Musculoskeletal and Connective Tissue Flashcards
Unhappy Triad Context of injury? What happens? Tears? Treatment
Common injury in contact sports
Lateral force applied to planted leg
Tear of ACL, MCL (medial or tibial collateral ligament) and Meniscus (classically medial but lateral more common)
Surgical ACL reconstruction
Positive anterior drawer sign
ACL tear
Abnormal passive abduction of the leg
MCL tear
ACL attachments and function
Lateral condyle of the femur to the anterior intercondylar area of the tibia
Prevents femur from shifting backwards
PCL attachments and function
Medial condyle of the femur to the posterior intercondylar area of the tibia
Prevents femur from shifting forward
Pudendal nerve block
Function
Location
Relieve pain of delivery
Ischial Spine
Location of lumbar puncture in adults
Iliac Crest (L3-4 or L4-5)
Rotator Cuff Muscles
Function
Attachement
Innervation
“Superman Subsumes his Inferior Minors”
Supraspinatus - Abducts before deltoid. Most common injury. Attaches superiorly
Infraspinatus - Lateral rotation. Pinching injury. Attaches posteriorly
Teres Minor - Adducts and lateral rotation. Attaches posteriorly
Subscapularis - medial rotates and adducts. Attaches anteriorly
C5-C6
Writs Bones (Carpals)
"So Long To Pinky, Here Comes The Thumb" Closest to arm, Thumb to Pinky Scaphoid, Lunate, Triquetrum Closest to fingers, Pinky to Thumb Pisiform, Hamate, Capitate, Trapezoid
Most commonly fractured carpal? Other risks to this bone?
Scaphoid. Prone to avascular necrosis owing to retrograde blood supply
Cause of acute carpal tunnel syndrome
Dislocation of the lunate
Carpal Tunnel Syndrome
PathoPhys
Presentation
Entrapment of median nerve in carpal tunnel
Paresthesia, pain and numbness in median nerve area.
Median Nerve Sensation
Anterior: thumb side of hand, 1st, 2nd, and half of 3rd fingers
Posterior: 1st, 2nd, and half of 3rd fingers
Innervation of Palm of Hand
Thumb side - median nerve
Pinky side - Ulnar nerve
Innervation of Back of Hand
Thumb side - Radial nerve (superficial branch)
Pinky side - Ulnar nerve
1st, 2nd, and 3rd fingers - Median nerve
Innervation of top of shoulder?
C4
Innervation of lateral side of upper arm?
C5
Innervation of lateral side of lower arm?
C6
Innervation of medial side of lower and most of upper arm?
T1
Innervation of Axilla
T2
Injury to lower trunk of brachial plexus
What can cause it?
What does it produce?
Compressed by cervical rib or Pancoast tumor of lung
Produces Klumpke’s Palsy
How and where is Radial nerve injured Roots of radial nerve? Motor manifestation of injury? Sensory manifestation of injury? Manifestation of injury?
Compressed in axilla by incorrect use of a crutch
Lesioned by midshaft fracture of humerus in spiral groove
Deep branch stretched by subluxation of radius
Posterior cord (C5-T1)
“BEST extensors”
Brachioradialis, Extensor of wrist and fingers, Supinator, Triceps
Posterior arm and dorsal hand and thumb
Saturday night palsy (wrist drop)
How is upper trunk of brachial plexus injured?
Trauma
Axillary nerve? How is it injured? Roots? Motor manifestation of injury? Sensory manifestation of injury? Sign of injury?
Lesioned by fracture of surgical neck of humerus, dislocation of humeral head, or intramuscular injections Posterior cord (C5, C6) Deltoid paralysis (problem with abduction at shoulder). Sensory loss of deltoid muscle. Deltoid atrophy
Where is the anterior interosseous nerve injured?
Compressed in deep forearm
What is the cause of injury to recurrent branch of the median nerve?
Lesioned by superficial laceration
Bones of arm
Humerus
Ulna (pinky side)
Radius (thumb side)
Attachments of Flexor Retinaculum
Scaphoid and Trapezium to Pisiform and Hook of hamate
Abductor Pollicis Brevis Origin Insertion Innervation Action
Flexor Retinaculum, Scaphoid, Trapezius
Lateral side of proximal phalanx of the thumb
Recurrent branch of median nerve
Abducts the thumb
How does the ulnar nerve enter the hand? Possible pathology?
