Bone and Joint Disorders E-Book

Francis A. Burgener

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 543

Veröffentlichungsjahr: 2005

Beschreibung

The second edition of Bone and Joint Disorders, derived from the critically acclaimed series Differential Diagnosis in Conventional Radiology, provides the essential information you need to make the conventional x-ray an effective tool in diagnosing disorders affecting the bones and joints. The book is organized according to classes of radiologic findings, with separate chapters addressing the differential diagnosis of osteopenia, osteosclerosis, trauma and fractures, arthritis, and tumors, as well as the differential diagnosis of lesions specific to anatomic sites. Concise but comprehensive tables outline key information about findings and etiology, and provide additional commentary on pertinent clinical data, such as common locations, frequency, and prevalence of the described disease or disorder. Highlights: Organizes information according to classes of radiologic findings, mirroring the situation encountered in clinical practice Uses easy-to-reference tables that classify findings, correlate differential diagnoses, and provide key adjunct clinical information to help in confirm the diagnosis Includes more than 1,000 images and illustrations that are captioned by succinct descriptions, pinpointing key characteristics of disorders Features completely rewritten chapters, "Localized Bone Lesions" and "Joint Diseases," with all new radiographs, and a greatly expanded chapter, "Trauma and Fractures," with many new and improved radiographs and schematic diagrams Authoritative and comprehensive, Bone and Joint Disorders is an outstanding professional reference for the radiologist who must develop diagnoses and differential diagnoses of bone and joint disorders. This book is also of interest to residents preparing for their specialist examinations.

Leseprobe

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Preface

Conventional radiography remains the backbone of musculoskeletal radiology despite the advent of newer and more exciting imaging techniques such as computed tomography, magnetic resonance imaging, and, most recently, positron emission tomography. In contrast to many of these newer methods, conventional radiography is practiced not only by radiologists but also by a large number of clinicians and surgeons. With each examination, one is confronted with radiologic findings that require interpretation in order to arrive at a general diagnostic impression and a reasonable differential diagnosis. To assist the film reader in attaining this goal, this book is based upon radiographic findings unlike most other textbooks in radiology that are disease oriented. Since many diseases present radiographically in a variety of manifestations, some overlap in the text is unavoidable. To minimize repetition the differential diagnosis of a radiographic finding is presented in tabular form whenever feasible. Most tables do not only list the various diseases that my present radiologically in a a specific pattern, but also describe in succinct form other characteristically associated radiographic findings and pertinent clinical data. Radiographic illustrations and drawings are included to demonstrate visually the radiographic features under discussion.

The transition from film to digital radiography had the greatest impact on conventional radiology since the publication of the last edition. This change, however, did not affect the way radiologic diagnoses are ascertained. Since the publication of the last edition the name of a few disorders has changed (e. g., histiocytosis X to Langerhans cell histiocytosis) and a few disease are newly recognized (e. g., femoroacetabular impingement). These facts were taken into account in the new edition. The chapters “Localized Bone Lesions“ and “Joint Diseases“ were completely rewritten and newly illustrated, since I took them over from Dr. Kormano. The chapter “Trauma and Fractures“ also under went a major overhaul by the inclusion of specific fracture sites. In the remaining chapters of the book the text was updated, many illustrations replaced, and large numbers of new illustrations added.

A changing of the guard has also taken place. Since Dr. Martti Kormano's professional endeavors do no longer include clinical radiology, he felt no longer up the task to update his original contributions to the text. He was however very fortunate to find in Dr. Tomi Pudas a very talented young radiologist to take over the revision of the chapters originally prepared by him.

I hope this new edition will be as well received as its predecessors in the past that were translated into five foreign languages. The concept of an imaging pattern approach in tabular form rather than a disease oriented text was introduced in 1985 with our original edition Differential Diagnosis in Conventional Radiology and has since been adopted by many authors. I feel complimented by the old cliché, “imitation is the sincerest form of flattery.“

This book is meant for physicians with some experience in musculoskeletal radiology who wish to strengthen their diagnostic acumen. It is a comprehensive outline of radio-graphic findings and it should be particularity useful to radiology residents preparing for their specialist examination, especially since the exposure to conventional radiography during their training continuously decreased in the past in favor of newer imaging modalities. Any physician involved in the interpretation of conventional bone radiographic examinations should find this book helpful in direct proportion to his or her curiosity.

It is my hope that this new edition will be as well received as the previous ones by medical students, residents, radiologists, and physicians involved in the interpretation of conventional bone radiographs.

Francis A. Burgener, M. D.

Acknowledgements

It is impossible to thank individually all those who helped to prepare the third edition of this textbook. I wish to acknowledge the staff of our publisher Thieme, in particular Dr. Clifford Bergman and Mr. Gert A. Krüger.

I am deeply indebted to Dr. Gertrud Gollman, Steinach am Attersee, Austria, who translated the last edition of this text into German and suggested many alterations and corrections, which have been incorporated into this new edition.

