MSK Flashcards
(120 cards)
1
Q
What are the 6 differential diagnoses for tendinopathy?
A
- Tendon rupture 2. Ligamentous injury 3. Inflammatory arthritis (RA) 4. Fractures (avulsion) 5. Tumors 6. Tenosynovitis
2
Q
What are the common sites for tendonitis?
A
Shoulder (supraspinatus), Biceps (long head), Elbow (extensor tendons/tennis elbow), Ankle (Achilles), Wrist (De Quervain’s, flexor carpi ulnaris)
3
Q
What are 6 differential diagnoses for atraumatic nonseptic bursitis?
A
- Rheumatoid arthritis 2. Pseudogout 3. Ankylosing spondylitis 4. Hypertrophic pulmonary osteoarthropathy 5. Oxalosis 6. Gout
4
Q
What is the most common cause of septic bursitis?
A
Staphylococcus aureus
5
Q
What bursal fluid glucose-to-serum ratio suggests septic bursitis?
A
<50% (less than 50%)
6
Q
What WBC count in bursal fluid is highly suggestive of septic bursitis?
A
> 5000/μL³
7
Q
What are the clinical differences between septic vs aseptic bursitis?
A
Septic: Tenderness (88% vs 36%), Erythema/cellulitis (83% vs 27%), Warmth (84% vs 56%), Fever (38% vs 0%)
8
Q
What are the 4 clinical exam findings in impingement syndrome?
A
- Normal neck exam 2. Subacromial/posterior shoulder tenderness 3. Limited glenohumeral ROM (positive painful arc) 4. Positive specialty tests (Neer, Hawkins-Kennedy)
9
Q
What structures are involved in shoulder impingement syndrome?
A
Subacromial bursa, Rotator cuff, Biceps tendon, Labrum
10
Q
What is the key mechanism in tendinopathy development?
A
Mechanical overload and repetitive microtrauma
11
Q
How long can overuse syndromes take to heal?
A
At least 6 to 12 weeks
12
Q
What antibiotic is used for infected bursitis?
A
Most commonly caused by Staph aureus, so use anti-staphylococcal antibiotics
13
Q
What is the definitive diagnosis method for bursitis?
A
Aspiration of the bursa and evaluation of the fluid
14
Q
What are non-mechanical causes of tendinopathy?
A
Systemic disease manifestations, infectious etiologies, fluoroquinolone use
15
Q
What imaging is rarely indicated in ED for tendinopathy?
A
Emergent imaging (though bedside ultrasound can identify tendon disruption/rupture)
16
Q
What is the initial treatment approach for most tendinopathy?
A
PRICE (Protection, Relative rest, Ice, Medications, Elevation)
17
Q
What appears purulent/serosanguineous in septic bursitis?
A
The bursal fluid aspirate
18
Q
What gram stain and culture results indicate septic bursitis?
A
Positive gram stain and culture for organisms
19
Q
What is the management approach for non-septic bursitis?
A
NSAIDs, RICE, appropriate follow-up
20
Q
When is hospitalization considered for bursitis?
A
Severe local infections, immunosuppressed patients, high fever or systemic toxicity
21
Q
What should you look for in septic bursitis examination?
A
Wound or abrasion overlying the involved bursa
22
Q
What are risk factors for septic bursitis?
A
Diabetes, alcoholism, immunosuppression
23
Q
What is the difference between septic and non-septic bursitis fluid appearance?
A
Septic: Purulent/serosanguineous; Non-septic: Straw colored/serous
24
Q
What WBC count suggests non-septic bursitis?
A
<1000/μL³
25
What are other conditions in the differential for bursitis?
Septic arthritis, osteomyelitis, underlying fracture
26
What are 4 monoarticular arthritis causes?
Septic arthritis, Gout, CPPD/pseudogout, Osteoarthritis
27
What are 4 polyarticular symmetrical arthritis causes?
Rheumatoid arthritis flare, Psoriatic arthritis, Polymyalgia rheumatica, Enteric arthritis
28
What are 4 polyarticular asymmetrical arthritis causes?
Gonococcal arthritis, Lyme arthritis, Acute rheumatic fever, Reactive arthritis
29
What is the normal WBC count in joint aspiration?
200-2000 WBC/mm³
30
What synovial WBC count suggests septic arthritis?