Through Guyon’s Canal
Guyon’s Canal Syndrome
Abductor digiti minimi Origin Insertion Innervation Action
Pisiform and tendon of flexor carpi ulnaris
Medial side of base of proximal phalanx of little finger
Ulnar nerve
Abducts little finger
hypothenar
Pinky side
Thenar
Thumb side
Flexor Pollicis Brevis Origin Insertion Innervation Action
FR and Trapezius
Base of proximal phalanx of thumb
Median nerve
Flexes thumb
Opponens Pollicis Origin Insertion Innervation Action
FR and Trapezius
1st metacarpal
Median
Opposes thumb to other digits
Adductor Pollicis Origin Insertion Innervation Action
Oblique head: Capitate and base of 2nd and 3rd metacarpals Transverse head: 3rd metacarpal Proximal phalanx of thumb Ulnar nerve Adducts thumb
Palmaris Brevis Origin Insertion Innervation Action
FR, Palmar aponeurosis
Skin of medial palm
Ulnar
Wrinkles skin
Flexor Digiti Minimi Brevis Origin Insertion Innervation Action
FR and hook of hamate
Proximal Phalanx of pinky
Ulnar
Flexes
Opponens Digiti Minimi Origin Insertion Innervation Action
FR and hook of hamate
5th metacarpal
Ulnar
Opposes pinky
Lumbriclas # Origin Insertion Innervation Action
4 Tendons of Flexor Digitorum Profundus Lateral sides of extensor expansions Lateral 2: Median Medial 2: Unlar Flexes metacarpophalangeal joints and extends interphalangeal joints
Dorsal interossei # Description Origin Insertion Innervation Action
"DAB" 4 Bipennate Adjacent sides of metacarpal bones Lateral sides of proximal phalanges Ulnar Abducts fingers, flexes metacarpophalangeal joints and extends interphalangeal joints
Palmar Interossei # Description Origin Insertion Innervation Action
"PAD" 3 Unipennate Medial side of 2nd metacarpal Lateral sides of 4th and 5th metacarpals Proximal phalanges Ulnar Adducts fingers, flexes metacarpophalangeal joints and extends interphalangeal joints
Divisions of the Brachial Plexus
"Real Texans Drink Cold Bear" Roots Trunks Divisions Cords Branches
Upper trunk of the Brachial Plexus
Roots?
Injury?
C5-C6
“Waiter’s Tip” - Erb’s Palsy
Lower Trunk of Brachial Plexus
Roots?
Injury?
C8, T1
Claw hand - Klumpke’s Palsy
Posterior Cord of Brachial Plexus
Roots?
Injury?
C5-T1
Wrist Drop
Long Thoracic Nerve
Roots?
Muscles innervated w/ function?
Context and consequences of Injury?
C5-C7
Serratus Anterior anchors scapula to thoracic cage. Used for abduction above horizontal position
Injured in mastectomy –> Winged Scapula and ipsilateral lymphedema
Musculocutaneous nerve Roots? Cause of injury? Motor deficit? Sensor deficit? Manifestation of injury?
C5-C7
Upper Trunk Compression
Biceps, Brachialis, Coracobrachialis, Flexion of arm at elbow
Lateral forearm
Difficulty flexing the elbow. Variable sensory loss
Median nerve Causes of injury? Roots Motor deficit Sensory deficit Manifestation of injury?
Compressed in supracondylar fracture of humerus producing pronator teres syndrome
Compressed in carpal tunnel syndrome and by dislocation of lunate
C5-T1
Opposition of thumb, Lateral finger flexion, Wrist flexion
Lateral hand
Decreased Thumb Function (pope’s blessing)
Ulnar Nerve Causes of injury? Roots? Motor deficit Sensory deficit? Sign
Lesioned by repeat minor traumas, Fracture of medial epicondyle of humerus, Trauma to heel of the hand, Fracture to hook of hamate
C8, T1
Medial finger flexion, Wrist flexion
Pinky side of hand
Radial deviation of wrist upon wrist flexion, Ulnar Claw
What protects the brachial plexus when the clavicle is fractured?
Subclavius muscle
Muscles innervated by Dorsal Scapular Nerve
Rhomboids and Levator Scapulae
Suprascapular nerve
What muscles does it innervate?
Roots
Supra and Infra spinatus
C5, C6
Lateral Pectoral Nerve
Roots?
Muscles innervated?
