Bubbly or lytic lesions (FEGNOMASHIC): fibrous dysplasia (no periosteal reaction, mention adamantinoma if in tibia or jaw; pelvis, proximal femur, ribs, skull, long lesion in long bone, expansile medullary lytic lesion, ground glass, well-defined sclerotic margin, bowing deformities, base of skull sclerotic, hot on bone scan, cherubism in mandible and maxilla, craniofacial in facial and frontal bones, pseudoarthrosis of tibia, Mccune Albright is polyostotic FD with café-au-lait spots with precocious puberty), enchondroma (must have calcifications except in phalanges, no periostitis; tubular bones, chondroid calcifications, endosteal scalloping, pain is malignant, Ollier’s enchondromatosis, Mafucci’s enchondromatosis with multiple ST hemangiomas), EG (age<30; lytic lesion can look aggressive, skull lesion beveled-edge appearance, sequestrum, floating tooth, vertebra plana, lung dz, pituitary, RES), GCT (epiphyses must be closed, must be epiphyseal and abut the articular surface in long bones, eccentric, well-defined but nonsclerotic border except in flat bones; long tubular bone > spine or sacrum, 50% at knee), NOF (age<30, no periostitis, cortically based; metaphysis), osteoblastoma (mention with ABC even if age>30, especially in posterior elements of spine), mets (age>40; renal and thyroid), myeloma (age>40; plasmacytoma in ilium and sacrum, cold on bone scan; vertebral bodies destroyed before pedicles, axial skeleton, long bones, punched-out lytic lesions, generalized osteopenia, skeletal survey more sensitive), ABC (age<30, expansile, eccentric, pain, fluid-fluid levels on MR; posterior elements of spine, metaphysis of long bones, pelvis), SBC (age<30, central, no periostitis; proximal humerus, proximal femur, calcaneus, fallen fragment sign), HPT (brown tumor, must have other evidence of HPT), infection (always mention), chondroblastoma (age<30, epiphyseal), chondromyxoid fibroma (mention with NOF, no calcified matrix)
Automatics (must mention in every case): age<30 – infection, EG; age>40 – infection, mets, myeloma
Multiple lytic lesions (FEEMHI): fibrous dysplasia, enchondromas, EG, mets, myeloma, HPT, infection
Rib lesions (FAME): fibrous dysplasia, ABC, mets, myeloma, enchondroma, EG
Lytic epiphyseal lesion (also apophyseal, carpal and tarsal bones, patella): chondroblastoma, infection, EG, GCT, geode; age>40 – add mets and myeloma and remove chondroblastoma
Lytic lesion in posterior elements of spine (OAT): osteoblastoma, ABC, TB
Exclude these lytic lesions if age>30 (CANES): chondroblastoma, ABC, NOF, EG, SBC
Lesions that have no pain or periostitis (FENS): fibrous dysplasia, enchondroma, NOF, SBC
Bony sequestrum (FILE): fibrosarcoma, infection, lymphoma, EG, osteoid osteoma (mimic)
Geodes (CARD): CPPD, AVN, RA, DJD, trauma
Sclerotic lesion age 20-40: chondroblastoma, ABC, NOF, EG, SBC, fibrous dysplasia, infection, HPT (healing brown tumor), osteoid osteoma, giant bone island; age>40 - mets
Endosteal scalloping: fibrous dysplasia, enchondroma, cartilaginous tumor
Wide zone of transition (permeative): mets + myeloma, reticulum cell sarcoma, Ewing’s sarcoma, infection, EG
Malignant bone tumors: age<30 – Ewing’s sarcoma (diaphysis long bones > flat bones, aggressive, ST mass typical, medullary location), osteosarcoma (poorly defined intramedullary metaphyseal mass lesion extends through cortex, osteoid or chondroid matrix, aggressive periosteal reaction with Codman triangle or sunburst pattern, telangiectatic form purely lytic and simulates ABC, parosteal form is low-grade and seen in posterior distal femur with more mature ossification centrally), mets in children (neuroblastoma, leukemia/lymphoma, Wilm’s); age>40 – mets + myeloma, chondrosarcoma (pain, long bones, pelvis, ribs, clivus, most metaphyseal); age 30-40 – GCT (if lung mets or recurrence), parosteal osteosarcoma (densest calcification is central), fibrosarcoma (almost always lytic), malignant fibrous histiocytoma (mention with fibrosarcoma, aggressive, large soft tissue mass), reticulum cell sarcoma (primary lymphoma of bone, looks like Ewing’s sarcoma, often asx)
