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(BQ) Part 1 book Diagnostic imaging orthopaedics presents the following contents: Rotator cuff, biceps tendoni anchor, osseous structures, osseous trauma , distal radioulnar join, triangular fibrocartilage complex, overuse syndromes and muscle trauma, carpal fractures,...
IAGNOSTIC IMAGING David W Stoller, MD, FACR Director, California Advanced Imaging and MRI California Pacific Medical Center Director, National Orthopaedic Imaging Associates San Francisco, California Director, Musculoskeletal MRI California Pacific Medical Center Phillip F J.Tirman, MD Director, California Advanced Imaging California Pacific Medical Center Director, National Orthopaedic Imaging Associates San Francisco, California Director, Musculoskeletal MRI California Pacific Medical Center Miriam A Bredella, MD Department of Radiology University of California San Francisco San Francisco, California Salvador Beltran, MD Medical Illustrator Robert M Branstetter Ill, MD Diversified Radiology of Colorado Denver, Colorado Simon C P Blease, MD, FRCR Honorary Senior Clinical Lecturer University of Bristol United Kingdom AM1 RSYS" A medical reference publishing company AM I RSYS" A medical r e f e r e n c e publishing company First Edition Second Printing -June2004 Text - Copyright David W Stoller MD 2004 Drawings - Copyright A m i r s y s Inc 2004 Compilation - Copyright Amirsys Inc 2004 rights reserved No part o f this publication may be reproduced, stored in a retrieval system, or transmitted, in any f o r m or media or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from Amirsys I n c All Composition by Amirsys I n c , Salt Lake City, Utah Printed by F r i e s e n s , Altona, Manitoba, Canada ISBN: 0-7216-2920-2 Notice and Disclaimer The information in this product ("Product") is provided as a reference for use by licensed medical professionals and no others It does not and should not be construed as any form of medical diagnosis or professional medical advice on any matter Receipt or use of this Product, in whole or in part, does not constitute or create a doctor-patient, therapist-patient, or other healthcare professional relationship between Amirsys Inc ("Amirsys") and any recipient This Product may not reflect the most current medical developments, and Amirsys makes no claims, promises, or guarantees about accuracy, completeness, or adequacy of the information contained in or linked to the Product The Product is not a substitute for or replacement of professional medical judgment Amirsys and its affiliates, authors, contributors, partners, and sponsors disclaim all liability or responsibility for any injury andlor damage to persons or property in respect to actions taken or not taken based on any and all Product information In the cases where drugs or other chemicals are prescribed, readers are advised to check the Product information currently provided by the manufacturer of each drug to be administered to verify the recommended dose, the method and duration of administration, and contraindications It is the responsibility of the treating physician relying on experience and knowledge of the patient to determine dosages and the best treatment for the patient To the maximum extent permitted by applicable law, Amirsys provides the Product AS IS AND WlTH ALL FAULTS, AND HEREBY DISCLAIMS ALL WARRANTIES AND CONDITIONS, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING BUT NOT LIMITED TO, ANY (IF ANY) IMPLIED WARRANTIES OR CONDITIONSOF MERCHANTABILITY,OF FITNESS FOR A PARTICULAR PURPOSE, OF LACK OF VIRUSES, OR ACCURACY OR COMPLETENESS OF RESPONSES, OR RESULTS, AND OF LACK OF NEGLIGENCE OR LACK OF WORKMANLIKE EFFORT ALSO, THERE IS NO WARRANTY OR CONDITION OF TITLE, QUIET ENJOYMENT, QUIET POSSESSION, CORRESPONDENCE TO DESCRIPTION OR NON-INFRINGEMENT, WITH REGARD TO THE PRODUCT THE ENTIRE RISK AS TO THE QUALITY OF OR ARISING OUT OF USE OR PERFORMANCE OF THE PRODUCT REMAINS WlTH THE READER Amirsys disclaims all warranties of any kind if the Product was customized, repackaged or altered in any way by any third party Library of Stoller, Congress Cataloging-in-Publication