C5-C7
Pectoralis Major
Thoracodorsal Nerve
Roots
Muscles innervated
C7, C8
Latissimus Dorsi
Erb-Duchenne Palsy Nickname Site of lesion Context of injury Findings
Waiters Tip
Upper Trunk of Brachial Plexus (C5, C6)
Seen in infants following trauma during delivery
Limb hangs by side (paralysis of abductors - suprascapular and deltoid), Medially rotated (paralysis of lateral rotators), Forearm pronated (loss of biceps)
Klumpke's Palsy Site of lesion Context of injury Complication Findings
Lower trunk of brachial plexus (C8, T1)
Embryological or childbirth defect
Cervical rib can compress subclavian artery and Lower Trunk resulting in Thoracic Outlet Syndrome
Atrophy of thenar and hypothenar eminences, Atrophy of interosseous muscles, Sensory deficits on medial side of forearm and hand, Loss of radial pulse when head moved to ipsilateral side
Clawing
Loss of lumbricals which flexes the MCP joints and extends the DIP and PIP joints
Ulnar Claw
Cause of lesion
PathoPhys
Long standing injury to ulnar nerve at hook of hamate (falling)
Distal Ulnar lesion –> Loss of medial lumbricals –> inability to extend 4th and 5th digits
Medial Claw
Caused by
PathoPhys
Carpal Tunnel Syndrome or Dislocated Lunate
Distal median nerve injury (after branch containing C5-C7 branches off to feed forearm flexors) –> Loss of lateral lumbricals –> Clawing of 2nd and 3rd fingers
Pope’s Blessing
PathoPhys
Findings
Proximal median nerve lesion causes loss of lateral finger flexion and thumb opposition.
When asked to make a fist, 2nd and 3rd fingers remain extended and thumb remains unopposed
Ape Hand
Proximal median nerve lesion –> loss of opponens pollicis muscle function –> unopposable thumb (cannot abduct the thumb)
Klumpke’s Total Claw
Site of lesion
PathoPhys
Lesion to lower trunk (C8, T1) of Brachial plexus
Loss of function of all lumbricals –> Forearm finger flexors (fed by median nerve with C5-C7) and finger extensors (fed by Radial nerve) are unopposed –> clawing of all digits
Thenar eminence muscles
Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis
Hypothenar eminence mucles
Opponens digiti minimi, Abductor digiti minimi, Flexor digiti minimi
Obturator Nerve Roots Cause of injury Motor deficit Sensory deficit
L2-L4
Anterior hip dislocation
Thigh Adduction
Medial Thigh
Femoral Nerve Roots Cause of injury Motor deficit Sensory deficit
L2-L4
Pelvic fracture
Thigh flexion and leg extension
Anterior thigh and medial leg
Common Peroneal nerve Roots Cause of injury Motor deficit Sensory deficit
L4-S2
Trauma or compression of lateral aspect of leg or fibula neck fracture
“PED”
Foot eversion and dorsiflexion, toe extension, foot dropPED, foot slap, steppage gait (Peroneus longus and brevis)
Anterolateral leg and dorsal aspect of food
Tibial Nerve Roots Cause of injury Motor deficit Sensory deficit
L4-S3 Knee trauma "TIP" Foot inversion and plantarflexion (cannot stand on TIPtoes), toe flexion Sole of foot
Superior Gluteal Nerve
Roots
Cause of injury
Motor deficit
L4-S1
Posterior hip dislocation or polio
Thigh abduction (positive trendelenburg sign)
Trendelenberg Sign
What is it?
What does it mean?
Contralateral hip drop when standing on leg ipsilateral to site of lesion
Sign of injury to Gluteus minimus or medius (abductors of the hip)
Inferior Gluteal Nerve
Roots
Cause of injury
Motor deficit
L5-S2
Posterior hip dislocation
Cant jump, climb stairs, rise from seated position, push inferiorly
Sciatic nerve
Roots
Sensory area
Branches
L4-S3
Posterior thigh
Splits into common peroneal and tibial nerve
Steps of Ca entrance into skeletal muscles
- ACh binding –> muscle depolarization at motor end plate
- Depolarization travels along T tubule
- V gated Dihydrophyridine receptors mechanically coupled to Ryanodine receptors in SR
- Ca from SR enters cell
How does Ca activate muscles
- Ca –> troponin C
2. Troponin C moves tropomyosin out of myosin binding groove on actin filaments
Steps of skeletal and cardiac muscle contraction
- ATP hydrolysis cocks myosin head
- Tropomyosin displaced and myosin binds actin
- P released –> power stroke
- ADP released and ATP binds allowing separation of myosin and actin
During contraction, what happens to the bands in the skeletal muscle
Shortening H and I bands and between Z line (HIZ shrinkage)
A band remains the same length (A always the same)
Type 1 Muscle Speed Length of contraction Color Primary Reaction
“1 Slow Red Ox”
Slow twitch, Sustained contraction
Red fibers (from ↑ mito and myoglobin)
Oxidative phosphorylation
Type 2 Muscle Speed Color Primary Reaction What kind of training affects them?