My gratitude goes to all the radiologists whose cooperation made available illustrative cases to compliment the original collection or to replace older illustrations. I am indebted to Drs. Steven P. Meyers, Johnny U. V. Monu, and Gwy Suk Seo, all staff members of the University of Rochester Radiology Department, and to the former residents Drs. John M. Fitzgerald and Wael E. A. Saad for providing selected cases.

I wish to express also many thanks to Jeanette Griebel, Iona Mackey, and Marcella Maier for their assistance in preparing the references and to Shirley Cappiello for her general assistance. Last, but not least, I am most grateful to Alyce Norder who left the University and me after 30 years for the richness of the industry. She is the only person capable of deciphering my longhand and, as in the past, did a superb job in typing, editing, and proofreading the manuscript of the new edition of this text. Despite her heavy workload as executive assistant in her new endeavor. Alyce was kind enough to perform this task in her spare time, for which I am greatly appreciative.

Finally I appreciate the support of my wife Therese, who has generously given her precious family time for the preparation of this book.

Francis A. Burgener, M.D.

I would like to express my deepest gratitude to honorary professor Martti Kormano who invited me to carry on his work in this new edition. I continue to admire the massive work that he and Dr. Burgener originally put into the project in the early nineteen-eighties. The hundreds of hours which Dr. Kormano and I have spent together editing this edition have been a great pleasure. It was a fascinating time in my life.

I especially want to thank Drs. Kimmo Mattila and Seppo Koskinen for introducing me to musculoskeletal radiology, and for their extraordinary teaching and support. Many thanks also belong to Drs. Erkki Svedström, Risto Elo, and Peter B. Dean for encouraging me on my way in the field of radiology. The many fascinating discussions I have had with Drs. Seppo Kortelainen and Teemu Paavilainen brought me much delight, on non-radiological topics as much as on professional subjects.

I also express sincere thanks to the staff of the publishers, Thieme, especially to Dr. Clifford Bergman and Mr. Gert Krüger. Finally, much gratitude is due to Mr. Markku Livanaien for his valuable assistance with technical questions, and to Ms. Pirjo Helanko for all her help with general matters. Many other individuals helped in various ways with this project, and though I cannot name them all, I am grateful for their contributions.

Tomi Pudas, M.D.

Contents

1 Osteopenia

Francis A. Burgener

2 Osteosclerosis

Francis A. Burgener

3 Periosteal Reactions

Francis A. Burgener

4 Trauma and Fractures

Francis A. Burgener

5 Localized Bone Lesions

Francis A. Burgener

6 Joint Diseases

Francis A. Burgener

7 Joint and Soft-Tissue Calcification

Martti Kormano and Tomi Pudas

8 Skull

Francis A. Burgener

9 Orbits

Francis A. Burgener

10 Nasal Fossa and Paranasal Sinuses

Francis A. Burgener

11 Jaws and Teeth

Francis A. Burgener

12 Spine and Pelvis

Martti Kormano and Tomi Pudas

13 Clavicles, Ribs, and Sternum

Martti Kormano and Tomi Pudas

14 Extremities

Francis A. Burgener, Martti Kormano, and Tomi Pudas

15 Hands and Feet

Martti Kormano and Tomi Pudas

References

Index

Abbreviations

ABC

aneurysmal bone cyst

AC

acromioclavicular (joint)

ACTH

adrenocorticotropic hormone

AIDS

acquired immune deficiencly syndrome

ALL

acute lymphoblastic leukemia

AML

acute myeloblastic leukemia

ANCA

antineutrophil cytoplasmotic autoantibodies

ANT

anterior

AP

anteroposterior

AV

arteriovenous

AVF

arteriovenous fistula

AVM

arteriovenous malformation

AVN

avascular necrosis

Bx

biopsy

Ca

calcium

CLL

chronic lymphatic leukemia

CNS

central nervous system

CPP

calcium pyrophosphate dihydrate crystals

CPPD

calcium pyrophosphate dihydrate deposition disease

CRMO

chronic recurrent multifocal osteomyelitis

CT

computed tomography

D

disease

DD

differential diagnosis

DDH

development dysplasia of the hip

DIP

distal interphalangeal (joint)

DISH

diffuse idiopathic skeletal hyperostosis

DISI

dorsal intercalated segmental instability

EAC

external auditory canal

EG

eosinophilic granuloma

F

female

HAD

calcium hydroxyapatite crystals

HADD

calcium hydroxyapatite crystal deposition disease

Hb

hemoglobin

HD

Hodgkin disease

HIV

human immunodeficiency virus

Hx

history

IAC

internal auditory canal

IM

intramuscular

IP

interphalangeal (joint)

IV

intravenous

L

left

LCH

Langerhans cell histiocytosis

LE

lupus erythematosus

M

male

MAI

Mycobacterium avium intracellulare

MCP

metacarpophalangeal (joint)