Data David W Diagnostic imaging, orthopaedics / David W Stoller, Phillip F.J Tirman, Miriam A B r e d e l l a ;S a l v a d o r Beltran, medical illustrator.1st ed p ;cm I n c l u d e s bibliographical r e f e r e n c e s and index I S B N 0-7216-2920-2 Musculoskeletal s y s t e m - R a d i o g r a p h y - A t l a s e s Diagnostic imaging-Atlases [ D N L M : Musculoskeletal S y s t e m - r a d i o g r a p h y - A t l a s e s Diagnostic I m a g i n g - m e t h o d s - A t l a s e s Orthopedic Procedures-methods-Atlases WE 17 S875d 20041 I Title: Orthopaedics 11 Tirman, Phillip F J 111 B r e d e l l a , Miriam A IV Title To m y cherished son, GrifFn, and m y lovely wife, Marcia for their extraordinary love and support & to the exceptional team of Phillip F J Tirman, MD, Miriam A Bredella, MD, Salvador Beltran, MD, Robert M Branstetter III, MD and Simon C P Blease, MD, FRCR whose cohesive partnership on the production of this book truly represented a force of nature D WS To m y father, the late Robert M Tirman, MD who was an inspiration To Collin and Skye, m y children and Linda whose patience and understanding was truly appreciated To m y parents, Erika and Lothar, and to Harold, for their love and encouragement M.A.B CONTRIBUTORS David W Stoller, MD, FACR Director, California Advanced Imaging and MRI California Pacific Medical Center Director, National Orthopaedic Imaging Associates San Francisco, California Director, Musculoskeletal MRI California Pacific Medical Center Phillip F J Tirman, M D Director, California Advanced Imaging California Pacific Medical Center Director, National Orthopaedic Imaging Associates San Francisco, California Director, Musculoskeletal MRI California Pacific Medical Center Miriam A Bredella, M D Department of Radiology University of California San Francisco San Francisco, California Salvador Beltran, M D Medical Illustrator Robert M Branstetter Ill, M D Diversified Radiology of Colorado Denver, Colorado Simon C F! Blease, MD, FRCR Consultant Musculoskeletal Radiologist Med-Tel International Corporation McLean, Virginia Honorary Senior Clinical Lecturer University of Bristol United Kingdom Jana M Crain, M D Medical Director National Orthopaedic Imaging Associates Niku F! Wasudev, M D Musculoskeletal MRI National Orthopaedic Imaging Associates James 0.Johnston, M D Professor Orthopaedic Oncology University of California, San Francisco Director Orthopaedic Oncology Kaiser South San Francisco vii DIAGNOSTIC IMAGING: ORTHOPAEDICS The imaging, orthopedics and sports medicine communities have been waiting a long time for a new "Stoller" We at Amirsys and Elsevier are proud to present a precedent-setting, image- and graphics-packed series that debuts with a brand-new work by David Stoller and colleagues This splendid work represents the textbook of the twenty-first century: Not your old-fashioned, dense prose exposition with comparatively few images The unique bulleted format of the Diagnostic Imaging books allow our authors t o present approximately twice the information and four times the images per diagnosis, compared to the old-fashioned traditional prose textbook These richly illustrated books will cover all major body areas and follow a similar format The same information is in the same place: Every time! A welcome innovation is the new visual differential diagnosis "thumbnail" that provides at-a-glance looks at entities that can mimic the diagnosis in question "Key Facts" boxes provide a succinct summary for quick, easy review In short, this is a product designed with you, the reader, in mind Today's typical practice settings demand efficiency i n both image interpretation and learning We think you'll find the Diagnostic Imaging format a highly efficient and wonderfully rich resource Enjoy! Anne G Osborn, MD Executive Vice-President and Editor-in-Chief, Amirsys H Ric Harnsberger, MD Chairman and CEO, Amirsys Inc David W Stoller, MD, FACR Editor Diagnostic Imaging Orthopaedics OSTEOARTHRITIS, HIP o Limited ability to sit, stand or walk o Symptoms worse in mornings & exacerbated by axial loading or weight-bearing activity General Features General path