Fast twitch
White fibers (↓ mito and myoglobin)
Anaerobic glycolysis
Weight training –> hypertrophy
Z line
Where actin attaches to backbone
I band
Just Actin
H band
Just Myosin
A band
Myosin + Where Myosin overlaps with Actin
M line
Center of myosin
Endochondral Ossification
Which bones form this way?
Process
Axial and appendicular skeleton and base of skull
Cartilaginous model of bone is made by chondrocytes. Osteoclasts and Osteoblasts later replace with woven bone and then remodel to lamellar bone
In adults, when does woven bone occur?
After fractures or in Paget’s disease
Membranous ossification
Which bones form this way?
Process
Calavarium and facial bones
Woven bone forms directly w/o cartilage. Later remodeled to lamellar bone
Osteoblasts
Function
Derived from?
Build Bone by secreting collagen and catalyzing mineralization
Differentiate from mesenchymal stem cells in periosteum
Osteoclasts
Histo
Function
Derived from?
Multinucleated cells
Dissolve bone by secreting acid and collagenases
Differentiate from monocytes/macrophages
Affects of PTH on Bone
At low, intermittent levels, exert anabolic affects (building bone) on osteoblasts and (indirectly) osteoclasts.
Primary hyperparathyroidism –> catabolic affects (osteitis fibrosa cystica)
Affects of Estrogen on Bone
Estrogen –/ apoptosis in bone forming osteoblasts and induces apoptosis in bone-resorbing osteoclasts
Achondroplasia What is it? PathoPhys Genetics Presentation
Failure of longitudinal bone growth (endochondral ossification) –> short limbs. Membranous ossification not affected –> Large head relative to limbs.
Constitutive activation of Fibroblast Growth Factor Receptor 3 (FGFR3) inhibits chondrocyte proliferation
More than 85% of mutations are sporadic and associated with advanced paternal age. Condition also shows Autosomal Dominant inheritance
Dwarfism. Normal lifespan and fertility
Osteoporosis
What is it?
Lab Values
What can in lead to?
Trabecular (spongy) bone loses mass and interconnections despite normal bone mineralization
Normal lab values (serum Ca and PO4)
Vertebral Crush Fractures (Acute back pain, Loss of height, Kyphosis)
Osteoporosis Type 1
Context
PathoPhys
Areas affected
Postmenopausal
↑ bone resorption due to ↓ estrogen
Femoral neck fracture, distal radius (Colles’ fracture)
Osteoporosis Type 2 Context Prophylaxis Treatment Contraindications
Men and Women > 70 years old
Regular weight bearing exercise, Ca and Vit D intake
SERMs (estrogen) +/or Calcitonin, Bisphosphonates or pulsatile PTH for severe cases
Glucocorticoids are contraindicated
Osteopetrosis AKA PathoPhys Description of bones Consequences of bone pathology?
Marble Bone Disease
Failure of normal bone resorption due to defective osteoclasts. Mutations (Carbonic Anhydrase II) impairs ability of osteoclasts to generate acidic environment necessary for bone resorption
Thickened, dense bones that are prone to fracture.
