Clinical Limb Joints Flashcards
1
Q
Identify these parts
A
1- clavicle
2- scapular spine
3- acromion
4- scapula superior angle
5- coracoid process
6- glenoid fossa
7- humerus head
8- greater tubercle
9- lesser tubercle
10- surgical neck
11- infraglenoid tubercle
12- supraglenoid tubercle
2
Q
What joint is affected by fall on the point of the shoulder?
A
- AC acromioclavicular joint separates, if someone falls on point of the shoulder
- Or could affect glenohumeral joint, humerus comes out anteriorly and inferiorly
3
Q
AC joint
Where is it?
When is it in danger?
A
- The acromioclavicular joint is at the top of the shoulder
- The junction between the acromion (part of the scapula that forms the highest point of the shoulder) and the clavicle
- Affected by fall on the top of the shoulder (ex: football player)
4
Q
What is the largest and most clinically significant joint of upper limb?
A
- The glenohumeral, “shoulder joint”
- Glenoid fossa of the scapula articulates with humerus head
- Ball and socket joint, allows motion in all 3 planes
- Clinically significant because the structure has sacrificed stability for range of motion.
- Shallow glenoid fossa, much larger head of the humerus
- Both covered by hyaline articular cartilage
X-ray: #6 = glenoid fossa, #7= head of humerus
5
Q
superior angle of scapula
A
4 on xray
- Where the levator scapulae attaches, for elevation of pectoral girdle
6
Q
acromion
A
*
7
Q
coracoid process
- which muscles attach there?
A
5 on xray
- coracoid process is a small hook-like structure on the lateral edge of the superior anterior portion of the scapula (coracoid = “like a raven’s beak”)
- 3 muscles attach, which cross anterior aspect of glenohumeral joint and act on it
- pectoralis minor, coracobrachialis, short head of biceps brachii
8
Q
greater and less tubercles of the humerus
A
- rotator cuff muscles attach there
xray: #s 8 and 9
9
Q
surgical neck of humerus
A
10 on xray
- clinically significant - surgical neck of the humerus
- famous because it’s where the axillary nerve and the posterior circumflex artery course around the humerus, on their way into the deltoid and teres minor
- If pt FOOSH –> fracture surgical neck of humerus –>
10
Q
- What contributes to strength of glenohumeral joint?
- Where is the weakest point?
- What happens when you dislocate the humerus at this joint?
A
STRENGTH
-
4 tendons of rotator cuff muscles (SITS) play biggest role in strengh of joint
- Supraspinatus supports superiorly - initiates ABduction (first 15*)
- Infraspinatus, teres minor (lateral/external rotators), subscapularis
- Glenoid labrum = fibrocartilagous rim to increase surface area of glenoid fossa/cavity
- Also enclosed by articular capsule
- Strengthened by glenohumeral bands - thickening of the articular capsule
WEAKNESS
- Weakest point = anteriorly and inferiorly
- When you fold at point of shoulder, separate AC joint OR dislocate head of humerus –> head of humerus goes out of anterior and inferior head of the capsule
11
Q
glenoid labrum
A
- Glenoid labrum = fibrocartilagous rim to increase surface area of glenoid fossa/cavity
12
Q
What nerves might be stretched when you dislocate head of humerus?
A
- Either the axillary nerve or the radial nerve
- More the axillary than the radial
- Because they’re situated near the surgical neck or the midshaft portion of the humerus, when it’s dislocated anteriorly and inferiorly.
13
Q
elbow joint
- Kind of joint?
- Muscles that act there?
A
-
pure hinge joint that only permits flexion and extension
- humeroradial, humeroulnar joints
- Anterior arm muscles flex forearm at elbow - biceps brachialis, brachioradialis (forearm)
- Posterior arm muscle (just the triceps) extends the forearm at the elbow
- PRonation and supination take place at the proximal radioulnar joint
14
Q
which bone attaches more securely at elbow joint?
What is the most powerful muscle that acts at the elbow joint?
A
- the ulna is the more massive bone articulating at elbow joint, and the one providing the more secure articulation
- trochlear notch of ulnea attaches to trochlea of humerus
- The more powerful muscles that act at the elbow attach to the ulna
- Brachialis = most powerful flexor of the forearm at the elbow
- Whereas the biceps brachii attaches to radial tuberosity.
15
Q
Why is “biceps curls” kind of wrong?
A
- We’re flexing biceps, but actually also flexing brachialis, which is the strongest flexer of the forearm at the elbow
16
Q
What are the 3 joints of the elbow?
A
-
Proximal radioulnar joint—allowing for articulation between the radius and ulnar bones.
- Pronation and supination - the radius moves. Ulna remains stationary.
- Humeroradial joint—allowing for movement between the humerus and radius bones.
