Osteoarticular pathology is a very frequent motive for consultation. Very often, the diagnosis relies upon symptomatology, and the physi­ cian requires confirmatory radiological investigations. Whatever the clinical indication, the interpretation of radiological data must be very rigorous. On the basis of a complete description of the radiographic images, according to a systematic analysis plan, a certain number of diagnostic hypotheses may be proposed. Selection of the most likely hypothesis requires the correlation of clinical, biological, and radiological data, and may sometimes necessi­ tate additional investigations, such as tomograms, scintigrams, and computed tomography (CT). 1 Part One Iconography 3 3 1 2 4 5 5 6 6 7 8 b a 8 a 9 10 11 12 10 13 14 11 15 a b 12 a c 13 17 b a c 14 15 c 16 17 23 21 a 22 b 18 19 20 21 22 23 33 34 24 25 37 38 26 27 40- 43 28 29 46 30 48 47 31 49 50 32 33 52 a b c 34 53 a b d c 35 54 a b 36 37 55 a 38 55 b c 39 56 57 40 58 41 60 61 42 43 63 64 44 65 66 45 67 68 46 69 a b 47 70 71 48 73 49 74 75 50 76 77 51 78 79 52 80 a b c 53 81 82 54 83 84 55 85 86 S6 87 88 57 89 90 58 91 92