Bone fills marrow space causing pancytopenia, extramedullary hematopoiesis
Osteopetrosis
XR
Complications
Treatment
Bone-in-bone appearance
Cranial nerve impingement and palsies b/c of narrow foramina
Bone marrow transplant because osteoclasts derived from monocytes
Osteomalacia/Rickets
Population affected
PathoPhys
Findings
Adults: Osteomalacia, Children: Rickets
Defective mineralization/calcification of osteoid. ↓ VitD –> ↓ serum Ca –> ↑ PTH –> ↓ serum Phosphate
Hyperactive osteoblasts –> ↑ AlkPhos (osteoblasts require alkaline environment)
Paget's Disease of Bone AKA Frequency PathoPhys Findings Description of bone Fractures? Complications Presentation
Osteitis Deformans
Common
Localized bone remodeling disorder causes by ↑ in osteoblasts and osteoclasts
Serum Ca, PO4, and PTH normal. ↑ ALP
Mosaic (woven) bone pattern
Long bone chalk-stick fractures
↑ blood flow from ↑ arteriovenous shunts –> high output heart failure
↑ risk of osteogenic sarcoma
Hat size ↑, hearing loss (auditory foramen narrowing)
Osteoporosis Serum Ca Serum PO4 ALP PTH Bone description
- - - - ↓ Bone Mass
Osteopetrosis Serum Ca Serum PO4 ALP PTH Bone description
↓Ca No change in PO4 ↑ ALP No change in PTH Thickened, dense bones
Osteomalacia/Rickets Serum Ca Serum PO4 ALP PTH Bone description
↓ Ca ↓ PO4 ↑ ALP ↑ PTH Soft Bones
Osteitis Fibrosa Cystica Serum Ca Serum PO4 ALP PTH Bone description
↑ Ca ↓ PO4 ↑ ALP ↑ PTH "Bone tumors" of hyperparathyroidism
Paget's Disease Serum Ca Serum PO4 ALP PTH Bone description
No change in Ca No change in PO4 ↑ ALP No change in PTH Abnormal bone architecture
Polyostotic Fibrous Dysplasia
PathoPhys
Name of a form of it?
Bone replaced by fibroblasts, collagen, and irregular bony trabeculae
McCune-Albright Syndrome characterized by multiple unilateral bone lesions associated with endocrine abnormalities (precocious puberty) and cafe-au-lait spots
Giant Cell Tumor of Bone Name Epidemiology Location Malignant? XR Histo
Osteoclastoma
20-40 year olds
Epiphyseal end of long bones: distal femur, proximal tibial region (knee)
Locally aggressive benign tumor
Double bubble or soap bubble appearance
Spindle-shaped cells with multinucleated giant cells
Osteochondroma Name Frequency Epidemiology Location Description Malignant?
Exostosis Most common benign tumor Males < 25 Originates from long Metaphysis Mature bone w/ cartilaginous cap Malignant transformation into chondrosacroma is rare
Osteosarcoma Name Frequency Epidemiology Prognosis Treatment
Osteogenic sarcoma
2nd most common primary malignant bone tumor (after multiple myeloma)
Male > female, 10-20 years old
Aggressive
Surgical en bloc resection (with limb salvage) and chemotherapy
Metaphysis
Wider portin of long bone adjacent to epiphyseal plate
Osteosarcoma
Predisposing factors
Location
XR
Paget’s disease of bone, Bone infarcts, Radiation, Familial Retinoblastoma
Metaphysis of long bone often around distal femur and proximal tibial region (knee)
Codman’s Triangle (from elevation of periosteum) or sunburnt pattern
Ewing's Sarcoma Epidemiology Location Histo Malignant?
Boys < 15 years old
Diaphysis of long bones, pelvis, scapula, and ribs
Anaplastic small blue cell tumor
Malignant
Ewing's Sarcoma XR Genetics Prognosis Treatment
Onion skin appearance in bone
t(11;22) translocation
Extremely aggressive with early mets
Responsive to chemotherapy
Chondrosarcoma Epidemiology Location Malignant Type of tissue? Origin? Gross
Men 30 - 60
Diaphysis. Pelvis, Spine, Scapula, Humerus, Tibia, Femur
Malignant
Cartilaginous
Primary or from osteochondroma
Expansive glistening mass within medullary cavity
Osteoarthritis
Etiology
Predisposing factors
Treatment
Mechanical (wear and tear) destruction of articular cartilage
Age, Obesity, Joint deformity
NSAIDs, Intra-articular glucocorticoids
Osteoarthritis
Presentation
XR
Gross
Pain in weight-bearing joints after use (at end of day), Improves with rest, Knee cartilage loss begins medially (bowlegged), No systemic symptoms, Not inflammatory
Subchondral cysts, Sclerosis, Joint narrowing, Osteophytes (bone spurs)
Eburnation (polished, ivory like appearance of bone), Ulcerated cartilage, Thickened capsule, Synovial hypertrophy, Bouchard’s nodes (PIP), No MCP involvement
Rheumatoid Arthritis Etiology Histo Gross Regions involved
Autoimmune - inflammatory destruction of synovial joints. Type III hypersensitivity reaction
Pannus formation in joints (MCP and PIP), Increased synovial fluid, Bone and Cartilage erosion
Subcutaneous rheumatoid nodules (fibrinoid necrosis), Ulnar deviation in fingers, Subluxation, Baker’s Cyst (in popliteal fossa)
MCP and PIP, No DIP
Rheumatoid Arthritis Epidemiology Labs HLA Presentation Treatment
Females > Males
80% have RF+ (anti IgG Ab), Anti-cyclic citrullinated peptide Ab (specific)
HLA-DR4
Morning stiffness lasting >30 minutes and improving with use. Systemic joint involvement and systemic symptoms (fever, fatigue, pleuritis, pericarditis)
NSAIDs, Glucocorticoids, Disease modifying agents (Methotrexate, Sulfasalazine, TNFα inhibitors)
Sjogren's Syndrome PathoPhys Locations Classic Presentation Risks Labs Epidemiology Associated with what other disease?