- Humeroulnar joint—allowing for movement between the Humerus and the ulnar bones.
17
Q
at which joint do pronation and supination occur?
Which bone moves?
What are the muscles?
A
- At the proximal radioulnar joint
- Only the radius moves
- 2 supinators = biceps brachii and the supinator
- 2 pronators = pronators in anterior forearm
18
Q
what ligaments strengthen the elbow joint?
A
-
Annular ligament
- attaches to radius and ulna, and helps maintain position of radial head, in close proximity and articulating with the distal portion of the capitulum of humerus
- weak in children –> can easily dislocate radial head, lesion radial nerve –> wrist drop
-
Collateral ligaments
- Always on lateral sides of hinge joints (more important in knee)
- Prevent deviation in coronal plane
19
Q
what’s the radial nerve doing at the elbow?
A
-
radial nerve sweeps across anterior aspect of elbow joint
- Splits into deep branch - posterior interosseus nerve (emerges through supinator muscle) and superficial branch (entirely cutaneous)
- Deep branch of radial nerve = source of innervation to all muscles in extensor compartment of forearm, which extend hand at wrist and the thumb
- Splits into deep branch - posterior interosseus nerve (emerges through supinator muscle) and superficial branch (entirely cutaneous)
- Radial nerve is at risk particularly in child, since annular ligament is weak and there could be dislocation of radius and lesion to radial nerve
20
Q
carpal bones
Which are the most clinically significant?
A
- 2 rows of 4 each
- Most important are the lunate and schaphoid, because they articulate with the more massive bone at the wrist, the distal radius
- Lunate and schaphoid are at risk of trauma after FOOSH
-
Scaphoid is the most frequently fractured - pain and swelling in the anatomic snuffbox
- Quirk in blood supply - from radial artery, flows from distal to proximal. Potential for proximal part of scaphoid to undergo avascular necrosis.
- Lunate is the most frequently dislocated –> anteriorly –> latent carpal tunnel syndrome
-
Scaphoid is the most frequently fractured - pain and swelling in the anatomic snuffbox
- Note that the radius is the larger of the two wrist articulations (whereas at the elbow, the ulnar was the larger)
- Lunate and schaphoid are at risk of trauma after FOOSH
- 3rd most clinically significant is the hamate - with FOOSH, may fracture the hook of the hamate –> lesion of the ulnar nerve –> affects intrinsic hand muscles
Some Lovers Try Positions That They Cannot Handle
(or go in circle: So Long The Pinkie Here Comes The Thumb)
21
Q
quirk in blood supply around scaphoid bone?
A
- The blood supply in radial artery actually flows from distal to proximal.
- Fracture of scaphoid –> Potential for proximal part of scaphoid to undergo avascular necrosis.
- Pain and swelling in anatomic snuffbox
22
Q
trapezium
A
- carpo-metacarpal joint
- at base of thumb
- very important - allows thumb to be flexed/extended, ab/adducted
- think trapeziUM-thUMb
23
Q
metacarpalphalangeal (MP) joint -
Why is it important?
How is it different from the IP joints?
A
- MP joints have additional significance because it not only promotes flexion/extension, also allows interosseous muscles to spread our fingers
-
Extensor at MP joints = extensor digitorum muscle
- radial nerve
-
Extensor at MP joints = extensor digitorum muscle
- The proximal and distal IP joints are pure hinge joints, only permit flexion and extension
- Major extensor at IP joints = lumbricals
- 1st & 2nd lumbricals - median nerve. 3rd & 4th lumbricals - ulnar nerve.
- Major extensor at IP joints = lumbricals
24
Q
major extensor at all interphalangeal (DIP, PIP) joints?
A
- lumbrical muscles
25
what structures can you see?
* hip joint = head of femur articulates with acetabular fossa
* lesser trochanter, greater trochanter = bumps on femur
* iliopsoas attaches to the lesser
* ischial tuberosity = proximal attachment to 3 true hamstrings. We sit on it.
26
why is the lesser trochanter famous?
* **iliopsoas muscle (best flexor** of thigh at the hip) attaches there
* whereas gluteus medius and minimus attach to greater trochanter
27
3 ligaments at hip
* What are they?
* function?
* Maintain structural integrity
* As we approach full extension of the thigh at hip, they pull the femoral head more securely into the acetabulum
* From all 3 parts of pelvic bone:
* **Iliofemoral ligament**
* **Ischiofemoral ligament**
* **Pubofemoral ligament**
28
blood supply to head of femur
* **medial circumflex femoral branch** of the profunda femoral artery
* crosses the femoral neck, which is the most common femoral fracture point
* Femoral neck susceptible to fracture with osteoporosis
* Avascular necrosis of femoral head --\> total hip replacement
29
knee joint:
* kind of joint?
* what strengthens it?