comments o Relevant anatomy Hyaline cartilage - resists mechanical stress (elastic) Subchondral plate + calcified cartilage = less compressible than articular cartilage Synovial fluid - produced by synoviocytes of synovial membrane (provides nutrients & viscosity + elasticity for shock absorption) Etiology o Articular cartilage overload o Primary (idiopathic) vs secondary (pre-existing joint disorder) o Inflammation contributes to cartilage degeneration o Pathophysiologic changes also occur in synovial fluid, subchondral bone + capsular tissue o Cartilage may also be damaged by a metabolic process Epidemiology: 23% incidence at 55-74 years o Pain & loss of internal rotation Demographics Age: Usually > 55 years Gender: OA of hips > in males (OA knees > females) Natural History & Prognosis Incidence of OA increases with age Clinical stabilization vs progressive course Gait abnormalities Femoroacetabular impingement in the young patient may rapidly progress to advanced OA changes Unilateral involvement is common Treatment Conservative o NSAIDs o Physical therapy o Intraarticular steroids in acute episodes o Intraarticular hyaluronate injections Surgical o Total hip arthroplasty Gross Pathologic & Surgical Features Articular cartilage o Fibrillation - fragmentation Pressure erosion Joint space narrowing: Weight-bearing zones Subchondral cysts Sclerosis, osteophytes & labral tear End-stage ankylosis Consider Inflammatory OA with reactive subchondral edema involving both sides of joint Younger patient may present with femoroacetabular impingement as precursor to OA Primary process involves chondral degeneration as seen on FS PD FSE (small FOV) coronal images Microscopic Features Osteonecrosis of subchondral bone Hypervascularity Osteoblastic activity Trabecular thickening Subchondral cysts (detritic cysts) Myxoid material o Proteoglycans o Articular cartilage fragments o Metaplastic cartilage Chondrocyte replication Decreased concentration of hyaluronic acid Staging, Grading or Classification Criteria Grade I: Chondral inhomogeneity Grade 11: Inhomogeneity + discontinuity of chondral surface & hypointensity of femoral headlneck on TlWI Grade 111: Grade I1 + irregular cortical morphology of femoral head/acetabulum, cystic changes & indistinct zone between femoral headlacetabulum Grade IV: Addition of femoral head deformity Presentation Most common signs/symptoms: Joint pain Clinical profile o Insidious onset groin + thigh pain o k Gluteal pain radiation o Stiffness [SELECTED REFERENCES DeLee JC et al: Orthopaedic sports medicine Principles and practice Hip and pelvis vol 2nd ed Philadelphia PA, WB Saunders, (25):1443-62, 2003 Fitzgerald RH et al: Orthopaedics Arthritis of the hip St Louis MO, Mosby, (6-8):869-76,2002 Meyers S: Synovial fluid markers in osteoarthritis Rheum Dis Clin North Am 25:433, 1999 Buckwalter J et al: Articular cartilage: Degeneration and osteoarthritis, repair, regeneration, and transplantation Instr Course Lect Rosemont IL, WB Saunders, 487, 1998 Vingard E et al: Sports and osteoarthritis of the hip An epidemiological study Am J Sports Med 21:195, 1993 Schumacher JR: Secondary osteoarthritis: Osteoarthritis: Diagnosis and management Philadelphia PA, WB Saunders, 367-98, 1992 Haller J et al: Juxtaacetabular ganglionic (or synovial) cysts: CT and MR features J Comput Assist Tomogr 13:976, 1989 OSTEOARTHRITIS, HIP I IMAGE GALLERY (Left) Coronal graphic shows focal femoral head chondral erosion (Right) Coronal graphic shows degenerative acetabular labrurn associated with subchondral acetabular cysts (Left) Surgical pathology shows intact labrum in a degenerative hip specimen (Right) Surgical pathology shows chondral erosion of articular surface of acetabulurn (lunate surface) Typical (Left) Coronal FS PD FSE MR shows superior joint space narrowing with full thickness acetabular chondral loss (arrow) and subchondral marrow edema Osteophytes are present at the femoral headheck junction (Right) Coronal FS PD FSE MR shows narrowing of the superior joint space with loss of both femoral and acetabular articular cartilage Subchondral cysts, (open arrow) labral tear, and osteophytes (arrows) are shown LOOSE BODIES, HIP Coronal graphic shows loose body lodged within the acetabular fossa Axial NECT shows osseous loose bodies within the acetabular fossa Particulate matterldebris typically cannot be visualized o Causative etiology or donor site can be identified Fractures (acetabular, osteochondral, femoral head) Osteoarthritis Avascular necrosis (AVN) or Legg-Calve-Perthes Abbreviations and Synonyms Free fragments, joint mice, rice bodies Definitions Free-floating or adherent intraarticular body CT Findings NECT o Excellent bony detail o Multi-planar capability o Chondral fragments cannot be visualized o Arthrography will increase sensitivity for non-ossified or non-calcified loose bodies o Associated fractures/dislocations o Causative etiology often identified Fracture NI Osteoarthritis (OA) AVN rn Osteochondral lesion General Features Best diagnostic clue: Low to intermediate signal intensity focus within joint capsule on TI & T2WI Location o Acetabular fossa common location o Other intracapsular locations including zona orbicularis Size: Variable from small chondral to larger osteochondral fragment Morphology: Roundloval to elongated MR Findings Radiographic Findings Radiography o Anteroposterior + frog-leg views o Usually insensitive, even for bony or calcified bodies o Chondral loose bodies (non-radiopaque) cannot be visualized TlWI o Hypointense to intermediate fragment Less common - osteochondral fragment with marrow fat signal + hypointense sclerotic border T2WI Hypointense to intermediate on T2WI mmw?4jl DDx: Loose Bodies, Hip Osteoarthritis ' + Cor PD FSE MR Cor FS PD MR Cor T1 Arthro LOOSE BODIES, HIP Key Facts Imaging Findings Best diagnostic clue: Low to intermediate signal intensity focus within joint capsule on T1 & T2WI Acetabular fossa common location Hypointense to intermediate on T2WI Defect in chondral surface of femoral head or acetabulum Top Differential Diagnoses Osteoarthritis Synovial Disorders Acetabular Labral Tears Artifacts Osteoarthritis PVNS Synovial chondromatosis/osteochondromatosis Clinical Issues Pain secondary to retained material in acetabular fossa Clicking Snapping Popping Increased symptoms with activity Diagnostic Checklist Match loose body with donor site if possible Pathology Trauma - commonly 2" to posterior dislocation + acetabular fracture o o o o Hyperintense adjacent synovial fluid f Adherent to synovium Requires FS PD FSE or STIR Donor site evaluation Defect in chondral surface of femoral head or acetabulum TI C+ o MR arthrography Osseous, calcified, chondral, osteochondral bodies visualized Particulate mattertdebris demonstrated Donor sites shown Less sensitive to subchondral changes or basal chondral degeneration Ultrasonographic Findings Real Time o Effusions help in searching for loose bodies o Loose bodies = small hyperechoic foci in a hypo or anechoic background (effusion) o Loose bodies in children with non-ossified epiphyses o Particulate debris - tiny floating hyperechoic foci (inflammatory arthritis, infection) o Chondral fragments: Hyperechoic, polygonal in shape o Osseous or calcified loose bodies: Hyperechoic - may produce shadowing Imaging Recommendations Best imaging tool: MR for spectrum of chondral to osteochondral fragments, donor site location + associated subchondral changes Protocol advice: T1 or PD + FS PD FSE or STIR in coronal, axial f sagittal planes Osteoarthritis Joint space narrowing Osteophytes Subchondral sclerosis Cystic changes Chondral degeneration anterosuperior femoral head or acetabulum Synovial Disorders Rheumatoid - synovial proliferation Chondromatosis/osteochondromatosis - cartilaginous metaplasia Pigmented villonodular synovitis (PVNS) - periarticular erosions + synovial proliferation + hemosiderin Inflammatory osteoarthritis - synovitis k reactive subchondral marrow edema Acetabular Labral Tears Catching, locking, clicking and pain Associated with femoroacetabular impingement osteoarthritis Bucket-handle labral tears + Artifacts Physiologic nitrogen Iatrogenically introduced air in MR arthrography Microscopic post-surgical metallic susceptibility artifact (MRI) PATHOLOGY General