07/07/2026
50 diagnoses cover the majority of high-yield musculoskeletal conditions repeatedly tested across USMLE
1. Osgood-Schlatter disease – Adolescent athlete, tibial tubercle pain, worse with jumping.
2. Legg–Calvé–Perthes disease – Boy 4–8 years, avascular necrosis of femoral head, painless limp.
3. Slipped capital femoral epiphysis – Obese adolescent, hip pain referred to knee, externally rotated leg.
4. Developmental dysplasia of the hip – Positive Ortolani/Barlow, asymmetric skin folds.
5. Septic arthritis – Hot swollen joint, inability to bear weight, S. aureus.
6. Osteomyelitis – Bone pain + fever, S. aureus most common.
7. Ewing sarcoma – Onion-skin periosteum, t(11;22).
8. Osteosarcoma – Sunburst appearance, Codman triangle, around knee.
9. Osteochondroma – Most common benign bone tumor, cartilage-capped exostosis.
10. Giant cell tumor of bone – Soap-bubble appearance, epiphysis, multinucleated giant cells.
11. Plantar fasciitis – Heel pain with first steps in the morning.
12. Achilles tendinopathy – Posterior heel pain, overuse.
13. Achilles tendon rupture – Sudden pop, positive Thompson test.
14. Patellofemoral pain syndrome – Anterior knee pain, stairs, movie theater sign.
15. Patellar tendon rupture – Cannot extend knee after jump.
16. Anterior cruciate ligament injury – Non-contact pivot injury, Lachman test.
17. Posterior cruciate ligament injury – Dashboard injury, posterior drawer.
18. Medial collateral ligament injury – Valgus stress injury.
19. Lateral collateral ligament injury – Varus stress injury.
20. Meniscal tear – Locking/catching, McMurray test.
21. Rotator cuff tear – Unable to abduct, positive drop-arm test.
22. Shoulder impingement syndrome – Positive Neer/Hawkins tests.
23. Adhesive capsulitis – Diabetes, loss of active and passive ROM.
24. Shoulder dislocation – Most common, axillary nerve injury.
25. Lateral epicondylitis – Tennis elbow, wrist extension pain.
26. Medial epicondylitis – Golfer’s elbow.
27. Carpal tunnel syndrome – Median nerve, thenar atrophy, positive Phalen/Tinel.
28. De Quervain tenosynovitis – Thumb pain, positive Finkelstein test.
29. Trigger finger – Finger locking due to A1 pulley.
30. Dupuytren contracture – Palmar fibrosis, 4th/5th fingers.
31. Compartment syndrome – Pain out of proportion, pain with passive stretch.
32. Fat embolism syndrome – Long bone fracture + petechiae + hypoxemia.
33. Complex regional pain syndrome – Severe pain after injury, autonomic changes.
34. Paget disease of bone – ↑ALP, hearing loss, enlarged skull.
35. Osteoporosis – Fragility fractures, normal calcium.
36. Osteomalacia – Vitamin D deficiency, Looser zones.
37. Rickets – Bowed legs, rachitic rosary.
38. Avascular necrosis – Steroids, alcohol, sickle cell disease.
39. Fibromyalgia – Widespread pain, fatigue, normal inflammatory markers.
40. Polymyalgia rheumatica – Older adult, shoulder/hip stiffness, ↑ESR, responds to steroids.
41. Rheumatoid arthritis – MCP/PIP symmetric arthritis, morning stiffness >1 hour.
42. Osteoarthritis – DIP joints, Heberden nodes, worse with use.
43. Gout – First MTP, needle-shaped negatively birefringent crystals.
44. Calcium pyrophosphate deposition disease – Chondrocalcinosis, positively birefringent rhomboid crystals.
45. Ankylosing spondylitis – HLA-B27, bamboo spine, uveitis.
46. Psoriatic arthritis – Dactylitis, nail pitting, pencil-in-cup deformity.
47. Reactive arthritis – Can’t see, can’t p*e, can’t climb a tree.
48. Systemic lupus erythematosus – Non-erosive arthritis with multisystem disease.
49. Dermatomyositis – Heliotrope rash, Gottron papules, proximal muscle weakness.
50. Polymyositis – Symmetric proximal muscle weakness, elevated CK.