Permeative lesion in child: Ewing’s sarcoma, infection, EG
Permeative lesion in older pt: infection, mets, myeloma, malignant fibrous histiocytoma, reticulum cell sarcoma
Soft tissue tumors: MFH, liposarcoma (may or may not have fat), synovial sarcoma (usu extraarticular), synovial osteochondromatosis (multiple Ca++ loose bodies, jt effusion, erosions, destruction; knee, hip, elbow; mimics PVNS if not Ca++), pigmented villonodular synovitis (hemosiderin deposits lining synovium, erosions, jt destruction, no joint space narrowing), hemangiomas (phleboliths, cortical holes, striated vertebral body)
Malignant transformation of bony lesions: fibrous dysplasia – fibrosarcoma, OSA, MFH; Paget’s – OSA; osteomyelitis with draining sinus – SCC; radiation – OSA, chondrosarcoma, MFH; bone infarct – fibrosarcoma, MFH; Ollier’s – chondrosarcoma; Maffucci’s – chondrosarcoma; osteochondroma - chondrosarcoma
Cortical holes (pseudopermeative lesion): osteoporosis (metacarpal cortex less then ¼ to 1/3 of metacarpal), radiation, hemangiomas
Focal cortical thickening: stress fracture, infection, osteoid osteoma
Mets to bone: PBKTL; P – mostly blastic, B – mixed, K – purely lytic, TL – mostly lytic
Hallmarks of DJD: joint space narrowing (asymmetric), subchondral sclerosis, osteophytes, subchondral cysts, lack of osteoporosis or erosions
Joints that exhibit erosions with OA: TMJ, SI, AC, pubic symphysis
Hallmarks of RA: soft tissue swelling, periarticular and diffuse osteoporosis, joint space narrowing, marginal erosions (including ulnar styloid and triquetrum, proximal distribution (hands), bilaterally symmetric, subchondral cysts, ulnar deviation, carpal instability, rotator cuff tear, distal clavicle resorption, axial migration, protrusio acetabuli, A-a subluxation, may see rice bodies in synovial inflammation; secondary DJD – severe JSN out of proportion to sclerosis and osteophytes
Hallmarks of HLA-B27 spondyloarthropathies: bony ankylosis, proliferative new bone formation, predominantly axial (spinal) involvement, syndesmophytes
Sacroiliac joint involvement: AS (bamboo spine, Andersen lesion and pseudoarthrosis), IBD (like AS), psoriasis (distal predominance, sausage digit, pencil-in-cup, acroosteolysis, proliferative erosions, STS, periostitis, bony ankylosis, arthritis mutilans deformities, heel spur with fuzzy margins), Reiter’s syndrome (like psoriasis but feet>hands, IP joint great toe), DJD, infection, gout, HPT; bilateral + symmetric SI jt + marginal symmetric syndesmophytes – usually AS or IBD; unilateral or asymmetric SI jt – exclude AS and IBD and consider psoriasis and Reiter’s
Large joint involvement: DJD (superolateral migration in hips, medial compartment of knee most affected), RA (axial migration in hips), CPPD, AS (resembles RA), PVNS, synovial osteochondromatosis, infection (Staph aureus most common, Salmonella in SCD, joint effusion, joint destruction, crosses disc space in spine, periosteal reaction, bone destruction, Brodie’s abscess is well-defined lytic lesion with thick sclerotic border, sequestrum), amyloidosis (nodular synovitis with erosions resembling RA), ochronosis (DSN with vacuum, disc calcifications, generalized osteoporosis, secondary OA)
Arthropathy distribution in hands and wrists: distal – psoriasis, Reiter’s syndrome, osteoarthritis; proximal – RA, CPPD
Bilateral symmetry of arthropathy: primary OA (middle-aged women in hands only, 1st CMC, gull-wing erosive pattern), RA, multicentric reticulohistiocytosis (multiple erosions predominantly in phalanges without osteoporosis)
Monoarticular arthritis: CHRIST – crystal arthropathies, hemophilia, RA, infection, synovial (synovial osteochondromatosis, PVNS), trauma
Normal mineralization: DJD, CPPD, gout, multicentric reticulohistiocytosis, PVNS, synovial osteochondromatosis
Hallmarks of gout: well-defined erosions often with sclerotic borders or overhanging edges, soft tissue nodules that calcify in presence of renal failure, random distribution in hands without marked osteoporosis, podagra (1st MTP jt), often have chondrocalcinosis, preserved joint space, olecranon/prepatellar bursitis
