Musculoskeletal & Connective-Tissue Disorders – Master Flashcards

Flashcards cover key diagnostic criteria, antibodies, treatments, physical signs, imaging findings, red-flags, and disease associations across connective-tissue and musculoskeletal disorders.

What autoantibody is highly sensitive but not specific for Systemic Lupus Erythematosus (SLE)?

Antinuclear antibody (ANA)

Name two autoantibodies that are highly specific for SLE.

Anti-dsDNA and anti-Smith (anti-Sm) antibodies

Which form of lupus is limited to the skin and often causes scarring lesions?

Discoid Lupus Erythematosus (DLE)

Which lupus subtype presents with annular, non-scarring lesions that worsen with sun exposure?

Subacute Cutaneous Lupus Erythematosus (SCLE)

What antibody is characteristic of Drug-Induced Lupus?

Anti-histone antibody

What is the most serious complication of Neonatal Lupus?

Congenital heart block

First-line long-term, flare-preventive drug for SLE skin & joint disease?

Hydroxychloroquine

SLE treatment used for refractory disease that targets B-cell survival factor BLyS?

Belimumab

List any 4 clinical items from the 2012 SLICC SLE criteria.

Malar rash, discoid rash, photosensitivity, oral ulcers, arthritis, serositis, renal disorder, neurologic disorder, hematologic disorder, immunologic disorder, positive ANA (any 4)

What complement levels are typically low during an SLE flare?

C3 and C4

Which autoantibody is classically positive in Sjögren syndrome?

Anti-Ro (SSA) (often accompanied by Anti-La (SSB))

Dry eyes + dry mouth + lymphocytic sialadenitis on lip biopsy: diagnosis?

Sjögren syndrome

What antibody is associated with Diffuse cutaneous Systemic Sclerosis and predicts ILD?

Anti-Scl-70 (anti-topoisomerase I)

Raynaud + sclerodactyly + telangiectasias + anti-centromere Ab: likely subtype?

Limited cutaneous Systemic Sclerosis (CREST)

Which systemic sclerosis autoantibody predicts scleroderma renal crisis?

Anti-RNA polymerase III

Key lung screening study for systemic sclerosis patients?

High-resolution CT (HRCT) of the chest plus PFTs

Triad of Mixed Connective Tissue Disease (MCTD) clinical overlap + antibody?

Features of SLE, scleroderma, polymyositis; high-titer anti-U1-RNP

Most common extra-articular lung complication in Rheumatoid Arthritis?

Interstitial lung disease / pulmonary fibrosis

Classic triad of Felty’s syndrome in RA.

Rheumatoid arthritis, splenomegaly, neutropenia

Antibody strongly associated with Antiphospholipid Syndrome lab diagnosis?

Lupus anticoagulant OR anticardiolipin OR anti-β2-glycoprotein I (any)

What INR range is targeted for long-term warfarin therapy in APS?

INR 2.0 – 3.0

HLA allele strongly linked to Ankylosing Spondylitis.

HLA-B27

HLA allele associated with celiac disease (name either).

HLA-DQ2 or HLA-DQ8

Name the genetic defect in Marfan syndrome.

Mutation in FBN1 gene encoding fibrillin-1

Classic cardiac lesion requiring surveillance in Marfan patients.

Aortic root dilation / risk of dissection

Most common life-threatening complication of Ehlers-Danlos vascular type (vEDS).

Arterial or organ rupture (esp. large arteries)

Polymyalgia Rheumatica initial drug and dose range?

Low-dose prednisone 10–20 mg daily

Elevated CK + proximal muscle weakness + anti-Jo-1 antibody: diagnosis?

Polymyositis (anti-synthetase syndrome if ILD also present)

Inclusion Body Myositis weakness pattern hallmark?

Asymmetric weakness affecting finger flexors & quadriceps; poor steroid response

CRP vs ESR: which rises and falls faster with acute inflammation?

CRP rises and falls faster

Synovial fluid WBC > 50,000/µL with >90 % neutrophils suggests?

Septic arthritis

Birefringence & crystal shape in gout under polarized light?

Needle-shaped, negatively birefringent monosodium urate crystals

Calcium pyrophosphate crystals birefringence & shape?

Rhomboid, weakly positively birefringent (pseudogout)

Interpretation of fat globules in joint aspirate after trauma.

Lipohemarthrosis → intra-articular fracture

First imaging for suspected osteoarthritis.

AP & lateral plain X-rays showing joint-space narrowing, osteophytes

Key differentiating feature of RA vs OA on imaging.

RA shows symmetric erosions & periarticular osteopenia; OA shows osteophytes & joint-space narrowing without erosions

Drug of choice for acute gout attack when no renal/GI contraindication.

NSAIDs (e.g., indomethacin)

Target serum uric acid level for chronic gout prophylaxis.

< 6 mg/dL

Mainstay treatment for polymyositis & dermatomyositis.

High-dose corticosteroids with steroid-sparing immunosuppressants (e.g., methotrexate)

Best initial therapy for Raynaud phenomenon in systemic sclerosis.

Dihydropyridine calcium-channel blocker (e.g., nifedipine)

Cauda equina syndrome key red-flag symptoms (list 2).

Saddle anesthesia, new urinary retention or fecal incontinence, bilateral leg weakness

Straight-leg-raise reproduces pain down below knee — diagnosis?

