MSK / Rheumatology Dashboard

Most common organism: S. aureus (all ages). Sickle cell → also Salmonella . Vertebral → S. aureus, often IV drug users .
Spread: children → hematogenous to metaphysis of long bones; adults → often contiguous (diabetic foot — positive probe-to-bone ) or vertebral.
Imaging: X-ray changes lag 10–14 days ; MRI is best early test. Chronic → sequestrum (dead bone) + involucrum.
Routes: non-hematogenous ~80% of adult cases — direct inoculation/contiguous (surgery, trauma, hardware, diabetic foot, pressure ulcers), often polymicrobial ; hematogenous ~20% — bloodborne, mostly children , usually monomicrobial . Pseudomonas with puncture wounds through the sole.
Labs: ↑ESR/CRP (CRP trends treatment response — persistent elevation suggests failure); WBC may be normal, especially in chronic disease. Blood cultures positive in ~50%. Chronic hallmark = draining sinus tract (pathognomonic) + sequestrum.
Diagnosis: bone biopsy/culture is gold standard (superficial wound cultures correlate poorly). Treatment: organism-directed IV antibiotics — 4–6 weeks acute, &gt;8 weeks for chronic/MRSA — empiric vancomycin for MRSA ± debridement; remove infected hardware.

Welcome to your MSK / Rheumatology study hub 🦴

Each numbered section has full study content, followed by a 50-question quiz. A 60-question midterm and a cumulative 300-question final pull it all together.

How to use: read a section, then take its quiz — answers lock and show a rationale. Quizzes score themselves. ⭐ orange boxes = high-yield; 🔵 blue boxes = clinical pearls.

The one rule of MSK/Rheum: separate mechanical/structural problems (focal, activity-related, normal inflammatory labs) from inflammatory/systemic disease (morning stiffness >60 min, multiple joints, elevated ESR/CRP, systemic features). That split drives your workup, imaging, and referral.