Hallmarks of CPPD: pain, cartilage calcification (knee, triangular fibrocartilage of wrist, pubic symphysis), joint destruction from secondary DJD (shoulder, elbow, radiocarpal jt, patellofemoral jt), subchondral cysts, can present as pseudogout
CPPD-associated disorders: primary HPT, gout, hemochromatosis (DJD 2nd-4th MCP jts with squaring of metacarpal heads with drooping osteophytes, generalized osteoporosis)
Hallmarks of collagen vascular diseases: osteoporosis and soft tissue wasting in the hands, erosions generally not present; SLE - ulnar deviation of phalanges, nonerosive, resembles Jaccoud’s arthropathy; scleroderma - ST calcifications, acroosteolysis, severe resorption of 1st CMC with radial subluxation of 1st metacarpal; dermatomyositis - widespread ST calcifications, radial subluxation of IP joint of thumb
Charcot joint: joint destruction, dislocation, heterotopic new bone; causes – DM, spinal cord injury, alcohol abuse, myelomeningocele/syringomyelia
Epiphyseal enlargement and gracile diaphyses: hemophilia (hemarthrosis, secondary OA, widened intercondylar notch, enlarged trochlear notch, subchondral cysts; pseudotumor – large ST mass with adjacent bone destruction, hematoma, Ca++ common), JRA (diffuse ankylosis of posterior articular joints, periosteal new bone formation, STS, short metacarpals), paralysis
Hallmarks of AVN: increased bone density at otherwise nl jt; joint effusion, patchy or mottled density, subchondral lucency, articular surface collapse and joint fragmentation, low signal serpiginous border on MR; causes – trauma, steroids, sickle cell anemia, renal disease, collagen vascular diseases, alcoholism, idiopathic; OCD at lateral aspect of medial femoral condyle, talus, capitellum; SONK in elderly at weight bearing medial femoral condyle
Hallmarks of osteomalacia: osteopenia, Looser’s fxs (femur, pelvis, scapula), epiphyseal flaring and irregularity, bending of long bones
Hallmarks of HPT: subperiosteal resorption in radial aspect of middle phalanges, medial aspect of proximal tibia, SI jts, distal clavicle resorption, rugger jersey spine, brown tumors, sclerosis, salt and pepper skull, ST calcifications, chondrocalcinosis
Dense bones: renal osteodystrophy (2o HPT, osteomalacia), sickle cell disease (bone infarcts, dactylitis, H shaped or fish vertebrae, AVN hip, hair on end skull, osteomyelitis, spleen autoinfarction, cholelithiasis, papillary necrosis), myelofibrosis (splenomegaly and extramedullary hematopoeisis), osteopetrosis (“bone in bone, sandwich vertebrae”, erlenmeyer flask, dense base of skull), pyknodysostosis (distal phalanges pointed and dense, tufts absent, widened sutures, straight angle mandible), mastocytosis (thickened SB folds with nodules), mets (breast and prostate), Paget’s disease (bony enlargement, commonly in pelvis with thickened iliopectineal line, lytic phase with flame-shaped or blade of grass leading edge that always starts at end of bone except in tibia, cotton wool skull, 2o OSA, thickened trabeculae, protrusio acetabuli, picture frame vertebral body, ivory vertebral body, osteoporosis circumscripta, diploic widening, bowing of bones), athletes, fluorosis (ligamentous calcification, sacrotuberous ligament) – 3MsPROOF
Periostitis without underlying bony lesion: trauma, HPO (painful periostitis of long tubular bones; causes - lung cancer, benign fibrous tumor of pleura, mets, mesothelioma, chronic pulmonary infection), venous stasis (lower extremities), thyroid acropachy (occurs post thyroidectomy, metacarpals and phalanges, esp ulnar aspect of 5th metacarpal), pachydermoperiostosis (like HPO but rarely painful)
Periosteal reaction in children: scurvy (dense metaphyseal lines), Caffey’s (tibia, ulna, mandible), trauma, hypervitaminosis, leukemia, lymphoma, neuroblastoma, infection, physiologic, prostaglandins - SCALP
