Flashcards in Musculoskeletal Deck (119)
MCL, ACL, Medial meniscus
The term anterior and posterior in ACL and PCL refer to what?
Where they attach to the tibia
If looking down on the tibia where would we see the PCL attaching?
Posterior pretty much in the dead center
Between the ACL and PCL, which stays mostly in the midline and which sweeps side to side?
PCL is more confined to the midline, ACL goes from lateral (superior) to medial (inferior)
Bones of the hand (include position)
(proximal thumb side) Scaphoid, Lunate, Triquetrum, Pisiform (proximal pinkie side). (Distal thumb side) Trapezium, Trapezoid, Capitate, Hammate (distal pinkie side)
What nerve is compressed by incorrect use of crutches?
What does the lower trunk of the brachial plexus innervate and what is the consequence of this?
All intrinsic muscles of the hand. Damage leads to hand clumsiness
Damage to which nerve leads to wrist drop?
Damage to what structure leads to waiters tip (Erbs Palsy)?
Upper trunk of brachial plexus
What structures will likely be damage by the following injuries: fracture of surgical neck of humerus, dislocation of humeral head, fracture of midshaft humerus
Surgical neck - axillary nerve, humeral head - axillary nerve, midshaft - radial nerve
What structures will likely be damaged by the following injuries: fracture of supracondylar humerus, dislocated lunate, fracture of medial epicondyle of humerus, fracture of hook of hamate, and upper trunk compression
Supracondylar humerus - median (prox), lunate - median (dist), medial epicondyle of humerus - ulnar (prox), hook of hamate (ulnar - dist), upper trunk - musculocutaneous
If you have a fracture at midshaft of the humerus, what two structures are at risk?
Radial nerve and deep brachial artery
Causes of carpal tunnel
Repetitive stress (most common), fluid retention (renal failure, hypothyroid, pregnancy), DM, RA, dialysis-associated amyloidosis
Course of the median nerve
Between humeral and ulnar heads of pronator teres then between flexor digitorum superficials and flexor digitorum profundus, then enters carpal tunnel
Complications of mastectomy
Winged scapula (serratus anterior, LTN), lymphedema, inability to abduct shoulder past 90 degrees (serratus anterior, LTN)
Nerve responsible for thigh adduction
Contralateral hip drops when standing on leg ipsilateral to lesion. Problem with superior gluteal nerve (L4-S1)
Where should you give butt injections?
Superolaterally. Superomedial quadrant endangers superior gluteal nerve (may get trendelenburg sign)
Sciatica in posterior thigh with diminished ankle reflex
Compression of S1
Which is the thin filament and which the thick?
Actin is thin filament (lighter), myosin is thick (darker)
What system in skeletal muscle ensures coordinated contraction of myofibrils?
Type 1 and Type 2 muscle
1 - slow twitch, red. 2 - Fast twitch, white
Short limbs with a normal spine
Short limbs with a short spine
GH or IGF-1 mutation
Histology of osteoporosis
Trabecular thinning with fewer interconnections
Histology of osteopetrosis
Spongiosa filling medullary canals with no mature trabeculae
Which type of osteoporosis is post menopausal?
Histology of osteomalacia/rickets
Osteoid matrix accumulation around trabeculae
Bony prominance at costochondral junctions with bowed legs
Rickets (prominences are called rosary chest)
Histology of Pagets disease of bone
Lamellar bone structure resembling a mosaic
Complications of Pagets disease of bone
Hearing loss (auditory foramen narrowing), increased hat size
Genetic deficiency and labs in osteopetrosis
Deficiency of carbonic anhydrase 2. Calcium, phosphate, and alk phos are normal. Anemia, thrombocytopenia, infection, extramedullary hematopoiesis
Lab values in Pagets disease of bone
Normal except Alk Phos, which is high
Appearance of osteitis fibrosa cystica
Marker for Pagets disease of bone
High Alk Phos with (sometimes) TRAP positivity
Polyostotic fibrous dysplasia. Multiple unilateral bone lesions with endocrine abnormalities (precocious puberty) and cafe-au-lait spots. Bone replaced by fibroblasts, collagen, and irregular bony trabeculae
Age, location, and predisposing factors in osteosarcoma
Males ages 10-20. Metaphysis of long bones (femur, proximal tibia). Associated with Pagets, bone infarcts, radiation, and familial Rb
What causes Codmans triangle (sunburst pattern) in osteosarcoma?
