Placing a lateral pressure at the knee is testing what?
Medial collateral ligament strength.
Increased stretching on the medial side indicates damage.
Placing a medial pressure at the knee is testing what?
Tests for lateral collateral ligament strength.
Increased stretching laterally will indicate damage.
What is the McMurray’s test checking?
Internally and externally rotating the leg during range of motion.
Popping on external rotation indicates a medial meniscal tear.
Popping on internal rotation indicates a lateral meniscal tear.
What is the unhappy triad?
Medial meniscal tear
Medial collateral ligament
Anterior cruciate ligament.
It should be known though that lateral meniscus injury is more common.
What are the rotator cuff muscles?
SItS Supraspinatous Infraspinatius Teres minor Subscapularis
Which muscle of the rotator cuff is most commonly damaged?
Supraspinatus (suprascapular nerve)
Tested by the empty/full can test.
abducts the arm before the deltoids kick in.
What rotator cuff is commonly injured in a pitching injury?
Infraspinatus (suprascapular nerve)
Muscle is responsible for laterally rotating the arm.
What is the action of teres minor?
Axillary nerve
Adducts and laterally rotates the arm.
What is the action of subscapularis?
Upper and lower subscapular nerves
Medially rotates and adducts the arm.
Innervated mostly by C5 and C6( entire rotator cuff)
Golfers elbow
Medial epicondylitis of the arm
Repetitive flexion
Tennis elbow
Lateral epicondylitis
Repetitive extension
Most commonly injure carpal bone that is also prone to avascular necrosis?
Scaphoid bone.
Also known as the snuff box.
It is suceptible because of its retrograde blood supply.
Dislocation of which carpal bone can cause severe carpal tunnel?
Dislocation of the lunate bone.
The hook of which carpal bone can cause ulnar compression if damaged?
The hook of the hamate.
Nerve damaged with fractured surgical neck of the humerus or anterior dislocation of the humerus?
Axillary nerve
Upper trunk compression leads to damage of what nerve?
Musculocutaneous
C5-C7
Midshaft fracture of the humerus or saturday night palsey/walking in crutches.
Radial nerve injury.
C5-T1
What nerve is injured with a supracondylar fracture of the humerus?
Median nerve
C5-T1
Can be proximal (in humerus) or distal (carpal tunnel)
Will effect the hand differently.
Medial epicondyle of the humerus fractures effect what…?
Ulnar nerve C8-T1
Can ead to different problems if proximal compared to distal.
Damage to the recurrent branch of the median nerve leads to what disorder?
C5-T1 injury can occur with superficial palm lacerations.
Will present with popes hand as the thenar muscle group will be damaged.
Describe Erbs palsy
Destruction/damage of the upper trunk C5-C6 roots
Leads to waiters tip sign (loss of flexors)
Lateral traction on an infants neck when born
Erbs palsey
Damage to C5-C6 waiters tip
Arm dangling to side, fully extended, medially rotated and hand flexed/supinated
Grabbing a tree branch to break a fall
Damage of the C8-T1 nerve roots.
Leads to Klumpke palsey –> Loss of internal hand muscles.
“Total Claw hand”
How would a pancoast tumor/ thoracic outlet syndrome present?
Same as Klumpsky as the lower roots would be damaged.
What could possibly lead to long thoracic nerve damage
Would result in a winged scapula and would be seen after a masectomy when removing lymph nodes.
Seratus anterior wont be working correctly.
Describe the general pattern following proximal vs distal nerve injury in the arm.
Proximal injuries generally present with difficulty flexing and extinding all of the fingers.
Distal injuries generally cause clawing.
How would damage to the superior gluteal nerve compare to the inferior gluteal nerve in prsentation?
Superior gluteal nerve would present with lack of abduction while standing “trendelenberg sign”
Inferior gluteal nerve would present with difficutly standing from a sitting position (loss of hip extension)
Damage to which nerve would result in the inability to stand on your tip toes?
Damage to the tibial nerve.
what artery correlates to damage to the surgical neck of the humerus?
Posterior circumflex
What artery correlates to damage to the midshaft of teh humerus?
Deep brachial
What artery correlates to damage to the distal humerus/cubital fossa?
Brachial artery
Depolarization of voltage sensitive …. receptors leads to calcium release from the sarcoplasmic reticulum.