* largest sinovial joint in body, but also one of the weakest
* modified hinge joint
* major actions are flexion/extension in sagittal plane, but small degrees of rotation are also possible (unlike elbow)
* strengthened by tendons of muscles that cross it, and ligaments
* Pair of **collateral ligaments** - lateral and medial
* **pez anserinus** (SGT FOT) - medial rotators
* biceps femoris tendon - lateral rotator
* quadriceps tendon
* patellar ligament
* menisci - fibrocartilagenous
* cruciate ligaments (ACL, MCL)
30
pez anserinus
* what are the 3 tendons that form it?
* what can they do at the knee?
* goose's foot
* formed by 3 tendons: SGT FOT
* **Sartorius** - Femoral nerve
* **Gracilis** - Obturator nerve
* **semiTendinosus** - Tibial nerve
* all these muscles can act as **medial rotators of the leg at the knee**
31
lateral rotator of leg?
medial rotators of leg?
* lateral - biceps femoris
* medial - SGT FOT (sartorius, gracilis, semitendinosus)
32
function of menisci?
difference between medial and lateral?
* Knee joint includes distal end of **femoral condiles + tibial plateau**
* Since the tibial plateau is flat, they can't articulate much
* **menisci** - articulate between distal end of femoral condile and tibial plateau. Enhance structural integrity, to a very small degree
* analagous to glenoid labrum in shoulder joint
* medial and lateral
* **Medial - shaped like C. Attached to medial collateral ligament, so part of terrible triad tear.**
* Lateral - shaped like o.
* shift back and forth with the condiles
33
cruciate ligaments
* play major role in attaching femur to tibia
* ACL - anterior cruciate ligament
* resists hyperflexion
* PCL - posterior cruciate ligament
* resists hyperextension
Mnemonics:
* if you cross right hand fingers and place over knee. Top is ACL.
* APEX - fibers start Anteriorly, continue Posteriorly, and EXternally to lateral femoral condile
* PAIN - Posterior, continue Anteriorly, and INternally, to medial condile of femur.
34
what are most knee injuries caused by?
what is torn?
* most knee injuries are caused by **trauma to lateral aspect of knee joint** --\> terrible triad
* stretched, strained, torn **tibial/medial collateral ligament**
* tear **medial meniscus**
* because tibial/medial collateral ligament attaches to medial meniscus. The less mobile of the two menisci.
* tear **ACL**
35
What nerve can be lesioned by lateral trauma just distal to the knee joint?
* **common fibular nerve**, sweeps around the fibular neck
* in a subcutaneous, vulnerable position
* lateral and distal to the knee joint
* so lateral trauma just distal to the knee joint --\> traumatizes the common fibular ligament --\> numbness, tingling, pain
* If serious affects the superficial/deep fibular nerves which innervate lateral/anterior leg
36
what structures do you see
37
when is the PCL most taught?
when is the ACL most taught?
* **PCL** is most taught when the knee is flexed
* resists **hyperflexion**
* **ACL** is most taught when the knee is extended
* resists **hyperextension**
* cross in both coronal and sagittal planes
* ACL starts anteriorly, goes posteriorly, externally (APEX)
38
what structures do you see?
* talus - at ankle joint. shaped like turtle shell
* **talocrural joint**
* **talus + crus** (leg)
* ****between tibia and fibula, and the talus
* **calcaneous** = bony heal, the largest of tarsus bones
* articulates with cuboid
* **navicular**
* articulates with talus
39
talocrural joint
* what forms it?
* talus + crus (leg)
* between tibia, fibula, and the talus
40
what are the joints of the foot where this happens:
inversion and eversion
plantar flexion and dorsiflexion
* Inversion and eversion occur at the **subtalar and transverse tarsal joints**
* inversion is easier
* **talocrural joint** (pure hinge) - dorsi and plantar flexion
* Ankle joint
41
talocrural joint
* pure hinge joint
* where plantar flexion/dorsiflexion occur
* strengthened by ligaments
* **medial/deltoid ligament** - very strong
* each part of it has "tibio" in its name because it attaches to tibia
* lateral ligament
* most likely to be torn from sprained ankle (excessive inversion)
42
what happens when you sprain/roll your ankle?
what is torn?
* happens at the talocrural joint, which is pure hinge
* **inversion sprain** - roll your foot with excessive inversion, toward the medial ligament of ankle joint --\>
* **tear portions of lateral ligament** of ankle joint, which is nowhere near as strong
* **anterior talofibular ligament is torn**
43
what is the important plantar arch?
* parallel plantar arches help us maintain spring in step
* medial and lateral longitudinal arches
* **medial plantar arch** is the most important of the two
* Has a keystone - the talus
* Ligaments in sole of foot maintain position of the talus between the calcanus and navicular, so maintain plantar arch
44
what do you see?