Elevation of periosteum
Translocation in Ewings sarcoma
Onion skin appearance in bone
Bone tumors by location and malignant status
Epiphysis - Giant cell tumor (benign). Metaphysis - Osteochondroma (benign) and Osteosarcoma (malignant). Diaphysis - Chondrosarcoma (malignant), and Ewings sarcoma (malignant)
Where are Heberdens nodes and Bouchards nodes and what disease are they associated with?
OA. Heberden - DIP, Bouchard (PIP)
NSAIDs, COX-2 inhibitors, glucocorticoids (short term), DMARDS (MTX, Sulfasalazine, hydroxychloroquine, TNF-a inhibitors)
Autoantibodies in Sjogrens
SS-A and SS-B
Birefringence of gout and pseudogout
Gout - negative, Pseudogout - weakly positive
Precipitants of gout
Lesch-Nyhan, PRPP excess, decreased excretion (eg thiazides), increased cell turnover, von-Gierkes disease
Give the color of crystals in gout and pseudogout
Gout - yellow when parallel, blue when perpendicular. Pseudogout - yellow when perpendicular, blue when parallel
Crystals in pseudogout
Causes of infectious arthritis
Septic - s aureus, streptococcus, n gonorrhoeae. Chronic - TB, lyme
Causes of osteonecrosis (avascular necrosis)
Trauma, high dose corticosteroids, alcoholism, sickle cell
Psoriatic arthritis, Ankylosing spondylitis, Inflammatory bowel disease associated spondylitis, Reactive (Reiters) arthritis
Where is inflammation common in akylosing spondylitis and what is the consequence of this?
Sites of tendon insertion. May lead to reduce chest expansion and hyperventilation
Presentation of Reiters syndrome
Conjunctivitis with anterior uveitis, urethritis, arthritis and sacroilitis. Cant see cant pee cant climb a tree
SLE is associated with antiphospholipid antibodies. What is the clinical consequence of these?
Venous and arterial thromboemboli. Also recurrent miscarriages (which is how SLE may present)
Common antibodies in SLE
Anti-dsDNA, anti-smith, antiphospholipid
What is the accuracy of ANA in SLE?
Sensitive but not specific
Which antibody in SLE is most prognostic?
Anti-double stranded DNA. Indicates poor prognosis (anti-smith is specific but not prognostic)
Antibodies associated with drug induced lupus
Restrictive lung disease, hilar lymphadenopathy, erythema nodosum, Bells palsy, uveoparotitis, hypercalcemia, elevated ACE levels
Treatment for sarcoid
Lab findings and treatment for polymyalgia rheumatica
Elevated ESR with normal CK. Treat with prednisone
What disorder besides SLE includes a malar rash
Findings in dermato and polymyositis
High CK, high Aldolase, positive ANA and positive anti-jo-1
Finger ulceration and telangiectasias in a woman
What causes the esophageal dysmotility of CREST syndrome?
Fibrous replacement of the muscularis
Antibodies in diffuse scleroderma and CREST syndrome respectively
Diffuse scleroderma - SCL-70 antibody (which is anti-DNA topoisomerase 1). CREST - anti-centromere antibody
Calcinosis (and anti-centromere), Raynauds, Esophageal dysmotility, Sclerodactyly, Telangiectasia
Which has a worse prognosis, diffuse scleroderma or CREST?
Histologic appearance of warts
Epidermal hyperplasia, hyperkeratosis, koilocytosis
Common mole. Benign
Eczema location, triggers, and histology
Skin flexures. May be triggered by foods or other environmental factors. Will see spongiosis on microscopy
Psoriasis location, and histology
Knees and elbows. Acanthosis with parakeratotic scaling (nuclei in cornuem). Increased spinosum, decreased granulosum, occasional neutrophils
Irregular areas of complete depigmentation. Caused by a decrease in melanocytes
Infectious organisms of impetigo and potential results of the infection
S aureus or strep pyogenous. May result in rheumatic fever or post-strep GN
What does PABA sunscreen block?