Lumbar radiculopathy (usually L4/L5 or L5/S1 disc herniation)

Classic 'sunburst' periosteal pattern on X-ray suggests which bone tumor?

Osteosarcoma

Most common benign bone tumor presenting as cartilage-capped bony outgrowth.

Osteochondroma

Ewing sarcoma translocation chromosome abnormality?

t(11;22)(q24;q12) → EWSR1-FLI1 fusion

Preferred imaging modality for early osteomyelitis.

MRI of affected bone

Empiric IV antibiotics for septic arthritis of native joint in adults.

Vancomycin plus third-generation cephalosporin until cultures return

Most common causative organism of osteomyelitis in sickle-cell disease.

Salmonella species

What pediatric apophyseal overuse injury causes heel pain in active children?

Sever disease (calcaneal apophysitis)

Knee pain at tibial tubercle in adolescent athletes = ____ disease.

Osgood-Schlatter disease

Name two Ottawa ankle rule criteria that mandate ankle X-ray.

Bone tenderness at posterior edge/tip of either malleolus OR inability to bear weight immediately and in ED (4 steps)

Compartment syndrome hallmark clinical finding.

Severe pain out of proportion, especially with passive stretch

First step in suspected necrotizing fasciitis management.

Emergent broad-spectrum IV antibiotics and surgical consultation for debridement

Classic radiographic feature of rickets at metaphysis.

Cupping and fraying of metaphyseal ends

Bisphosphonate MOA used in osteoporosis.

Inhibit osteoclast-mediated bone resorption

Humeral mid-shaft fracture risks injury to which nerve producing wrist drop?

Radial nerve

Scapular winging after radical mastectomy indicates damage to which nerve?

Long thoracic nerve (serratus anterior)

Positive Finkelstein test indicates which diagnosis?

De Quervain’s tenosynovitis

Drop-arm test inability to slowly lower arm indicates tear of which tendon?

Supraspinatus

Positive empty-can (Jobe) test localizes weakness to which rotator cuff muscle?

Supraspinatus muscle

Bouchard nodes occur at which finger joints?

Proximal interphalangeal (PIP) joints

Heberden nodes occur at which finger joints?

Distal interphalangeal (DIP) joints

Trendelenburg gait indicates weakness of which muscle and nerve?

Gluteus medius/minimus weakness (superior gluteal nerve)

Gait pattern with high stepping due to foot drop is called?

Neuropathic (steppage) gait

Most common site of osteoid osteoma.

Cortex of proximal femur or tibia

Typical symptom relief characteristic of osteoid osteoma.

Night pain relieved by NSAIDs/aspirin

What test is used in newborns to dislocate an unstable hip (DDH)?

Barlow maneuver

What maneuver reduces a dislocated neonate hip?

Ortolani maneuver

Greenstick fracture definition.

Incomplete fracture where one cortex breaks and the other bends

Medial epicondyle apophysitis in young baseball pitchers is called ____ elbow.

Little League elbow

Radiographic ‘onion-skin’ periosteal reaction in diaphysis of long bone indicates?

Ewing sarcoma

Initial management of osteoarthritis pain when acetaminophen ineffective.

NSAIDs (topical or oral)

Define pseudogout crystal appearance under light microscopy.

Rhomboid, positively birefringent calcium pyrophosphate

Drug that lowers uric acid by inhibiting xanthine oxidase.

Allopurinol or febuxostat

Mainstay prophylaxis during first 6 months of urate-lowering therapy.

Low-dose colchicine or NSAID

Positive Phalen maneuver reproduces numbness in which fingers?

Thumb, index, middle, and radial half of ring finger (median nerve)

Typical empiric antibiotics for human bite wound to hand.

Amoxicillin-clavulanate

Treatment of choice for compartment syndrome.

Urgent fasciotomy

What constitutes a positive Adson test?

Loss of radial pulse with head turned toward tested side and deep inspiration → thoracic outlet syndrome

Anal wink reflex root level.

S2–S4

Primary lab marker to track muscle injury severity in rhabdomyolysis.

Serum creatine kinase (CK)

Neer impingement sign targets which tendon under acromion?

Supraspinatus tendon (subacromial impingement)

Mainstay therapy for vertebral osteomyelitis due to MRSA.

6–8 weeks IV vancomycin plus possible surgical debridement

Name any two red-flag features in low-back pain that warrant immediate imaging.

Age

Bone scan isotope commonly used to detect skeletal metastasis.

Technetium-99m-labeled diphosphonate

What does a T-score ≤ −2.5 on DEXA indicate?

Osteoporosis

Earliest imaging change in Paget disease of bone.

Focal lytic lesion with cortical thickening on X-ray

Child with heel pain after growth spurt, tenderness at posterior calcaneus; diagnosis?

Sever disease (calcaneal apophysitis)

Foot drop nerve and root level.

Common peroneal (fibular) nerve, root L4–L5

What pharmacologic class prevents bone resorption in osteoporosis by inducing osteoclast apoptosis?

Bisphosphonates

Describe Murphy (McMurray) test purpose.

Assesses meniscal tear; pain/click with rotation during knee extension

Tension of pelvic floor muscles causing chronic pelvic pain is termed?

Pelvic floor tension myalgia

Best initial step in suspected acute septic arthritis of native knee.

Urgent arthrocentesis for Gram stain, culture, and cell count

Osteogenesis Imperfecta Type I hallmark clinical triad.

Multiple childhood fractures, blue sclerae, hearing loss later in life