Features General path comments o Relevant anatomy Inelastic fibrous capsule of hip - reinforced by iliofemoral, pubofemoral + ischiofemoral ligaments Zona orbicularis = deep circular fibers from ischiofemoral ligament (may be mistaken for labrum arthroscopically) Fovea capitis of femoral head = no articular cartilage surface Etiology o Trauma - commonly 2"to posterior dislocation + acetabular fracture o Osteoarthritis o PVNS o Synovial chondromatosis/osteochondromatosis - LOOSE BODIES, HIP o Crystal induced arthropathies Gout Calcium pyrophosphate dihydrate deposition (CPPD) o Rheumatoid arthritis o Infectionlseptic arthritis o AVN o Legg-Calvk-Perthes Epidemiology o Variable based on etiology o Osteoarthritis - most common source of chondral debris Gross Pathologic & Surgical Features Osseous fracture fragment Acetabular fractures Osteochondral fractures Chondral fractures Traumatic labral tears + free-floating labral fragments Chondral degeneration + sloughing Svnovial ~roliferations Proteinaceous debris in setting of infection Loose bodies may be identified in acetabular fossa, recesses around zona orbicularis 92 Microscopic Features Proliferation of concentric layers of new cartilage + bone Laminated appearance Cartilaginous metaplasia in osteochondromatosis DIAGNOSTIC CHECKLIST Consider Match loose body with donor site if possible FS PD FSE or STIR images to provide hyperintensity of joint fluidleffusion to facilitate loose body identification Evaluate for underlying joint disorder with patient history of clicking, locking, trauma Presentation Most common signs/symptoms: Locking or catching Clinical profile o Pain secondary to retained material in acetabular fossa o Clicking o Snapping o Popping o Increased symptoms with activity Demographics Age: Older adults most commonly affected (due to association with OA) Gender: M slightly > F Natural History & Prognosis Most loose bodies remain in joint unless surgically removed May enlarge over time Rarely resorb Synovitis/debris o Treated conservatively o Improves when underlying pathology improves Treatment Conservative for bodies secondary to underlying joint disorder o Synovitis o + Debris - particulate o Infection - antibiotics to avoid joint destruction Surgical Most loose bodies arthroscopically removed Osseous fracture fragments Ossified or calcified loose bodies Chondral/osteochondral fragments - reattach to donor site or remove Chondromatosislosteochondromatosis PVNS Free floating labral fragment 10, 11 12 13 Kramer J et al: MR arthrography of the lower extremity Radiol Clin of N America 40(5):1211-32,2002 Bencardino JT et al: Imaging of hip disorders in athletes Radiol Clin of N America 40(2):267-87,2002 Attarian DE et al: Observations on the growth of loose bodies in joints Arthroscopy 18(8):930-4,2002 Resnick D: Diagnosis of bone and joint disorders Degenerative disease of extraspinal lesions 4th ed Philadelphia PA, WB Saunders, 1351-52, 2002 Van Holsbeeck MT et al: Musculoskeletal ultrasound 2nd ed St Louis MO, Mosby, 265-8, 2001 McCarthy JC et al: The adult hip Alternative to arthroplasty vol Iowa City IA, Lippincott-Raven, (43):721-36, 1998 Stoller DW: Magnetic resonance imaging in orthopaedics and sports medicine 2nd ed Philadelphia PA, WB Saunders, 802-12, 1997 McCarthy JC et al: The role of hip arthroscopy in the diagnosis and treatment of hip disease Orthopaedics 18(8):753-6,1995 Edwards DJ et al: Diagnosis of the painful hip by magnetic resonance imaging and arthroscopy J Bone Joint Surg 77B(3):374-6, 1992 Berquist TH et al: Imaging of orthopaedic trauma The pelvis and hips 2nd ed New York NY, Raven Press, 298-9, 1992 Hawkins RB: Arthroscopy of the hip Clin Orthop 24944-7, 1989 Harris WH: Etiology of osteoarthritis of the hip Clin Orthop 213:20-33, 1986 Burman MS: Arthroscopy or the direct visulization of joints J Bone Joint Surg 4:669-95, 1931 I LOOSE BODIES, HIP (Left) Axial T2WI MR shows cartilaginous loose body (arrow) in anterior left hip capsule (Right) Axial graphic shows anterior capsule loose body Typical (Left) Coronal graphic shows synovial chondromatosis within the acetabular fossa (Right) Axial