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

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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
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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)
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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

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5
Q

superior angle of scapula

A

4 on xray

  • Where the levator scapulae attaches, for elevation of pectoral girdle
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6
Q

acromion

A

*

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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
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8
Q

greater and less tubercles of the humerus

A
  • rotator cuff muscles attach there
    xray: #s 8 and 9
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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 –>
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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
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11
Q

glenoid labrum

A
  • Glenoid labrum = fibrocartilagous rim to increase surface area of glenoid fossa/cavity
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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.
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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
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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.
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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
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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.
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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
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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
  • 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
    • Note that the radius is the larger of the two wrist articulations (whereas at the elbow, the ulnar was the larger)
  • 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
  • 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.
24
Q

major extensor at all interphalangeal (DIP, PIP) joints?

A
  • lumbrical muscles
25
Q

what structures can you see?

A
  • 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
Q

why is the lesser trochanter famous?

A
  • iliopsoas muscle (best flexor of thigh at the hip) attaches there
  • whereas gluteus medius and minimus attach to greater trochanter
27
Q

3 ligaments at hip

  • What are they?
  • function?
A
  • 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
Q

blood supply to head of femur

A
  • 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
Q

knee joint:

  • kind of joint?
  • what strengthens it?
A
  • 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
Q

pez anserinus

  • what are the 3 tendons that form it?
  • what can they do at the knee?
A
  • 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
Q

lateral rotator of leg?

medial rotators of leg?

A
  • lateral - biceps femoris
  • medial - SGT FOT (sartorius, gracilis, semitendinosus)
32
Q

function of menisci?

difference between medial and lateral?

A
  • 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
Q

cruciate ligaments

A
  • 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
Q

what are most knee injuries caused by?

what is torn?

A
  • 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
Q

What nerve can be lesioned by lateral trauma just distal to the knee joint?

A
  • 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
Q

what structures do you see

A
37
Q

when is the PCL most taught?

when is the ACL most taught?

A
  • 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
Q

what structures do you see?

A
  • 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
Q

talocrural joint

  • what forms it?
A
  • ​talus + crus (leg)
  • ​between tibia, fibula, and the talus
40
Q

what are the joints of the foot where this happens:

inversion and eversion

plantar flexion and dorsiflexion

A
  • 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
Q

talocrural joint

A
  • 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
Q

what happens when you sprain/roll your ankle?

what is torn?

A
  • 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
Q

what is the important plantar arch?

A
  • 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
Q

what do you see?

A