MFH

malignant fibrous histiocytoma

MPS

mucopolysaccharidosis

MR

magnetic resonance

MRI

magnetic resonance imaging

MS

multiple sclerosis

MTP

metatarsophalangeal (joint)

NHL

non-Hodgkin lymphoma

NUC

nuclear medicine

PA

posteroanterior

PATH

pathology

PET

positron emission tomography

PIP

proximal interphalangeal (joint)

PNET

primitive neuroectodermal tumor

PVNS

pigmented villonodular synovitis

RA

rheumatoid arthritis

RBC

red blood cell

RES

reticuloendothelial system

RSD

reflex sympathetic dystrophy

SC

sternoclavicular (joint)

SI

sacroiliac (joint)

SLAC

scapholunate advanced collapse

SLE

systemic lupus erythematosus

STT

scaphotrapeziotrapezoidal

TB

tuberculosis

TFC

triangular fibrocartilage

TFCC

triangular fibrocartilage complex

TMJ

temporomandibular joint

TNM

tumor-node-metastasis

VISI

volar intercalated segmental instability

WBC

white blood cells

1 Osteopenia

Osteopenia is defined as a decrease in bone density caused by reduced bone formation and/or increased bone resorption. Reduction in bone formation may result from either inadequate matrix formation (e.g., disuse osteoporosis and protein deficiency of any etiology) or inadequate matrix calcification (e. g., osteomalacia). Primary hyperparathyroidism is an example of too much resorption of both bone matrix and mineral. A combination of these causes results in the undermineralization present in the majority of osteopenic disorders. Furthermore replacement of bone matrix by benign or malignant bone proliferation (e.g. thalassemia, multiple myeloma and leukemia) or bone marrow disease (e.g. metastases, infections and storage diseases) may also result in osteopenia.

Approximately 30% of the bone mineral must be lost before a difference in the bone density can be detected by conventional radiography. More sensitive techniques useful for earlier detection and quantification of osteopenia include axial computed tomography and photon or x-ray absorptiometry. It should also be borne in mind that the normal bone density changes with age, increasing from infancy to age 35−40 and then progressively decreasing at the rate of 8% per decade in women and 3% in men.

The radiographic findings of osteopenia are loss of bone density and cortical thinning. Osteopenia may either be generalized or localized, and its differential diagnosis is discussed separately in Tables 1.1 and 1.2.

In osteoporosis, a combination of loss of bone density and cortical thinning may result in an apparent increase in density of the cortex and vertebral endplates, that appear as thin, sharp lines (Figs. 1.1 and 1.2). Bone resorption occurs preferentially in the transverse trabeculae, while the trabeculae along stress lines are accentuated. Resorption of all trabeculae in a vertebral body produces the “empty box” sign. As a result of compression fractures the vertebral body may depict a depressed endplate or become wedge-shaped, biconcave (fish vertebra) or uniformly compressed (pancake vertebral body). Cartilaginous (Schmorl's) nodes are caused by displacement of a portion of the intervertebral disc into the vertebral body. With the exception of osteogenesis imperfecta, bones do not bend in osteoporosis. A predisposition towards fractures, however, exists in the brittle bones, especially in the vertebral bodies, ribs, hips and wrists. Fracture healing is delayed and the callus formation poor. Abundant callus formation in osteopenic bones may occur, however, with exogenous (iatrogenic) or endogenous (Cushing's syndrome) hypercortisolism and osteogenesis imperfecta. In osteoporosis, serum calcium, phosphorus and alkaline phosphatase are normal.

In osteomalacia, a nonspecific loss of bone density is often the only radiographic sign. Blurring of both cortical margins and trabeculae results in a “ground glass” appearance of the involved bone and is more characteristic. This is often most obvious in the vertebral bodies. In the skull, a blurred mottled appearance similar to hyperparathyroidism is characteristic. Bones are softened and have a tendency to bend resulting in deformities commonly found in the thorax, vertebral column, pelvis and extremities. Pseudofractures (Looser's zones or Milkman's syndrome) occur frequently and represent infractions with incomplete healing. They are found in the scapula (lateral margin), ribs, clavicle, ischial and pubic rami, femur (especially medial aspect of the neck), and other long bones. Characteristic laboratory findings in osteomalacia include a slightly low to normal serum calcium, a low serum phosphorus and an elevated alkaline phosphatase.

Fig. 1.1 Osteopenia. aOsteoporosis: Deossified, biconcave vertebral bodies (fish vertebrae) with thin but dense-appearing end-plates and prominent vertical trabeculae. The superior endplates typically are affected more severely. bOsteomalacia: Uniform deossification with loss of trabecular detail (“ground-glass appearance”) and compression fractures. Fish vertebrae tend to be smoother than in osteoporosis and involve superior and inferior endplates with equal severity. cHyperparathyroidism: A “rugger jersey spine” is usually only found in secondary hyperparathyroidism (renal osteodystrophy), whereas primary hyperparathyroidism depicts a bony texture similar to osteomalacia.