>25,000/mm³ (+LR 2.9), >50,000/mm³ (+LR 7.7), >100,000/mm³ (+LR 28)
31
What percentage of PMN cells suggests septic arthritis?
>90% (+LR 2.7)
32
What is the positive rate for gram stain in septic arthritis?
Only 29-65% positive (negative doesn't rule out septic arthritis)
33
What are the two presentations of gonococcal arthritis?
1. Mono-oligoarticular arthritis 2. Disseminated gonococcal infection (arthritis-dermatitis syndrome with bacteremia, migratory arthralgias, skin lesions, tenosynovitis)
34
What are 4 therapies for acute gout?
1. NSAIDs 2. Colchicine 3. Corticosteroids (intra-articular or systemic) 4. ACTH
35
What is the colchicine dosing for acute gout?
1.2 mg PO, then 0.6 mg PO one hour later, then 0.6 mg PO TID
36
What are risk factors for gout?
Chronic obesity, hypertension, diabetes, thiazide diuretics, cyclosporine, lead exposure, purine-rich diets, high-fructose corn syrup
37
What are the microbiology causes of septic arthritis in neonates/infants?
Staphylococcus aureus, Group B streptococcus, GNR bacteria
38
What causes septic arthritis in adolescents/young adults?
Neisseria gonorrhoeae, Chlamydia trachomatis
39
What causes septic arthritis in older adults?
S. aureus, Streptococcus, GNR bacteria
40
What is the treatment for septic arthritis?
Hospitalization, IV antibiotics, joint drainage. Gram-positive: Vancomycin 30 mg/kg daily. Gram-negative: 3rd generation cephalosporin
41
What are 6 viral arthritides?
Hepatitis B, Hepatitis C, HIV, Parvovirus B19, Rubella virus, Alphaviruses (Ross River, Chikungunya)
42
What are 2 indications for arthrocentesis?
Obtain joint fluid for analysis, Drain tense hemarthrosis
43
What are 2 contraindications for arthrocentesis?
Overlying cellulitis, Coagulopathy/severe bleeding disorder
44
What are 2 complications of arthrocentesis?
Bleeding/infection in joint space, Reaction to anesthetic agents
45
What crystals are seen in gout vs pseudogout?
Gout: Needle-shaped, strongly negatively birefringent urate crystals. Pseudogout: Polymorphic, rhomboid, weakly positively birefringent calcium pyrophosphate crystals
46
What are 5 characteristics of seronegative spondyloarthropathies?
1. Sacroiliac involvement 2. Peripheral inflammatory arthropathy 3. Absence of rheumatoid factor 4. Enthesis changes 5. HLA-B27 association (50-90%)
47
What are 5 pathogens causing reactive arthritis?
Chlamydia trachomatis, Salmonella, Shigella, Yersinia, Campylobacter
48
What are the Jones Criteria major criteria?
Polyarthritis, Carditis, Chorea, Erythema marginatum, Subcutaneous nodules (need 2+ major OR 1 major + 2 minor)
49
What are the Jones Criteria minor criteria?
Arthralgia, Fever, Elevated ESR/CRP, Prolonged PR interval on ECG
50
What is required for Jones Criteria diagnosis?
Laboratory evidence of prior group A strep infection PLUS major/minor criteria
51
What are the Gustilo-Anderson classifications for open fractures?
Grade I: <1cm wound, minimal contamination. Grade II: 1-10cm wound, moderate contamination. Grade III: >10cm wound, high energy, severe contamination
52
What nerve injury is associated with distal radius fractures?
Median nerve (motor: OK sign, sensation: digits 1-3)
53
What nerve injury is associated with shoulder dislocation?
Axillary nerve (motor: deltoid, sensation: sergeant's patch)
54
What nerve injury is associated with knee dislocation?
Tibial or peroneal nerve (peroneal: weak dorsiflexion/eversion, sensation dorsum of foot)
55
What are 5 bones predisposed to avascular necrosis?
Femoral head, Talus, Scaphoid, Lunate, Capitate
56
What is the most common site of compartment syndrome?
Anterior compartment of the lower leg (tibia)
57
What are the "5 P's" and their significance?
Pain, Pallor, Paresthesias, Pulselessness, Paralysis - these are signs of acute arterial disruption, NOT compartment syndrome
58
What is the hallmark sign of compartment syndrome?