Lymphocytic infiltration of exocrine glands
Especially lacrimal and salivary glands
Xerophthalmia (dry eyes, conjunctivitis, “sand in my eyes”), Xerostomia (dry mouth, dysphagia), Arthritis, Parotid enlargement
Risk of B cell lymphoma, dental caries
Auto Abs to ribonucleoprotein antigens: SS-A (Ro), SS-B (La)
Females between 40 and 60
Rheumatoid Arthritis
Gout PathoPhys Causes Epidemiology Crystals
Precipitation of monosodium Urate Crystals into joints due to hyperuricemia
Lesch-Nyhan syndrome, PRPP excess, ↓ excretion of uric acid (thiazide diuretics), ↑ cell turnover, von Gierke’s disease. 90% due to underexcretion, 10% due to overproduction.
More common in men
Crystals are needle shaped and negatively birefringent (yellow crystals under parallel light)
Gout Distribution Description of joints Classic manifestation Gross signs When does it present?
Asymmetric joint distribution Joints are swollen, red, and painful Painful MTP (metatarsophalangeal) joint of the big toe (podagra) Tophus formation (external ear, olecranon bursa, achilles tendon) Acute attacks tend to occur after a large meal or EtOH consumption
Why does EtOH aggravate Gout
EtOH metabolites compete for same excretion sites in kidney as uric acid causing ↓ uric acid secretion
Pseudogout What causes it? Histo Which joints affected? Epidemiology Treatment
Deposition of Ca pyrophosphate crystals w/in joint space
Basophilic rhomboid crystals that are weakly positively birefringent
Large joints (knee)
Older than 50, male and female equal
NSAIDs (sudden severe attacks), Steroids, Colchicine
Crystals in Gout vs Pseudogout
Gout: yellow when parallel to light
Pseudogout: blue when parallel to light
Infectious Arthritis
Causative agents
Presentation
S. aureus, Streptococcus, Neisseria gonorrhoeae
Joints are swollen, painful, and red
“STD”
Synovitis (knee), Tenosynovitis (hand), Dermatitis (pustules)
Gonoccal Arthritis
STD that presents as a migratory arthritis with an asymmetric pattern
Osteonecrosis Name What happens? Presentation What causes it? Most common site?
Avascular necrosis Infarction of bone and marrow Pain associated with activity Trauma, high-dose corticosteroids, alcoholism, sickle cell Femoral head
Seronegative Spondyloarthropathies What are they? HLA Epidemiology Names
Arthritis w/o RF HLAB27 Males "PAIR" Psoriatic arthritis, Ankylosing spondylitis, IBD, Reactive arthritis
Psoriatic Arthritis What is it? Distribution Gross XR % of pts with psoriasis that get it?
Joint pain and stiffness associated with psoriasis Asymmetric and patchy involvement Dactylitis (sausage fingers) Pencil in cup deformity on XR 1/3 of pts with psoriasis get it
Ankylosing Spondylitis
What is it? Where is it?