Don’t Touch” lesions: posttraumatic lesions – myositis ossificans (peripheral circumferential calcification with lucent center), avulsion injury (cortical irregularity and periostitis at ligament or tendon insertion site, lesser trochanter avulsion suggests mets), cortical desmoid (posteromedial epicondyle of femur), geodes, discogenic vertebral sclerosis (variant of Schmorl’s node), fracture (if not immobilized), pseudodislocation of humerus (inferior subluxation from fracture and hemarthrosis); normal variants – dorsal defect of patella (lytic defect upper outer quadrant), pseudocyst of humerus (lytic area at greater tuberosity), os odontoideum (smooth well-corticated inferior border of dens and hypertrophied densely corticated anterior arch of C1); benign lesions – NOF, bone islands (asymptomatic, usually oblong with long axis in axis of stress, trabeculae extend into nl bone spiculated), SBC (do not prophylactically curettage if in calcaneus), pseudocyst of calcaneus, bone infarct (dense serpiginous border), Pitt’s pit (lytic lesion at lateral aspect of femoral neck); osteoma (facial bones, skull, Gardner’s)
Miscellaneous bone lesions: achondroplasia (shortened long bones with narrowing of interpedicular distance in caudal direction, posterior vertebral body scalloping), melorrheostosis (thickened cortical new bone like “dripping candle wax”, follows sclerotome), mucopolysaccharidoses (flattened vertebral bodies with anterior beak, flared iliac wings and broad femoral necks, pointed proximal 5th metacarpal base with notch appearance to ulnar aspect, posterior vertebral body scalloping), multiple hereditary exostosis (osteochondromas, metaphyseal, lesion grows away from joint, undertubulation, knees, proximal femur, axial more prone to degeneration), osteoid osteoma (pain, age<30, lucent nidus surrounded by reactive sclerosis in cortex of long bone, can be on concave side of painful scoliosis, “double density” sign on bone scan), osteopathia striata (multiple 2-3mm thick linear bands of sclerotic bone aligned parallel to long axis of bone, asymptomatic), osteopoikilosis (hereditary, asymptomatic, multiple small sclerotic densities on ends of long bones and pelvis), sarcoid (“lace-like” pattern of bony destruction in hands), SCFE (overweight teenage boys, line through lateral femoral neck does not intersect with portion of epiphysis, can be complication of hypothyroidism), DISH (flowing anterior osteophytes at least 4 contiguous vertebral bodies without DSN or sclerosis), reflex sympathetic dystrophy (=Sudeck’s atrophy, severe patchy osteoporosis and STS following minor trauma), acromegaly (skull thickening, enlarged sinuses and sella turcica, hypertrophied terminal tufts with spade appearance, posterior vertebral body scalloping, elongated and widened vertebral bodies, heel pad thickening), transient osteoporosis of the hip (pain, self-limited, low T1 signal, hot on bone scan), tarsal coalition (talar beak, sclerosis of middle facet of subtalar joint), intraosseous lipoma (asx, proximal femur, fibula, calcaneus, may have central calcified nidus); OPLL (C-spine); Poland’s syndrome (absence of pectoral muscles and syndactyly); congenital rubella (“celery-stalk” metaphysis)
Dense base of skull: fibrous dysplasia, Engelmann’s disease (kids, cortical thickening midshaft of long bones involving both periosteal and endosteal surfaces), Von Buchem’s disease (adults), Paget’s disease, meningioma, pyknodysostosis, osteopetrosis
Lytic skull lesion: SCD, HPT, Paget’s, FD, TS, infection, mets, myeloma, EG, epidermoid, hemangioma
Wormian bones: pyknodysostosis, OI, cleidocranial dysplasia (absent distal clavicles, supernumerary teeth), hypothyroidism, pachydermoperiostosis, Down’s – PORKCHOPS
Atlanto-axial subluxation: RA, trauma, Down’s, Morquio’s, POOF
High-riding shoulder: RA, CPPD, torn rotator cuff
Distal clavicle resorption: RA, HPT, osteomyelitis, weightlifting, trauma, scleroderma
Inferior rib resorption: vascular impression (coarctation), HPT, NF
Madelung’s deformity: Hurler’s, infection, trauma, dyschondrosteosis, osteochondromatosis, chromosomal anomalies (Turner’s) – HITDOC
Radial hypoplasia: VACTERL, Holt-Oram syndrome, thrombocytopenia-absent radius syndrome
Ulnar variance: negative – Kienbock’s; positive – TFCC tear, ulnar impingement syndrome