Pain out of proportion to injury/physical findings in conscious, alert patient
59
What is the key physical finding for compartment syndrome?
Pain on passive stretching of muscle groups in the affected compartment
60
What compartment pressure indicates need for fasciotomy?
Tissue pressure within 20 mmHg of diastolic BP or within 30 mmHg of MAP
61
What are the Salter-Harris classifications?
I: Through growth plate, II: Through metaphysis and growth plate (75%), III: Through epiphysis and growth plate, IV: Through all layers, V: Crush injury of growth plate
62
Which Salter-Harris fractures have highest risk of growth disturbance?
Types III
63
What are 10 complications of fractures?
Hemorrhage, Vascular injury, Nerve injury, Compartment syndrome, Osteomyelitis, AVN, CRPS, Fat embolism, Fracture blisters, Immobilization complications
64
What is fat embolism syndrome?
Fat globules in lung/circulation after long bone fracture. Signs: respiratory distress, confusion, thrombocytopenia, petechial rash, fever
65
When does fat embolism syndrome typically occur?
1-2 days post acute injury or IM nailing, up to 2% in long bone fractures
66
What is Complex Regional Pain Syndrome (CRPS) Type 1?
Pain syndrome after noxious event, disproportionate to inciting event, affects distal extremity, no evident peripheral nerve injury
67
What are CRPS diagnostic signs?
Allodynia/hyperalgesia, edema/sweating, not confined to single nerve distribution, motor/sensory dysfunction with distal-proximal gradient
68
What antibiotic prophylaxis for open fractures?
Grade I: Cefazolin. Grade II-III: Cefazolin + Gentamicin (or broad spectrum like Pip-Tazo)
69
What is the management priority for open fractures?
1. Recognize emergency 2. Begin irrigation 3. Antibiotics 4. Early debridement/irrigation in OR within 24 hours
70
What are greenstick vs torus fractures?
Greenstick: Incomplete angulated fractures of long bones. Torus: Incomplete fracture with wrinkling/buckling of cortex (can be very subtle)
71
What defines tenderness over epiphysis in children?
Salter I fracture
72
What is the difference between valgus and varus?
Valgus: angling AWAY from midline. Varus: angling TOWARD midline
73
What imaging is best for different orthopedic conditions?
CT: spine, knee, acetabulum, wrist, ankle. MRI: cartilage, ligaments, meniscus. US: cortical disruptions, long bones
74
What are 6 complications of prolonged immobility?
Pneumonia, DVT/PE, UTI, atrophy, stress ulcers, GI bleeding
75
What is the difference between delayed union
malunion
76
How long does fracture healing typically take?
2-4 months for bone consolidation in normal adults, callus appears at 3 weeks
77
Are open or closed fractures at higher risk for compartment syndrome?
Open fractures (but 30% of compartment syndrome patients had only soft tissue injuries without fracture)
78
What is the difference between sprain and strain?
Sprain: ligamentous injury from abnormal joint motion. Strain: musculotendinous injury from violent contraction/excessive stretch
79
What are the degrees of sprains/strains?
1st degree: minor tearing, mild swelling. 2nd degree: partial tear, moderate swelling. 3rd degree: complete tear
80
What is the difference between tendonitis and tendonosis?
Tendonitis: inflammatory condition with pain at tendinous insertions. Tendonosis: chronic degenerative changes
81
What fractures require urgent orthopedic consultation?
Long bone fractures, Open fractures, Fractures violating joints, Neurovascular compromise
82
What is the rule for describing fracture displacement?
Always describe the position of the DISTAL fragment relative to the proximal fragment
83
What are pathologic fractures?
Fractures through abnormal bone: cancer, cysts, osteogenesis imperfecta, scurvy, rickets, Paget's disease
84
What are stress fractures?
Repeated low-intensity forces leading to bone resorption. Common sites: tibia, fibula, metatarsals, femoral neck
85
What factors affect fracture healing?
Age, bone type (cancellous > cortical), fracture opposition, systemic states, drugs (steroids), exercise level
86
What are 10 historical red flags for back pain?
Trauma, prolonged steroid use, age >70, syncope, children, acute onset with flank/testicular/abdominal pain, diaphoresis, neurologic deficits, cancer history/weight loss/night pain, immunocompromised/IVDU/fever
87
What are 6 emergent diagnoses for back pain?