Fig. 1.2 Osteoporosis (a), osteomalacia (b) and hyperparathyroidism (c and d). Osteoporosis (a): Thin sharply defined end-plates with accentuation of the vertical trabeculae are seen. Osteomalacia (b): Uniformly biconcave vertebral bodies with poorly defined endplates and blurred trabeculae are seen. Primary hyperparathyroidism (c): Thin poorly defined endplates with blurring of the trabecular pattern in the vertebral bodies are seen. Secondary hyperparathyroidism (d): Blurring of the trabecular pattern in the vertebral bodies is associated with thickening and sclerosis of the superior and inferior endplates (“rugger jersey spine”).

Bony lesions are found in less than half of the patients with hyperparathyroidism. Subperiosteal resorption along the radial margin of the phalanges is virtually pathognomonic. These erosions occur most often in the proximal and middle phalanges of the index and middle finger (Fig. 1.3). Absorption of the terminal tufts and cortical striations (“tunneling of the cortex”) are commonly associated with this condition. Endosteal resorption occurs in long bones. Resorption may also be evident in the acromial ends of the clavicles, the sacroiliac joints, the symphysis, in the calcaneus at the insertion of the plantar fascia and in the ribs (usually in their upper borders). The bone is softened resulting in secondary deformities such as basilar impression in the skull and kyphoscoliosis. Cyst-like lesions and so-called brown tumors occur in tubular and flat bones. While brown tumors heal after removal of the parathyroid adenoma and may eventually even become sclerotic, cysts remain unchanged after treatment. Granular deossification of the skull results in a “salt and pepper” appearance. Resorption of the lamina dura around the teeth is commonly present. Soft tissue calcifications (especially arterial and para-articular), joint cartilage calcifications (especially menisci and the triangular fibrocartilage in the wrist), nephrocalcinosis, and nephroureterolithiasis are common features of hyper-parathyroidism. Pancreatitis, peptic ulcer disease and gallstones may also be associated. Classic laboratory findings in primary hyperparathyroidism include a high serum calcium, a low serum phosphorus, and an elevated alkaline phosphatase in the presence of bone disease.

Fig. 1.3 Hyperparathyroidism of the hand. Subperiosteal resorption and cortical striations, usually best seen on the radial margins of proximal and middle phalanges of second and third finger. A magnified view of these findings is demonstrated in insert a, whereas insert b shows a normal cortex for comparison. Additional findings include resorption of the tufts, periarticular soft-tissue calcifications, brown tumors (third metacarpal and capitatum), and joint cartilage calcification (often in the triangular fibrocartilage between ulna and corresponding part of the proximal carpal row).

An increased bone density is often associated with secondary hyperparathyroidism (renal osteodystrophy). In these cases thickening of the superior and inferior endplates of the vertebral bodies can result in a “rugger jersey spine”.

The skeletal changes in different forms of hyperparathyroidism are identical, although brown tumors are more common in primary hyperparathyroidism, whereas osteosclerosis and extensive soft-tissue calcifications are more often found in secondary hyperparathyroidism.

Table 1.1 Differential Diagnosis of Generalized Osteopenia

Etiology

Comments

Osteoporosis

Laboratory findings: serum calcium, phosphorus and alkaline phosphatase all normal.

Senile or postmenopausal

Most common form of osteoporosis. Females affected more often and more severely than males. Compression fractures typically spare the less weight-bearing cervical and upper thoracic spine.

Disuse atrophy

Prolonged immobilization from any cause (e.g., neuromuscular disorders, cast).

Protein deficiency (e.g., malnutrition, nephrosis) (Fig. 1.4)

Pure dietary protein deficiency is rare. In underdeveloped countries, extensive osteopenia is associated with kwashiorkor, a marasmic protein-calorie malnutrition affecting mostly children. Protein deficiency secondary to malabsorption is more common (see under osteomalacia). Abnormal protein metabolism is the underlying cause of osteoporosis in scurvy (vitamin C deficiency) and different endocrinologic disorders.

Juvenile (idiopathic)

Between ages 8 and 14, characterized by abrupt onset of bone pain. Rare, self-limiting disorder with commonly spontaneous healing.

Osteogenesis imperfecta (Fig. 1.5)

Osteogenesis imperfecta congenita (fractures present at birth) and tarda (fractures absent at birth). Deformities resulting from recurrent fractures in later life and bone bending characteristic. Both disorders inherited.

Homocystinuria

Inherited disorder that presents radiographically as combination of osteoporosis, Marfan-like changes (e.g., arachnodactyly), and metaphyseal and epiphyseal widening.

Anemia (Fig. 1.6)

Bone marrow hyperplasia causes widening of the medullary space, cortical thinning, and trabecular resorption by pressure atrophy. Occurs in severe iron deficiency and sickle cell anemia, but is more pronounced in thalassemia, where a generalized cystic appearance, particularly of the flat bones, is characteristic.