UVB (but not UVA)
IgG against desmosomes (3 and 1). Positive Nikolskys sign
IgG against hemidesmosomes (epidermal basement membrane). Negative Nikolskys sign. Does not affect oral mucosa (unlike pemphigus vulgaris)
Histology of actinic keratoses
Hyperkeratosis, parakeratosis, basal cell layer atypia. Risk of carcinoma is proportional level of dysplasia
Mutation in melanoma
BRAF mutation in 40 to 60 percent
What do prostaglandins and prostacyclins respectively do to uterine tone?
Prostaglandins increase uterine tone, prostacyclin decreases uterine tone
What is the only LOX related drug approved for asthma in young kids?
How big is COX-2 and when is it detectable?
72 KD. Only expressed during inflammation (COX-1 is constitutively expressed)
List the NSAIDs (4)
Ibuprofen, naproxen, indomethacin, ketorolac
Toxicities of NSAIDs
Renal damage, fluid retention, aplastic anemia, GI distress, ulcers
What effect does celecoxib have on platelet aggregation?
None. It is anti-inflammatory without impairing platelet function
What drug is used to prevent recurrence of colonic adenocarcinoma?
COX-2 inhibitors (may decrease adenomtaous polyp formation)
Reversibly inhibits COX (mostly in CNS). Not anti-inflammatory. Use to avoid Reyes syndrome. N-acetylcysteine is antidote
List the bisphosphonates (5)
Etidronate, pamidronate, alendronate, risedronate, zoledronate (IV)
Mechanism of bisphosphonates
Inhibit osteoclastic activity
Uses and toxicities of bisphosphonates
Malignancy-associated hypercalcemia, Pagets disease, postmenopausal osteoporosis. Corrosive esophagitis, nausea, diarrhea, osteonecrosis of jaw
Mechanism of Probenacid, Allopurinol, Febuxostat
Probenecid - inhibits reabsorption of uric acid in PCT. Allopurinol and febuxostat inhibit xanthine oxidase
What should you not give with allopurinol?
Salicylates (all but highest doses depress uric acid clearance)
Mechanism of colchicine
Stabilizes tubulin, impairing leukocyte chemotaxis and degranulation
TNF-a inhibitor. Use in RA, psoriasis, AS
Anti-TNF antibody. Use in Crohns, RA, AS
Anti-TNF antibody. Use in RA, psoriasis, AS
Complication of TNF-a inhibitor therapy
Infection, especially reactivation of TB
What structure may be damaged in a femoral neck injury
Medial circumflex artery
What type of antibody is Rh factor?
IgM against IgG
In which condition do you get fixing of the joint, RA or OA?
Why does alcohol make gout worse?
Metabolic acidosis. Uric acid has to compete with lactic acid and keto-acids created by alcohol for excretion
Why are patients with AS often hunched over?
Because they have restrictive lung disease due to limitation of movement
Difference between osteomalacia and osteporosis (besides just degree)
Osteoporosis affects both mineral and organic component, osteomalacia is decreased mineral with normal organic component
Most common benign bone tumor
Most common cause of HCC in children
What is going on in the thymus in MG
Germinal follicles (which is abnormal since B cells shouldnt be in thymus). Removing thymus helps MG. 10-15 percent will develop a thymoma, but B-cell hyperplasia is best answer for this
If you have CREST plus kidney involvement, what is the diagnosis?
Progressive systemic sclerosis. CREST cannot involve the kidneys
Racoon eyes, elevated serum CK, rash over PIP
Dermatomyositis. High association with cancer
Type of hypersensitivity in atopic dermatitis
Cause of seborrheic dermatitis (dandruff)
Most common cause of tinea capitis
All superficial dermatophyte infections besides tinea capitis are due to what?
Rash on butt, oblong with red outside and pale in middle. Negative KOH prep
Pityriasis rosea. Non infectious. 3 days later it will return with rash in christmas tree distribion
Which type of malignant melanoma can african american patients get?
Acrolentiginous (most aggressive, not related to radiation)
Malignant melanoma on the face of an older patient
Lentigo maligna melanoma
Most important prognostic factor in melanoma
Depth of invasion (will not metastasize if less than .76 mm)
Contractures developing over a period of hours
Black widow bite (look for history of being in a basement or area which might have spiders)