1. Aortic dissection 2. Cauda equina syndrome 3. Epidural abscess/hematoma 4. Meningitis 5. Ruptured/expanding AAA 6. Spinal fracture with cord/root impingement
88
What physical exam red flags suggest emergent back pain?
Hypotension/hypertension, tachycardia, fever, unequal BP in extremities, aortic insufficiency murmur, pulsatile abdominal mass, focal bony tenderness
89
What neurologic red flags require immediate evaluation?
Urinary retention, loss of rectal sphincter tone, focal lower extremity weakness
90
What are the L5 radiculopathy findings?
Decreased sensation first webspace of foot, weak great toe extension, normal reflexes
91
What are the S1 radiculopathy findings?
Decreased sensation lateral foot/small toe, weak plantar flexion, diminished/absent ankle jerk reflex
92
What percentage of disc herniations occur at L4-S1?
95% of herniations occur at L4-S1 spaces
93
What is the natural history of disc herniation?
2/3 resolve in 6 months on MRI, 75% of symptoms improve in 6 weeks
94
When is imaging indicated for back pain?
NOT indicated unless cauda equina suspected, other red flags present, or prolonged course
95
What defines compression above vs below L1?
Above L1: UMN findings (spinal cord). Below L1: LMN findings (cauda equina)
96
What is cauda equina syndrome?
Compression of nerve roots below L1 causing bladder/bowel dysfunction, saddle anesthesia, loss of anal wink
97
What is the first-line treatment for acute musculoskeletal back pain?
Moderate pain: Acetaminophen + NSAIDs. Severe pain: IV narcotics transitioning to PO
98
Are NSAIDs superior to acetaminophen for back pain?
No, NSAIDs are NOT superior to acetaminophen and risks must be considered
99
What is the evidence for muscle relaxants in back pain?
NO credible evidence supporting muscle relaxants or antispasmodic agents
100
What non-pharmacologic treatments help back pain?
Heat, spinal therapy, acupuncture, TENS units
101
What defines spinal stenosis vs disc herniation natural history?
Disc herniation improves over time; spinal stenosis worsens over time
102
What are the stages of disc herniation?
Protrusion → Extrusion → Sequestration (extrusion is usually symptomatic)
103
What cancers commonly metastasize to spine?
Breast, lung, prostate, kidney, thyroid
104
What infections can cause back pain?
Epidural abscess, osteomyelitis, discitis, paraspinal abscess
105
What vascular emergencies present as back pain?
Aortic dissection, ruptured/expanding AAA
106
What approach should be taken for unstable back pain patients?
Cardiac monitor, IV access, oxygen, aggressive fluid resuscitation if indicated, antibiotics if septic, emergent imaging
107
What medications can be used for chronic back pain through family doctor?
Gabapentin, TCAs (tricyclic antidepressants), injections
108
What requires a multidisciplinary approach?
Acute-on-chronic spells of back pain
109
What are concerning historical features for cancer?
Cancer history, weight loss, constitutional symptoms, pain worse at night or rest
110
What age groups are at higher risk for serious pathology?
Children (without clear mechanism) and patients >70 years old
111
What are risk factors for spinal infection?
Immunocompromised state, IVDU, recent bacterial infection, fever >38°C
112
What defines failure to improve with conservative therapy?
No improvement after 6 weeks of conservative treatment
113
What is the difference between acute ligamentous injury and muscle strain?
Ligamentous: abnormal joint motion. Muscle strain: violent contraction or excessive stretch
114
What common conditions are in the "stable" back pain category?
Acute ligamentous injury, acute muscle strain, degenerative joint disease, osteoarthritis
115
What referred causes should be considered for back pain?
Cholecystitis, pancreatitis, nephrolithiasis, ovarian pathology, endometriosis, prostatitis
116
What is the significance of morning stiffness in back pain?
Suggests inflammatory conditions like ankylosing spondylitis
117
What activities typically worsen mechanical back pain?
Forward flexion, lifting, prolonged sitting
118
What activities typically improve inflammatory back pain?
Movement and activity (vs. mechanical pain which worsens with activity)
119
What is the appropriate follow-up for uncomplicated back pain?
Return if no improvement in 1-2 weeks, or immediately for red flag symptoms
120
What is the most important counseling point for patients with acute back pain?
Expected timeline for improvement (75% improve in 6 weeks) and when to return for evaluation