PD/lntermediate MR shows synovial chondromatosis as hypointense defects (arrow) within the left hip joint effusion Typical (Left) Coronal T I C+ MR (MR arthrography) shows inferior capsule loose body (arrow) associated with adherent synovium (Right) Axial FS PD FSE MR shows small corticated loose body (arrow) anterior to the femoral neck I I RHEUMATOID ARTHRITIS, HIP Coronal graphic shows multiple bilateral symmetric chondral and subchondral erosions in juvenile chronic arthritis Coronal T l Wl MR shows bilateral epiphyseal erosions in juvenile chronic arthritis Radiographic Findings Radiography o Negative in early stages o Loss of joint space (chondral loss) o Progressive worsening of joint space loss o Juxta-articular osteoporosis o Soft tissue swelling o Loss of subchondral plate o Erosion - bare areas/capsular insertions o Subchondral cysts usually c cm o Axial migration of femoral head o Protrusio acetabuli - medial femoral head cortex medial to ilioischial line Abbreviations and Synonyms RA, inflammatory arthritis, rheumatoid disease, juvenile chronic arthritis Definitions Systemic autoimmune inflammatory disorder of unknown etiology primarily affecting synovial membranes + articular surfaces General Features Best diagnostic clue: Effusion and synovial proliferation Location o Femoral head o Acetabulum o Joint capsule Size o Diffuse involvement of femoral head o Entire joint at risk Morphology o Concentric loss of joint space o Protrusio deformity (medial displacement of femoral head) CT Findings NECT o Sensitive to subchondral erosions o Hypodense joint effusion o Joint space narrowing o & Sclerosis, osteophytosis - superimposed osteoarthritic change MR Findings TlWI o Hypointense joint effusion o Hypointense subchondral erosions o Hypointense mass - fluid in iliopsoas bursa o Hypointense acetabular + femoral head edema DDx: Rheumatoid Arthritis, Hip Cor FS PD MR AVN DDH Cor ~1 WI MR Cor T I WI MR Labral Tear BD Cor FS PD MR Sag FS PD MR RHEUMATOID ARTHRITIS, HIP Key Facts Imaging Findings Best diagnostic clue: Effusion and synovial Concentric loss of joint space Protrusio deformity (medial displacement of femoral Inhomogeneity of effusions, synovium + debris relative to hyperintense fluid on T2WI Top Differential Diagnoses Femoroacetabular Impingement Avascular Necrosis (AVN) Developmental Dysplasia of the Hip (DDH) Labral Tears Pigmented Villonodular Synovitis (PVNS) T2WI o Hyperintense joint effusion o Capsular distension (joint capsule) o ~emineralization(juxta-articular bone loss) with marrow hyperintensity on FS PD FSE or STIR o AttenuationJloss of subchondral plate (normally hypointense) o Intermediate to hyperintense subchondral cysts without sclerotic reactive interface o Femoral + acetabular erosions not confined to any specific quadrant (vs osteoarthritis) o Hyperintense marrow edema o Inhomogeneity of effusions, synovium + debris relative to hyperintense fluid on T2WI T1 C+ o Intravenous contrast to enhance pannus tissue Map extent + distribution of synovial involvement Imaging Recommendations Best imaging tool o MR Detection of synovial pannus, erosions, cartilage loss, small subchondral cysts + marrow edema distribution Protocol advice: TI, FS PD FSE or STIR + FS T1 C+ in the coronal, axial, sagittal planes Femoroacetabular Impingement Findings of osteoarthritis in non-dysplastic hips in younger patient population Repetitive microtrauma 2" impingement of femoral head against acetabulum Hyperintense signal (T2WI) of lateral femoral head + acetabular rim + labral tears & chondral defects Avascular Necrosis (AVN) Wedge-shaped subchondral bone infarct Articular cartilage intact at presentation Double line sign on T2WI in 80% Pathology Unknown etiology Bilateral, symmetrical joint involvement Hip joints involved later in disease process Inflammatory condition of synovial tissue Faulty immune response Clinical Issues Most common signslsymptoms: Hip pain + stiffness Insidious onset Joint swelling, tenderness to palpation Pain with activelpassive range of motion (ROM) Diagnostic Checklist Intravenous contrast to enhance pannus Developmental Dysplasia of the Hip (DDH) Acetabular