Presentation
XR
Chronic inflammatory disease of spine and sacroiliac joints Ankylosis (stiff spine due to fusion of joints), Uveitis, Aortic Regurgitation Bamboo spine (vertebral fusion)
Reactive Arthritis
Name
Presentation
Causes
Reiter’s Syndrome
“Can’t see, Can’t Pee, Can’t Climb a Tree”
Conjunctivitis and anterior uveitis, Urethritis, Arthritis, Palm and Sole Rash
Post GI or Chlamydia infection
Polymyalgia Rheumatica Symptoms Epidemiology Associated with what other diseases? Labs Treatment
Pain and stiffness in shoulders and hips often with fever, malaise, and wt loss. Does not cause muscular weakness
More common in women > 50
Associated with Temporal Giant Cell Arteritis
↑ ESR. Normal CK
Rapid response to low-dose corticosteroids
Fibromyalgia
Epidemiology
Presentation
Secondary symptoms
Women 20-50
Chronic, widespread musculoskeletal pain
Associated with stiffness, paresthesia, poor sleep, and fatigue
Polymyositis Presentation Histo Common location Findings Treatment
Progressive symmetric proximal muscle weakness
Endomysial inflammation with CD8+ T cells
Shoulders
↑ CK, ANA+, +anti Jo1 Abs
Steroids
Dermatomyositis Presentation Histo Risks Findings Treatment
Progressive symmetric proximal muscle weakness with malar rash, Gottron’s papules, Heliotrope rash, Shawl and Face rash, Mechanic hands
Perimysial inflammation and atrophy with CD4+ T cells
↑ risk of occult malignancy
↑ CK, ANA+, +anti Jo1 Abs
Steroids
Names of Neuromuscular Junction Diseases
Myasthenia gravis
Lambert-Eaton Myasthenic Syndrome
Myasthenia gravis Frequency Pathophysiology Presentation Associated w/ Treatment
Most common NMJ disorder AutoAbs to postsynaptic ACh receptors Ptosis, Diplopia, Weakness, Worsens with muscle use Thymoma, Thymic hyperplasia AChE inhibitors
Lambert-Eaton Myasthenic Syndrome Frequency Pathophysiology Presentation Associated w/ Treatment
Uncommon
AutoAbs to presynaptic Ca channels –> ACh release
Proximal muscle weakness that improves with muscle use
Small cell lung cancer
No effect with AChE inhibitors
Myositis Ossificans
What is it?
Location
Presentation
Metaplasia of skeletal muscle to bone following muscular trauma
Most often seen in upper and lower extremity
May present as suspicious mass at site of known trauma or as incidental finding on radiography
Lipoxygenase pathway yields…
Leukotrienes
LTB4
“Neutrophils Arrive Before Others”
Neutrophil chemotactic
LTC4, D4, and E4
Bronchoconstriction, Vasoconstriction, Contraction of Smooth Muscle, ↑ Vascular permeability
PGI2
Name
Function
Synthesis
Prostacyclin
“Platelet Gathering Inhibitor”
Inhibits platelet aggregation and promotes vasodilation. ↓ Bronchial tone, ↓ Uterine tone
Membrane lipids (eg phosphatidylinositol) –> [PLA2] –> Arachidonic Acid –> [COX] –> Endoperoxides (PGG2, PGH2) –> Prostacyclin (PGI2)
Leukotriene Synthesis
Membrane lipids (eg phosphatidylinositol) –> [PLA2] –> Arachidonic Acid –> [Lipoxygenase] –> Hydroperoxides (HPETEs) –> Leukotrienes
Prostaglandins
Names
Function
Synthesis
PGE2, PGF2α
↑ Uterine tone, ↓ Vascular tone, ↓ Bronchial tone
Membrane lipids (eg phosphatidylinositol) –> [PLA2] –> Arachidonic Acid –> [COX] –> Endoperoxides (PGG2, PGH2) –> Prostaglandins
Thromboxane
Names
Function
Synthesis
TXA2
↑ Platelet aggregation, ↑ Vascular tone, ↑ Bronchial tone
Membrane lipids (eg phosphatidylinositol) –> [PLA2] –> Arachidonic Acid –> [COX] –> Endoperoxides (PGG2, PGH2) –> Thromboxane
Aspirin
Mechanism
Net result
Class
Irreversibly inhibits COX1 and COX2 by acetylation
↓ synthesis of both TXA2 and Prostaglandins, ↑ bleeding time, No effect on PT of PTT
NSAID
Aspirin
Uses
Tox
Low dose (less than 300mg): ↓ platelet aggregation. Intermediate dose (300-2400): antipyretic and analgesic. High dose (2400-4000): anti-inflammatory Gastric ulcers, Tinnitus (CNVIII), Chronci use can lead to acute renal failure, interstitial nephritis, upper GI bleed. Reyes syndrome in children. Stimulates respiratory centers leading to hyperventilation and respiratory alkalosis
NSAIDs Names Mechanism Use Tox
Ibuprofen, Naproxen, Indomethacin, Ketorolac, Diclofenac
Reversibly inhibits COX1 and COX2. Blocks Prostaglandin synthesis
Antipyretic, analgesic, anti-inflammatory. Indomethacin used to close PDA
Interstitial nephritis, Gastric ulcer, Renal ischemia
COX2 Inhibitors
Name
MoA
What does it Spare?
