dorsal rami (capitis: C3 and C4?, cervicis: ‘lower cervical nerves’; c5-8?)
#### Layer 5
- erector spinae (iliocostalis, longissimus, spinalis)
- function
- spine: extension and lateral flexion
- innervation
- dorsal rami (C1-L5)
–
### Anterior muscles
Layer 1
- sternocleidomastoid
- function
- head and neck: flexion, lateral flexion and contralateral rotation
- atlanto-occipital joints: extension
- innervation
- CN XI; C2-3/4 ventral rami
##### Layer 2
- scalenes (anterior, middle and posterior)
- function
- neck: flexion, lateral flexion and rotation
- innervation
- ventral rami (C3-8?)
Deep head and neck (aka Layer 3)
- Longus capitis and colli
Superficial lumbar
- rectus abdominis, external oblique, internal oblique and transversus abdominis
- function: flexion, lateral flexion and rotation
- innervation: ventral rami
Deep lumbar
- psoas major
- function
- lumbar spine: flexion and lateral flexion
- hip joint: flexion
- innervation: ventral rami (L1-4, plus femoral nerve branches?)
- quadratus lumborum
- function
- lumbar spine: lateral flexion
- innervation: ventral rami (L12, S1-5?)
HII
- List the muscles in the six extensor compartments, and pathology associated with the extensor compartment
Extensor Tendons
- Wrist has 6 extensor compartments
- Extensor Retinaculum covers the tendons
- Prevents Bowstringing of the tendons
- Improved mechanical advantage
- Tendons are susceptible to compression friction or attrition rupture within the compartments
Extensor tendons: compartments
1. Abductor Pollicis Longus and Extensor Pollicus Brevus
2. Extensor Carpi Radialis Longus and Brevus
3. Extensor Pollicis Longus
4. Extensor Digitorum Longus and Extensor indicis Proprius
5. Extensor Digiti Minimi
6. Extensor Carpi Ulnaris
De Quervain’s Tendonitis
- Common Cause of radial wrist pain
- Over use or narrow compartment
- Treatment : Rest, Physio, stretching NSAID gel, Injection with Steroid
- Surgery if resistant
- What is wrist drop? What nerves are involved?
Wrist drop is caused by damage to the radial nerve, which travels down the arm and controls the movement of the triceps muscle at the back of the upper arm, because of several conditions. This nerve controls the backward bend of wrists and helps with the movement and sensation of the wrist and fingers.
The wrist and the fingers cannot extend at the metacarpophalangeal joints. The wrist remains partially flexed due to an opposing action of flexor muscles of the forearm. As a result, the extensor muscles in the posterior compartment remain paralyzed.
- List the contents of the carpal tunnel
The contents of the carpal tunnel are as follows:
- 4 Profundus tendons
- 4 superficialis tendons
- flexor pollicis longus
- median nerve
Carpal bones make up the walls and the floor. The tunnel was roofed by the flexor retinaculum.
**- What pathology is associated with CT? How does it occur? List risk factors, presentation and treatment
- Median nerve compression due to either reduced volume or increase in the size of structures passing through the carpal tunnel
- Intermittent paraesthesia median nerve distribution
- Wasting of thenar muscle when severe and longstanding
- Many causes including over use, pregnancy, gigantism, SLE, other inflammatory conditions
- rest ice strtch
- CS and NSAIDs
- Splint
- CT surgery
- What are the common extensor and flexor origin? List ligaments/muscles/nerves (as they apply) that attach to the common extensor origin and common flexor origin
Tendons attach around the elbow at two sites:
- common extensor origin: CEO - a blend of muscles whose tendons attach to the lateral epicondyle
- ECRB
- EDC
- ECU
- EDM
- common flexor origin: CFO - a blend of muscles whose tendons attach to the medial epicondyle
- Pronator Teres
- Flexor Carpi Radialis
- Flexor Digitorum Superficialis
- Palmaris Longus
- Flexor Carpi Ulnaris
- Describe pathology associated with CFO and CEO?
- # clinicallyrelevant : tennis elbow, or lateral epicondylitis
- Damage to the tendinous insertion common wrist and finger extensors - Pain and tenderness at common extensor origin and Lateral epicondyle - Pain with wrist and finger extension - Treated with rest and stretching, physiotherapy and cortisone injection - Rarely requires surgery to cut tendon- common flexor origin: CFO - a blend of muscles whose tendons attach to the medial epicondyle
- Pronator Teres
- Flexor Carpi Radialis
- Flexor Digitorum Superficialis
- Palmaris Longus
- Flexor Carpi Ulnaris
- # clinicallyrelevant : golfer’s elbow or medial epicondylitis
- damage to the tendinous insertion common wrist and finger flexors
- pain and tenderness at common flexor origin and medial epicondyle
- pain with wrist and finger flexion
- treated with rest and stretching, physiotherapy and cortisone injection
- rarely requires surgery
- common flexor origin: CFO - a blend of muscles whose tendons attach to the medial epicondyle
- What are the rotator cuff muscles, their attachments and actions, and innervation?