dysplasia - shallow acetabulum Lateral acetabular rim syndrome findings similar to femoroacetabular impingement in non-dysplastic hips Identified on anterior coronal images Labral Tears Linear hyperintensity f abnormal morphology on T2WI f Paralabral cyst communication with tear Pigmented Villonodular Synovitis (PVNS) Proliferation of synovial lining Hemosiderin-containing Inhomogeneous signal on T2WI typically involving the medial capsule adjacent to femoral headlneck junction Hemosiderin - increased susceptibility on T2* gradient echo Synovial Chondromatosis Multiple cartilaginous or osseous intraarticular loose bodies Related to synovial metaplasia Effusion + pain + restricted joint motion Pyrophosphate Arthropathy CPPD (calcium pyrophosphate dihydrate crystal deposition disease) Calcified labrum Subchondral cysts Crystal deposition in chondral surfaces May cause or accelerate osteoarthritis Seronegative Arthritis Asymmetric Osteosclerosis Osseous proliferations Ankylosis Inflammatory Systemic Connective Tissue Diseases Systemic lupus erythematosus RHEUMATOID ARTHRITIS, HIP Scleroderma Polymyositis & dermatomyositis PATHOLOGY General Features General path comments o Relevant anatomy Subchondral plate - supports articular cartilage Articular cartilage = hyaline Joint capsule = fibrous + synovial lining Synovial fluid - diffusion of nutrients to articular cartilage Genetics: Genetic predisposition - HLA-D antigen Etiology o Unknown etiology o Bilateral, symmetrical joint involvement o Hip joints involved later in disease process o Inflammatory condition of synovial tissue o Faulty immune response o Arthrotropic parvoviruses & lentiviruses - induce T4 helper cells + cytokine-medicated oligoclonal B cell resDonse (InG + InM rheumatoid factors) Epidemiology: Prevalence of RA = 1Yo of population ~ qh - - Gross Pathologic & Surgical Features Synovial inflammation Pannus Tendon tears/ruptures Articular cartilage erosions Superior + medial protrusion of hip into pelvis Synovial cysts - subchondral Microscopic Features Hyperplasia of synovial cells o Redundant synovial folds, villae + masses Lymphocytes + plasma cells infiltrate synovial membrane Fibrinous exudates Presentation Most common signs/symptoms: Hip pain + stiffness Clinical profile o Insidious onset o of criteria for diagnosis Morning stiffness > hr., or more joints, hand joints, symmetric, + Rh factor, nodules, radiographic changes o Malaise, weakness, weight loss, myalgias, fever o Joint swelling, tenderness to palpation o Pain with active/passive range of motion (ROM) o Rheumatoid factor Serum IgM antibody - 70% Directed against Fc fragment of IgG 30% rheumatoid negative o Serum ANA (antinuclear antibodies) - 30% Demographics Age o Adults - 25 to 60 years o Peak incidence 40-60 years Gender: F:M > 3:l Natural History & Prognosis Slowly progressive disease with intermittent "flare-ups" + Indolent course Joint destruction Complications o Joint effusions - capsular distention - pain o Large synovial cysts o Tendinous tears/disruptions o Cartilaginous destruction - joint obliteration o Osseous destruction o Fibrous/bony ankylosis o AVN (secondary to steroid use) Treatment Conservative o Decrease inflammation, delay joint destruction + preserve function o Pharmacotherapy Decrease inflammation NSAIDs; immune mediating agents o Physical therapy Heat, maintain ROM, strength, flexibility Surgical o Synovectomy (controversial) o Total hip arthroplasty - end stage disease Consider Intravenous contrast to enhance pannus FS PD FSE or STIR for visualization of pannus + subchondral edema Dablov G: Miscellaneous nontraumatic disorders: Cambell's operative orthopaedics 10th ed Philadelphia PA, Mosby, 905-13, 2003 Resnick D: Degenerative disease of extraspinal lesions: Diagnosis of bone and joint disorders 4th ed Philadelphia PA, WB Saunders, 891-939, 2002 Van Holsbeeck MT et al: Musculoskeletal ultrasound 2nd ed St Louis MO, Mosby, 373-91, 2001 Mettler FA et al: Skeletal system: Essentials of nuclear medicine imaging 4th ed Philadelphia PA, WB Saunders, 326-9, 1998 Stoller DW: Magnetic resonance imaging in orthopaedics and sports medicine 2nd Ed