Bone marrow infiltration (e.g. multiple myeloma, carcinomatosis) (Fig. 1.7)

Deossification is caused by diffuse infiltration and proliferation of tumor cells in the bone marrow resulting in endosteal erosions, cortical thinning and trabecular resorption by both pressure atrophy and destruction. While osteopenia might be the only radiologic manifestation in multiple myeloma and diffuse skeletal bony metastases, patchy osteolytic areas are often present in these conditions. Bone marrow infiltration associated with cortical thinning and trabecular resorption can also be found in reticuloses (e.g. Gaucher's and Nieman-Pick disease), histiocytoses and hyperlipoproteinemias. In children, leukemia frequently causes osteopenia.

Connective tissue disease (especially rheumatoid arthritis)

Other more characteristic radiographic findings are often associated with the disease suggesting the correct diagnosis (see Chapter 6).

Endocrine disorders

Hypogonadism: osteoporosis associated with delayed epiphyseal fusion (e.g., Turner's syndrome, eunuchoidism). Cushing's syndrome: chronic excess of glucocorticoids. Addison's disease: insufficiency of the adrenal cortex. Diabetes mellitus: osteopenia present in about 50% of patients.

Hyperthyroidism: often associated with cortical striations best seen in metacarpal bones. See also under hyperparathyroidism in this table.

Drug-induced (e.g., steroids, heparin) (Fig. 1.8)

Steroids: large dosages over several months. Heparin: 15,000 to 30,000 units for six months or longer.

Osteomalacia (Fig. 1.9)

Laboratory findings in osteomalacia: serum calcium slightly low to normal; serum phosphorus low; alkaline phosphatase elevated.

Deficient absorption of calcium and/or phosphorus;

1. vitamin D deficiency

Dietary causes, or lack of sunshine

Adult: osteomalacia. Loss of bone density with blurring of both cortical margins and trabeculae characteristic. Bowing deformities and pseudofractures occur frequently. Children: rickets (Fig. 1.10). Most commonly found in premature infants. Develops most commonly between 6 and 12 months of age. Radiographic features include: indistinct, frayed and concave metaphyses (“cupping”) with perpendicular trabeculae extending towards the epiphyseal areas. Delayed appearance of epiphyseal ossification centers with blurred margins (DD: Scurvy: sharply outlined epiphyses). Bulky growth plates in long bones result in swelling around the joints and a “rachitic rosary” at the costochondral junctions of the middle ribs.

2. Malabsorption

Diseases of the gastrointestinal tract, hepatobiliary system and pancreas associated with malabsorption are the most common cause of Vitamin D deficiency in developed countries. Rickets and osteomalacia is commonly associated with sprue, celiac disease, Crohn's disease, scleroderma, small bowel fistulas, blind loop syndromes, small intestinal bypass surgery, and gastric or small bowel resection.

3. Dietary calcium deficiency

Extremely rare.

Defects in renal tubular or intestinal calcium phosphate transport system:

1. Vitamin D-resistant rickets (x-linked hypophosphatemia) and pseudo-vitamin D deficiency rickets (Figs. 1.11 and 1.12)

Proximal tubular resorption of phosphorus decreased. Inherited (X-linked dominant and autosomal recessive) disorders with similar clinical features (short stature, multiple fractures, varus or valgus deformities of the knees, bowing deformities of the long bones in the lower extremities and muscular weakness), but only the latter condition is commonly associated with convulsions. Enthesopathy in the spine may resemble ankylosing spondylitis but without erosions in the sacroiliac joints.

2. Renal tubular acidosis (Fig. 1.13)

Metabolic acidosis attributed to renal loss of alkali. Pathogenesis of osteomalacia in this condition is unclear. Commonly associated with nephrocalcinosis and nephrourolithiasis.

3. Fanconi's syndrome (De Toni-Debré-Fanconi syndrome)

Idiopathic or acquired disorder characterized by hypophosphatemia, glucosuria and aminoaciduria. The idiopathic form is often associated with cystinosis (widespread tissue deposition of cystine crystals). The acquired form may be secondary to Wilson's disease (rare familial disorder with impaired hepatic excretion of copper and characteristic pigmentation of the cornea [Kayser-Fleischer ring], multiple myeloma and lead or cadmium poisoning.

Chronic anticonvulsant drug therapy

Anticonvulsants (e.g. Phenytoin) and many tranquilizers induce hepatic enzymes that accelerate degradation of biologically active vitamin D metabolites.

Fibrogenesis imperfecta ossium and axial osteomalacia

Fibrogenesis imperfecta ossium (axial and appendicular bone involved) and axial osteomalacia (only axial skeleton involved) are rare disorders found in middle-aged males. Loss of bone density with a few coarse trabeculae may produce a “fishnet appearance.” Occasionally, the bone density may increase.