Celecoxib
Reversibly inhibits COX2 which is found in inflammatory cells and vascular endothelium and mediates inflammation and pain.
Spares COX1 and thus doesn’t affect gastric mucosa. Also spares TXA2 and spares platelet function
COX2 Inhibitors
Use
Tox
RA and Osteoarthritis in pts with gastritis or ulcers
↑ risk of thrombosis. Sulfa allergy
Acetaminophen
MoA
Use
Tox
Reversibly inhibits COX, mostly in CNS. Inactivated peripherally
Antipyretic, analgesic, not anti-inflammatory. Used instead of aspirin to avoid Reyes Syndrome in children w/ viral infection
OD produces hepatic necrosis. Metabolite depletes glutathione and forms toxic tissue adducts in liver
Cure for Acetaminophen OD
N-acetylcysteine regenerates Glutathione
Bisphosphonates Names Kind of drug MoA Use Tox
Alendronate, other -dronates
Pyrophosphate analog
Bind hydroxyapatite in bone and inhibits osteoclast activity
Osteoporosis, hyperCa, Paget’s disease of bone
Corrosive esophagitis, Osteonecrosis of the jaw
Names of Gout Drugs
Allopurinol, Febuxostat, Probenecid, Colchicine
Allopurinol MoA Use Findings w/ use What drugs cannot go with it? Affect on uric acid clearance?
Inhibits xanthine oxidase thus ↓ conversion of xanthine to uric acid
Gout, Lymphoma and Leukemia (to prevent tumor lysis and associated urate nephropathy).
↑ concentrations of azathioprine and 6MP (both normally metabolized by xanthine oxidase)
Do not give salicylates
All but highest doses depress uric acid clearance. Even high doses have only minor uricosuric activity
Febuxostat
MoA
Use
Inhibits xanthine oxidase
Gout
Probenecid
MoA
Use
Tox
Inhibits reabsorption of uric acid in PCT
Gout
inhibits secretion of penicillin
Colchicine
MoA
Use
Tox
Binds and stabilizes tubulin to inhibit polymerization thus impairing leukocyte chemotaxis and degranulation (decreases LTB4)
Gout
GI side effects, especially if given orally: diarrhea, abdominal pain, nausea
Myelosuppression
Acute drugs for gout
NSAIDs (Naproxen and Indomethacin)
Oral or Intramuscular Glucocorticoids
Risks of TNFα inhibitors
Predispose to infection including TB since TNF blockade prevents activation of macrophages and destruction of phagocytosed microbes
Etanercept Class of drug Description of drug MoA Use
“etanerCEPT is a TNF decoy reCEPTor”
TNFα inhibitors
Fusion protein: receptor for TNFα and IgG1 Fc produced by recombinant DNA
RA, Psoriasis, Ankylosing Spondylitis
Infliximab, Adalimumab
Class of drug
MoA
Use
TNFα inhibitors
Anti TNFα monoclonal Ab
RA, Psoriasis, Ankylosing Spondylitis, Crohn’s Disease
Periosteum
A membrane that lines the outer surface of all bones, except at the joints of long bones.
Osteoid
Unmineralized bone
Bones of lateral foot
Posterior to anterior: Calcaneus and Cuboid
Bones of medial foot
Posterior to anterior: Talus and Navicular bones
Medial, Intermediate, and Lateral Cuneiforms
Sensory innervation of anterior leg
Deep Peroneal nerve: In between big toe and 2nd toe
Superficial Peroneal nerve: Top of foot and Lateral Leg
Sural Nerve: Lateral foot
Saphenous nerve (L3-L4): Medial leg and medial knee
Femoral nerve: Anterior and lateral thigh
Obturator nerve: Medial thigh
Sensory innervation of posterior leg
Tibial nerve: plantar surface of foot Sural nerve: lateral leg Saphenous nerve: Medial leg Femoral nerve: Lateral thigh Sciatic nerve: Posterior thigh