Depolarization of the voltage sensitive dihydropyridine receptor mechanically coupled to the ryanodine receptor in muscle cells.
Contraction of muscle leads to shortening of which muscle bands?
H and I muscle bands between Z lines.
“HIZ Shrinkage”
A band is always the same length!!!
What change results in the myosin head becoming “Cocked”
ATP binding releases the myosin head from the actin filament and is hydrolyzed to ADP coking the head for the next contraction cycle.
How does smooth muscle contract?
Depolarization leads to L-type calcium channels opening.
Calcium influx increases the myosin-light chain kinase activity leading to myosin and actin binding and contracting.
How does nitric oxide effect smooth muscle?
Activates Guanylate cyclase “cGMP” leading to myosin light chain phosphatase activation.
This stops the myosin actin cycle.
Describe endochondral ossification
Bones of the axial and appendicular skeleton/base of skull
Chondroblasts lay down a cartilage model that is then replaced by osteoblasts “woven bone”
Woven bone is then replaced by lamellar bone.
When is woven bone present in adults?
After fractures and pagets disease.
Achondroplasia
Failure of longitudinal bone growth by endochondral ossification. Membranous ossification (skull and face) is not effected.
Typically because of excessive fibroblast growth factor receptor inhibiting chondrocyte proliferation.
What type of bone is lost in primary osteoporosis?
Loss of trabecular bone mass.
DEXA score of
What are the four drug classes that can cause osteoperosis?
Anticoagulants
Thyroid Replacement
Anticonvulsants
Long term steroid use
Look for vertebral compression fractures.
How does estrogen work in the bones?
Stops apoptosis of osteoblasts and promotes apoptosis of osteoclasts.
Osteopetrosis
Failure to reabsorb bone due to defective osteoclasts
Osteomalacia/rickets
Vitamin D deficiency
Thus cannot calcify bone/osteoid
Alkaline phosphate will be increased as well as osteoblasts require alkaline environment to try and work in.
What is the classic 4 presentations of seronegative spondyloarthropies?
HLA-B27 in men
Psoriatic arthritis “Pencil and cup”
Ankylosing Spondylitis (spine and Sacroiliac joints)
Inflammatory Bowel disease
Reactive arthritis (cant see cant pee etc)
Libman sacks endocarditis
Vegatative non bacterial frowths on heart valve associated with systemic lupus erythematous
Elevated serum ACE in black female with enlarged lymph nodes
Suspect sarcoidosis.
Look for restrictive lung diseases or bells palsy.
treat with steroids.
Temporal or giant cell arteritis is commonly related to which condition?
Polymyalgia rheumatica.
Ptsosis, diplopia, weakness that worsens with muscle use is likely?
Myasthenia gravis
Autoantibodies directed at postsynaptic ACh receptors.
What is the underlying problem with lambert-eaton myasthenic syndome?
Autoantibodies to presynaptic calcium channel decreasing ACh release
Proximal muscle weakness, autonomic symptoms of dry mouth and impotense that improves with muscle use is a sign of?
Lambert eaton myasthnia syndrome.
Triad of autoimmunity, noninflammatory vasculopathy, collagen deposition with fibrosis.
Scleroderma
epidermal Skin layers from the surface to the base***
Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale
Californians Like Girls in String Bikinis
Bullous pemphigoid
Connects keratin in basal cells to underlying basement membrane.
Cadherins vs integrins
Cadhering maintain cell to cell interactions through adherens.
Integrins maintain the connection of cells to the basement membrane
Albinism
Normal ammount of melanocytes
Decreased/defective tyrosinase activity.
Vitiligo
Autoimmune destruction of melanocytes.
Think black person gaining white skin.
Cellulitis vs erysipelas
Cellulitis has spreading borders erisypelas does not.
Nikolskys sign
Separation of epidermis upon manual stroking of the skin.
Seen with pemphigus vulgaris IgG antibody against desmoglien.
Bullous pemphigoid vs pemphigus vulgaris
In bullous pemphigoid IgG is directed against hemidesmasomes and wont have nikolskys sign.
Pemphigus vulgaris is way worse and has IgG against desmoglien.
Most common skin cancer
Basal cell carcinoma
Look for the palisading nucei
Skin cancer common with sun exposure
Squamous cell carcinoma
Keratin pearls
Actinic keratosis
Scaly plaque precursor to squamous cell carcinoma