Hypophosphatasia (Fig. 1.14)

Autosomal recessive disorder with a wide spectrum of clinical severity. Generalized deficient bony mineralization is found radiographically. The most severe skeletal involvement is observed in neonates, in whom the disease is often fatal. In childhood the disorder resembles rickets, but associated irregular lucent extensions into the metaphyses representing uncalcified bone matrix are characteristic. The adult form is characterized by radiolucent bones, pseudofractures, and fractures occurring after minor trauma that show delayed healing with minimal callus formation. Biochemical hallmark; low alkaline phosphatase.

Hyperparathyroidism (Figs. 1.15 and 1.16)

Laboratory findings of primary hyperparathyroidism: serum calcium high; serum phosphorus low; alkaline phosphatase elevated in the presence of bone disease.

Primary hyperparathyroidism

Found with parathyroid adenoma, primary chief cell or clear cell hyperplasia of all parathyroid glands, and parathyroid carcinoma.

Secondary hyperparathyroidism

Compensatory mechanism in any state of true hypocalcemia. Usually due to chronic renal failure, but may also be caused by hypovitaminosis D and malabsorption of calcium. In chronic renal disease, the skeletal changes are usually a combination of hyperparathyroidism, osteomalacia and osteosclerosis. This complex is best referred to as “renal osteodystrophy.”

Tertiary hyperparathyroidism

Development of an autonomous parathyroid adenoma in chronically overstimulated hyperplastic parathyroid glands (e.g., following renal transplantation).

Fig. 1.4 a, b Scurvy. Characteristic findings include: (1) Osteopenia with markedly thinned cortex, (2) thin, dense, ring-like calcification around the epiphysis (Wimberger's line), (3) dense, linear calcifications in the distal metaphysis (“white line of Frankel”), (4) a small bone spur immediately adjoining the “white line of Frankel” (Pelkan's spur), (5) a radiolucent band proximal to the “white line of Frankel” (Trummerfeld zone), and (6) subperiosteal hemorrhage (calcifies only after therapy is instituted). Epiphyseal separation and/or fragmentation in the region of the metaphysis may also be associated.

Fig. 1.5a, b Osteogenesis imperfecta. Diffuse osteopenia with bowing deformities of the narrowed (overconstricted) tibia and fibula shafts with flaring of the metaphyses is seen in anteroposterior (a) and lateral (b) projections.

Fig. 1.6 Thalassemia major. Chest (a) and pelvis (b). Generalized, cystic-appearing osteopenia caused by red bone marrow hyperplasia, with main involvement of the central or flat bones characteristic. Note also the bulbous widening of the anterior ends of the ribs.

Fig. 1.7 Multiple myeloma presenting as generalized osteopenia in the spine. In this case, however, extensive destruction of L1 and the destroyed left pedicle of L5 suggest the malignant process.

Fig. 1.8 Steroid-induced osteoporosis. Osteoporosis with thickening and sclerosis of the compressed end-plates is characteristic of exogenous or endogenous hypercortisolism.

Fig. 1.9 Osteomalacia. Marked demineralization with blurring of the inner cortical margins and loss of trabeculations are characteristic. Several pseudofractures are seen, presenting as sclerotic transverse lines in the tibia.

Fig. 1.10 Rickets. Characteristic changes include: (1) osteopenia, (2) poorly calcified and defined epiphyses, (3) widening of the epiphyseal cartilage plate, (4) widening, cupping, and fraying of the metaphyses, (5) periosteal reactions, and (6) bowing deformities. Greenstick fractures are also commonly associated, but not present in this case.

Fig. 1.11 Vitamin D-resistent rickets (x-linked hypophosphatemia). Osteopenia with multiple fractures/pseudofractures and anterior bowing deformity of the tibia is seen.

Fig. 1.12 Vitamin D-resistent rickets (x-lilnked hypophosphatemia). Mild osteopnia with bowing deformity and pseudofracture in the distal femur and genu varum is seen.

Fig. 1.13 Renal tubular acidosis. Increased bone density secondary to renal osteodystrophy is seen. Note also the extensive bilateral nephrocalcinosis.

Fig. 1.14 Hypophosphatasia. Osteopenia and a radiolucent lesion (arrows) extending from the growth plate into the distal femur metaphysis representing uncalcified bone matrix are seen.

Fig. 1.15 Hyperparathyroidism. Subperiosteal resorption best seen along the radial margin of the proximal phalanges of both index fingers. Brown tumors involving the distal phalanx of the left index finger and the entire right third metacarpal bone. Resorption of the tufts, especially in the thumbs. The cortex in the metacarpals and phalanges depicts fine striations.

Fig. 1.16 Hyperparathyroidism. Subperiosteal resorptions seen along the radial margins of the proximal and middle phalanges of the second finger and the middle phalanx of the third finger are virtually diagnostic. Cortical striations are also evident.