There are four muscles that comprise the rotator cuff:
- subscapularis: which originates from the whole anterior surface of the scapula and inserts on the lesser tuberosity. Subscapularis* medially rotates the glenohumeral joint. It is suppliedby the upper & lower subscapular nerves.
- supraspinatus: originates from the supraspinatus fossa and inserts on the greater tuberosity. Supraspinatus* intitiates and assists deltoid with abduction of the glenohumeral joint. Innervated by the suprascapular nerve
- infraspinatus: originate from the infraspinatus fossa and inserts on the greater tuberosity. Infraspinatus* laterally rotates the glenohumeral joint.It is innervated by the suprascapular nerve.
- teres minor: originates from the inferior angle of the scapula and inserts on the greater tuberosity. Teres minor* laterally rotates the glenohumeral joint.It is innervated by the axillary nerve.
The tendons of supraspinatus, infraspinatus and teres minor blend together at the greater tuberosity.
All of the rotator cuff muscles function to stabilise the glenohumeral joint.
The rotator cuff muscles hold down the humeral head while the deltoid abducts the arm. Without the rotator cuff muscles the deltoid would pull the head upwards.
They are actually head depressors — holds down the head while the deltoid abducts the humerus.
The rotator cuff also has a role in internal and external rotation.
- List some examples of rotator cuff disease, and broad examples of management
The rotator cuff is commonly compressed.
This leads to bursitis, and partial and full thickness tears, with pain and limited movement.
Treatment involves rest and restriction of overhead activity.
It also involves:
- anti-inflammatory medications
- physio
- cortisone injection
Sometimes surgery is required:
- arthroscopic decompression, open acromioplasty
- repair of the rotator cuff
- Patient presents with loss of sensation to dorsum of foot and foot is inverted and plantarflexed at rest. Loss of eversion and dorsiflexion. Which nerve is likely to be involved?
Deep peroneal is responsible for dorsiflexion and eversion
Foot eversion is coordinated by superficial peroneal.
Superficial nerve innervates most of dorsal surface.
Deep peroneal only innervates region betweebig and index toe.
- List the key nerves supplying the lower limb and list one or two muscles innervated by these nerves
Nerves of lower limb
The major peripheral nerves that innervate the lower limb are the:
- Femoral
- Obturator
- Sciatic. The sciatic nerve is composed of the:
- Common Peroneal (Fibular) - Superficial Peroneal (Fibular) and Deep Peroneal (Fibular) nerves
- Tibial nerve
Innervation of lower limb muscles
Femoral nerve: anterior thigh compartment muscles
Obturator nerve: medial thigh compartment muscles
Sciatic nerve: posterior thigh compartment muscles
- Superficial Peroneal (Fibular) nerve: lateral leg compartment muscles
- Deep Peroneal (Fibular) nerve: anterior leg compartment muscles
- Tibial nerve: posterior leg compartment muscles
- What structures form the sciatic foramen? What structures travel through? How can we avoid injecting the sciatic nerve?