Distal tuft resorption: scleroderma, psoriasis, Raynaud’s, vascular disease, frostbite, electrical burns, tabes dorsalis, HPT, pyknodysostosis – PINCH; band-like – polyvinyl chloride, Hajdu-Cheney syndrome
Lytic finger: enchondroma, glomus tumor (pain, terminal phalanx), epidermoid inclusion cyst, mets, infection, sarcoid, erosive arthropathy
Polydactyly: familial, chondroectodermal dysplasia, trisomy 13, Meckel-Gruber
Short 4th metacarpal: idiopathic, pseudohypoparathyroid (brachydactyly), pseudopseudohypoparathyroid, Turner’s, basal cell nevus syndrome (mandibular cysts, dural calcifications)
Sclerotic vertebral body: LIMMP – lymphoma, infection, mets, myeloma, Paget’s
Vertebral body lesion: Paget’s, osteoporosis, HPT, LIMP, myeloma, hemangioma, SCD, HLA-B27, EG, GCT, osteoblastoma, ABC, TB, osteoid osteoma
Platyspondyly: diffuse - dwarf, OI, Morquio’s, epiphyseal dysplasia, Cushing’s; solitary or multifocal – EG, infection, trauma, mets, myeloma, lymphoma, leukemia, SCD, osteonecrosis (with vacuum disc phenomenon)
Anterior vertebral body beaking: Morquio’s (middle), others (inferior) – Hurler, achondroplasia, Downs
Posterior vertebral scalloping: dural ectasia (NF, Marfan’s, Ehlers-Danlos), syrinx, spinal canal tumor, congenital (achondroplasia, mucopolysaccharidoses, OI), acromegaly
Posterior spinal fusion: Klippel-Feil, surgical fusion, JRA, HLA-B27
Fused vertebrae: isolated, trauma, Klippel-Feil
Lytic ilium: FD, ABC, SBC, hemophilia, mets, plasmacytoma, Ewing’s sarcoma, chondrosarcoma, lymphoma
Lytic sacrum: met, chordoma (sacrum, clivus, vertebral bodies, expansile lytic lesion with large ST component and variable calcifications), plasmacytoma, chondrosarcoma, GCT
Widened pubic symphysis: bladder exstrophy, infection, mets, trauma, pregnancy
Widened teardrop in hip: infection, trauma, pigmented villonodular synovitis (erosions, preserved joint space), synovial osteochondromatosis (multiple calcified loose bodies in jt, mimics PVNS if noncalcified), AVN
Protrusio acetabuli: RA, trauma, Paget’s, osteomalacia, AS, IBD – PROT A
Femoral head AVN: alcohol, SCD, exogenous steroids or radiation, pancreatitis, pregnancy, trauma, infection, Caisson, LCP, epiphyseal dysplasia, Gaucher’s (hepatosplenomegaly, osteopenia, AVN, Erlenmeyer flask) – ASEPTIC LEG
Medial tibial spur: osteochrondroma, Blount’s disease, trauma
Dense metaphyseal lines: growth recovery lines, lead, healing rickets, scurvy
Erlenmeyer flask: craniometaphyseal dysplasia, hemoglobinopathies including SCD and thalassemia (marrow hyperplasia, hair-on-end skull, Erlenmeyer flask, extramedullary hematopoeisis), osteopetrosis, Niemann-Pick, Gaucher’s - CHONG
Gracile bones: NF, immobilization, muscular dystrophy, JRA, OI, dysplasias – NIMROD
Bowed bones: rickets, NF, OI, FD
Soft bone: Paget’s, osteogenesis imperfecta, osteomalacia, fibrous dysplasia
Osteopenia: steroids, osteoporosis, osteomalacia, multiple myeloma
Epiphysis: chondroblastoma, GCT (after physis closure), EG, chondrosarcoma
Metaphysis: osteosarcoma, parosteal sarcoma, chondrosarcoma, fibrosarcoma, NOF, GCT (before physis closure), SBC, ABC, osteochondroma
Diaphysis: myeloma, Ewing’s, reticulum cell sarcoma
Metadiaphyseal: fibrosarcoma, fibrous dysplasia, enchondroma, osteoid osteoma, chondromyxoid fibroma
Soft tissue mass: MFH, lipoma, liposarcoma, hemangioma, synovial sarcoma, nerve sheath tumor, mets, hematoma, abscess, rhabdosarcoma, leiomyosarcoma, myositis ossificans, aneurysm
Soft tissue calcification: tumoral calcinosis, synovial osteochondromatosis, ST tumor, scleroderma, dermatomyositis, myositis ossificans progressiva, HPT, metastatic calcifications, CPPD, calcium hydroxyapatite deposition, hematoma, vascular
Tendon rupture: steroids, RA, DM, HPT, gout
Heel pad thickening: >25mm, myxedema, acromegaly, dilantin, callus, obesity, peripheral edema - MADCOP
Periprosthetic lucency: loosening, particle disease, infection
Massive osteolysis: palmar fibromatosis (Dupuytren’s contracture), Gorham’s disease (regional lysis by angiomatous tissue, tapering of remaining bone, ST atrophy), mets, aggressive primary bone or ST tumor, infection