Table 1.2 Differential Diagnosis of Localized Osteopenia

Etiology

Comments

Disuse atrophy (local immobilization):

1. fracture (more pronounced distal to the fracture site)

2. cast

3. neural paralysis

4. muscular paralysis

Besides identical radiographic features as in generalized osteopenia, the localized form may also have a patchy appearance due to spotty cortical thinning (e. g., reflex sympathetic dystrophy).

Reflex sympathetic dystrophy (RSD, Sudeck's atrophy) (Fig. 1.17)

Rapid development of often patchy osteoporosis associated with painful soft-tissue swelling following trivial trauma. Cerebrovascular disorders, cervical spondylosis, discal herniation, postinfectious states, calcific tendinitis, vasculitis, and neoplasm are other implicated conditions. Probably of neurovascular origin.

Regional transitory osteoporosis

A painful self-limited osteoporosis in middle-aged or elderly patients. Most often found in the hip (“transitory demineralization of the femoral head”), but may also involve any other major joint. Associated with disability lasting 2 to 4 months.

Shoulder-hand syndrome (Fig. 1.18)

Pain and stiffness in the shoulder combined with pain, swelling and vasomotor phenomena in the hand following an acute illness (e.g. myocardial infarction, in which condition it is usually located on the left side). Radiographically, it resembles reflex sympathetic dystrophy.

Burns and frostbites

Radiographic findings consist of osteoporosis, bone resorption, osteonecrosis, and dystrophic soft tissue calcifications (burns).

Inflammatory:

1. rheumatoid arthritis

2. osteomyelitis

3. tuberculosis

Localized osteoporosis is usually the first, although nonspecific, radiographic manifestation of any inflammatory disease.

Bone infarct and hemorrhage

In their early stages, both bone infarcts and hemorrhages produce localized demineralization. With healing, lesions become calcified and eventually osteosclerotic.

Radiation osteonecrosis (Fig. 1.19)

Radiation changes are dose-related, with a threshold level of 30 Gy and cell death occurring at 50 Gy. Radiographic changes occur one year after radiotherapy at the earliest. They are initially often predominantly lytic, and progress with time to a mixed lytic and sclerotic stage.

Tumor (Fig. 1.20)

Osteolytic metastases and multiple myeloma must primarily be considered. Primary bone tumors (benign or malignant) may present as localized deossification, but only rarely.

Paget's disease (lytic phase) (Fig.1.21)

Skull: osteoporosis circumscripta. Long bones: usually a well-defined and V- or wedge-shaped area of deossification originating in the subchondral bone of an epiphysis.

Fibrous dysplasia (Fig. 1.22)

Both purely lytic lesions and a homogeneous, “ground glass” appearance occur, besides predominantly sclerotic manifestations. Cortical thinning and bony expansion is commonly associated with lytic lesions in tubular bones.

Fig. 1.17 Reflex sympathetic dystrophy. Patchy demineralization most severe near the joints is quite characteristic.

Fig. 1.18a, b Shoulder-hand syndrome. Deossification limited to the left shoulder (a) and hand (b) several weeks following myocardial infarction is characteristic.

Fig. 1.19 Radiation osteonecrosis. Deossification of the distal end of the clavicle with endosteal bone resorption is seen 4 years after irradiation for breast carcinoma.

Fig. 1.20 Multiple myeloma. Demineralization is most pronounced near the joints, as in reflex sympathetic dystrophy in Fig. 1.17.

Fig. 1.21 a, b Paget's disease. The lytic phase in two different patients. Relatively well-defined V-or flame-shaped areas of deossification containing strands of increased bony densities in a slightly expanded shaft are characteristic (a: proximal tibia, b: distal tibia and fibula).

Fig. 1.22 Fibrous dysplasia. Widening of the humerus, with a “ground glass” appearance and a few scattered patchy sclerotic areas, is evident.

2 Osteosclerosis

Osteosclerosis is defined as an increase in bone density caused by increased activity of osteoblasts or by osteogenic or chondrogenic tumor cells forming bone-like tissue. Calcification of tissue other than osteoid within bone is usually dystrophic in nature and may also increase the bone density radiographically.

Ossifications within the medullary cavity commonly present as homogeneous, fluffy, cotton-like or cloud-like densities. They most often are caused by bone islands or osteoblastic metastases (Figs. 2.1 and 2.2). Calcifications within the medullary cavity typically present as punctate, annular, comma-shaped or shell-like densities and are commonly associated with chondroid matrix tumors and bone infarcts (Figs. 2.3 and 2.4).

The increase in bone density may be scattered or diffuse. This distinction appears useful in the differential diagnosis of osteoblastic reactions, since certain diseases may exclusively present as scattered (solitary or multiple) sclerosis. Accordingly, the differential diagnosis of these entities will be discussed separately in Tables 2.1 and 2.2. Table 2.3 lists sites and commonly used eponyms for idiopathic avascular necrosis.