Sciatic Foramen
- Greater and lesser sciatic notches
- Converted to Foramen by ligaments
- Sacrospinous converts Greater
- Sacrotuberous ligament converts Lesser
Ligaments and Greater Sciatic Foramen
- Sciatic Nerve, with nerve to Quadratus Femorus deep to it, lies on the ischium, one third of the way up from the ischial tuberosity to PSIS
- Sciatic Nerve can be located at the top of thigh, just medial to midpoint of GT and Ischial tuberosity ^[important NOT to inject here, instead superiorlateralquadrant]
- Pudendal nerve lies on the ligament, medial to spine
- Internal Pudendal vessels, cross the tip
- Nerve to obturator internus lies on the base of the spine
- Piriformis exits through greater foramen, sciatic nerve can be located inferior to Piriformis
- Lesser Sciatic Notch
- Obturator Internus muscle and Pudendal Vessels
List of nerves at greater sciatic notch
* 7 nerves:
* Sciatic Nerve
* Superior Gluteal Nerve
* Inferior Gluteal Nerve
* Pudendal Nerve
* Posterior Femoral Cutaneous Nerve
* Nerve to Quadratus Femoris
* Nerve to Obturator Internus
* 3 Vessel Sets:
* Superior Gluteal Artery & Vein
* Inferior Gluteal Artery & vein
* Internal Pudendal Artery & vein
* 1 Muscle:
* **Piriformis
List of nerves at lesser sciatic notch
* 2 nerves:
* Pudendal Nerve
* Nerve to Obturator Internus
* 1 Vessel Set:
* Internal Pudendal Artery & vein
* 1 Muscle:
* Obturator Internus
Upper right quadrant is site of injection
- Identify the content and borders of the femoral triangle
Femoral Triangle
- Borders
- Inguinal Ligament is base, lateral border Sartorius and medial border adductor Longus ^[this means sartorius is NOT part of the triangle, but adductor longus is]
- Floor
- Iliacus, Psoas (or iliopsoas), Pectineus, and Adductor Longus
- Contents
- Lateral to medial: Femoral nerve, artery and vein
- Identify the contents and borders of the popliteal fossa
The popliteal fossa
is the space behind the knee
Above – medial – semitendonosis and semimembranosus
Above – lateral – biceps femoris
Below – medial and lateral heads of gastrocnemius
Roof – fascia lata
Floor – popliteal surface of femur, capsule of the knee joint (oblique popliteal ligament), popliteus muscle
Contents of the popliteal fossa
Common peroneal nerve – branch of sciatic nerve- lateral, medial to biceps tendon, runs behind head of fibula.
- Tibial nerve – branch of sciatic nerve – more central, passes deep to gastrocnemius, sensory branch is the sural nerve
- Popliteal artery – from the hiatus in adductor magnus to the fibrous arch in soleus, deepest of the neurovascular structures, superiorly medial to the sciatic nerve. This will branch into peroneal; anterior and posterior tibial arteries
- popliteal vein
- sciatic nerve- which branches briefly before hand to give rise to tibial and common peroneal
- Dx for joint pain e.g. of hands
- gout: e.g. 1st MTP, knee, MCP - ‘initially’ asymmetrical monoarthritis
- RA: symmetrical polyarthritis - wrists, MCP, PIP NO DIP NO CMC
- PsA: asymmetrical poly/oligoarthritis - DIP, spinal, large joints (Shoulder, knee)
- AS: stiffening spine: mainly lumbosacral and neck; less heel knee, shoulder; virtually all SI
- OA:weightbearing, PIP, DIP, 1st CMC; spares wrist and MCP; asymmetrical polyarthritis
- Label bones of wrist and hand XR frontal
- Label bones of wrist and hand XR oblique/lateral
- Label bones of foot XR
Lateral:
- tibia
- fibula
- lateral/medial malleolus
- talus
- calcaneum
- cuboid
- navicular
- 5th MT base
Frontal:
- phalanges
- metatarsals
- cuneiforms: lateral, intermediate, middle
- cuboid
- navicular
- talus
- calcaneus
- tibia
- fibula
Medial view:
- phalanges
- metatarsals
- cuneiforms
- navicular
- cuboid
- talus
- calcaneus
- Identify wrist fracture XR
Scaphoid wrist fracture
Risk of avascular necrosis due to retrograde blood supply
- Label spine MRI and identify exiting/transiting nerves
- Label spine MRI, identify types of disc bulge
degrees etc
> 90 is disc bulge
<90 is protrusion
- Identify NoF fracture; comment on effect on vascular supply
- note: intracapsular fractures e.g. subcapital and transcervical will jeopardise the vascular supply of the head as it is retrograde ^[similar to scaphoid bone]
- blood supply is two-fold
- interosseous, travelling up to the head (retrograde intramedullary vessels): not affected by intracapsular fractures
- travels through capsule around neck to the head (medial and lateral circumflex femoral arteries )
- blood supply is two-fold
n.b. intra-capsular and extra-capsular (inter or sub trochanteric) fx will both cut off the intramedullary retrograde supply.
BUT, only intra-capsular fx will cut off the medial femoral circumflex artery.
- Describe the diagnostic criteria for SLE
- Expansion on neuropsych manifestations
- Haematology and immunological criteria are expanded
- Need 4 or more criteria with at least **1 clinical +1 **immunological laboratory criteria EXCEPT WHEN Biopsy-proven lupus nephritis
- Criteria are cumulative and need not be present concurrently
- What are the differences between intramembranous ossification and endochondral ossification?
In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue. In endochondral ossification, bone develops by replacing hyaline cartilage. Activity in the epiphyseal plate enables bones to grow in length (this is interstitial growth).
Label this Xray of the elbow
Label this Xray of the pelvis
Label this Xray of the knee