Philadelphia PA, Lippincott Williams, 187-91, 1997 Anderson RJ: Rheumatoid arthritis: Primer on the rheumatic diseases The arthritis foundation 90-5, 1993 Schumacher JR: Secondary osteoarthritis: Osteoarthritis-diagnosis and management Philadelphia PA, WB Saunders, 367-98, 1992 Wallace CA et al: Juvenile rheumatoid arthritis: Outcome and treatment for the 1990's Rheum Dis Clin North Am 175391-906, 1991 RHEUMATOID ARTHRITIS, HIP I IMAGE GALLERY OSTEOMYELITIS, HIP Coronal graphic shows synovitis and infectious nidus of the femoral head with reactive marrow edema involving both the acetabulum and femoral head Coronal FS PD FSE MR shows septic right hip with hyperintensejoint effusion and capsular distension Changes delayed 10-14 days after onset of fever Soft tissue edema/swelling Focal lucency to frank destruction of bone Periosteal elevation + underlying lucency (subperiosteal abscess) o Intramedullary abscess - focal lucency tract to cortical surface o Sequestration (necrotic fragments) + involucrum (periosteal bone) as parosteal ossification o Joint effusion - widening of affected hip joint o o o o Abbreviations and Synonyms Acute hematogenous osteomyelitis, chronic osteomyelitis + Definitions Acute hematogenous osteomyelitis in pediatric patient & chronic post-traumatic osteomyelitis in adult patient CT Findings General Features Best diagnostic clue: Bone marrow hyperintensity, erosion + sinus tract on T2WI Location o Bone marrow in hematogenous osteomyelitis o Osteitis f marrow involvement in secondary (trauma or surgery) osteomyelitis Size: Variable from epiphyseal involvement to diaphyseal + soft tissue involvement Morphology: Focal, Brodie's abscess or larger area of medullary or cortical destruction Radiographic Findings Radiography o Insensitive for early osteomyelitis DDx: Osteomyelitis, Hip Avid Cor PD FS MR Sag T7 WI MR NECT o Early bone destruction o Assessment of cortical + trabecular bone detail o Periosteal elevation, cortical destruction, intramedullary abscess + sinus tracts o Joint effusions = hypodense CECT o Infected regions enhance o Soft tissue complications: Abscesses enhance peripherally, sinus tracts enhance wmw MR Findings TlWI o Hypointense marrow edema + cortical destruction o Hypointense reactive joint effusion o Hypointense soft tissue abscess o Tract from skin to cortex bt yositis ~ s r i l i c Sag FS PD MR Cor T l W l MR Cor FS PD MR - OSTEOMYELITIS, HIP Key Facts Chronic osteomyelitis = most common form of osteomyelitis in adult & 2' to trauma Hematogenous seeding Direct contamination 'pread Imaging Findings Best diagnostic clue: Bone marrow hyperintensity, erosion + sinus tract on T2WI Sequestrum: Hypointense on TI + T2WI Involucrum (periosteal reaction): Hypointense on T1 EX T2WI Clinical Issues ~ o scommon t signs/symptoms: Pain Fever Top Differential Diagnoses Transient Osteoporosis of the Hip (TOH) Avascular Necrosis (AVN) Cellulitis Septic Arthritis Amyloid Diagnostic Checklist Identify marrow edema as well as associated extension through cortex + soft tissue tract Axial images to identify hypointense sequestrum Pathology Staph aureus = most common infecting organism in all age groups Double-line sign on T2WI in 80% Fat signal in ischemic lesion in earlier stages f Hyperintense marrow edema extending to femoral neck on T2WI o Hypointense to intermediate signal in metaphysis/diametaphysis in child T2WI o Hyperintense marrow involvement o Hyperintense intraosseous abscess o Cortical destruction: Intermediate to hyperintense o Cloaca (periosteal opening): Focal hyperintensity in hypointense periosteum o Sinus tract: Intermediate to hyperintense o Brodie's abscess (round abscess cavity representing a chronic pyogenic infection): Hyperintense + hypointense sclerotic rim o ~ellulitis:Reticulated subcutaneous hyperintensity o Myositis: Hyperintense muscle + enlargement TI C+ o Enhancement Bone marrow - inflammation = Abscess - peripheral enhancement within medullary canal or soft tissue (thick wall) ~nhancementperipheral to sequestrum Cortical erosion/destruction - + enhancement Sinus tract - peripheral enhancement Sequestrum: Hypointense on T1 + T2WI ~n