Fig. 2.1 Bone island. A sclerotic focus is seen in the intertrochanteric area. The lesion depicts both tiny radiating bone spicules in its periphery and a central radiolucency, both radiographic features that help to differentiate it from an osteoblastic metastasis.

Fig. 2.2 Osteoblastic metastasis (breast carcinoma). An osteoblastic lesion is seen in the intertrochanteric area.

Fig. 2.3 Enchondroma. An oblong lesion consisting of multiple irregular, often punctate calcifications is seen in the proximal tibia shaft.

Fig. 2.4 Bone infarct. An oblong radiodense lesion with shell-like calcifications is seen in the distal femur shaft.

Table 2.1 Solitary or Multiple Scattered Osteosclerotic Lesions

Disease

Radiographic Findings

Comments

Bone island (enostosis) (Fig. 2.5)

Well-circumscribed isolated area of increased density rarely exceeding 1 cm in diameter. A very slow growth in size is occasionally observed. Margins demonstrate characteristically tiny spiculations or a “brush” border. A central radiolucency is occasionally observed. Occur at any location but pelvis and upper femora appear to be most common locations.

Radionuclide bone imaging is normal. (DD: Osteoblastic metastases are invariably associated with a markedly increased radionuclide uptake.)

A large, very dense and structureless bone island within the medullary cavity is often called enostoma (Fig. 2.6). Without proper clinical history such a lesion is often indistinguishable from a surgically excised and methylmethacrylate cemented bone lesion (Fig. 2.7).

Osteopoikilosis (Fig. 2.8)

Multiple round or ovoid bone densities ranging in size from 2 mm to 2 cm. May demonstrate a radiolucent center. Can be found in all bones, but skull, mandible, ribs, sternum, and vertebrae are only rarely involved. In long bones they are characteristically located in metaphyses and epiphyses, whereas in the scapula and pelvis they are typically found around the glenoid fossa and acetabulum, respectively.

Rare familial disorder not associated with clinical symptoms and therefore incidentally discovered at any age. No increased radionuclide uptake is found in bone scans.

Osteopathia striata (Fig. 2.9)

Dense longitudinal striations that involve the metaphyses and may extend into the epiphyses and diaphyses. In the ilium, the linear densities radiate from the acetabulum. Vertebral bodies and skull may also be involved.

Rare and usually asymptomatic bone disorder. Occasionally associated with focal dermal hypoplasia (Goltz's syndrome)

Chondrodysplasia punctata (congenital stippled epiphyses) (Fig. 2.10)

Multiple punctate calcifications occurring in the epiphyses before the normal time of appearance of the epiphyseal ossification centers. DD: Zellweger's cerebrohepatorenal syndrome, where the stippling is limited to the patella.

Rare genetically heterogeneous epiphyseal dysplasia associated with a broad spectrum of clinical symptoms. Affected bones may be shortened, or the disorder may regress and leave no deformities. The epiphyseal calcifications may disappear by the age of 3, or may gradually increase in size and coalesce to form a normal-appearing single ossification center.

Multiple epiphyseal dysplasia (Fairbank's disease)

Irregular mottled calcifications of the epiphyses diagnosed in children and adolescents. Sequelae in the adult consist of epiphyseal irregularities, degenerative joint changes, and rarely, asymmetrical shortening of tubular bones.

Can be considered to be the tarda form of chondrodysplasia punctata.

Cretinism with delayed appearance of stippled and fragmented epiphyseal ossification centers and sclerotic metaphyseal bands must be differentiated.

Melorheostosis (Fig. 2.11)

Presents in early stage as linear hyperostosis beginning at one end of a tubular bone, progresses with time towards the diaphyses, and results finally in cortical thickening involving either one side or the entire cortex. The lesion may simulate wax flowing down the side of a candle. Osteoma-like protrusions and soft tissue ossifications may be associated.

Often limited to a single limb, in which one or more bones may be affected. At an advanced stage it is part of the differential diagnosis of diffuse osteosclerosis and will be discussed in Table 2.2.

Osteoma (Fig. 2.12)

Protruding mass lesion composed of abnormally dense bone with structureless appearance. It rarely exceeds 2 cm in diameter, and is usually confined to bone that is produced by the periosteal membrane. It arises from the outer or inner table of the skull, the paranasal sinuses (especially frontal and ethmoid), from the mandible, maxilla, and rarely from the tubular bones of the extremities.

Benign hamartomatous lesion consisting exclusively of osseous tissue.

Gardner's syndrome: Multiple osteomas associated with soft tissue tumors and pre-malignant polyposis, mainly of the colon.

Benign and malignant bone tumors (Figs. 2.13, 2.14 and 2.15)

Predominantly sclerotic lesions, either as a solitary focus (enchondroma, osteochondroma, chondrosarcoma, osteoid osteoma, osteoblastoma, osteosarcoma, and Ewing's sarcoma) or as multiple foci (enchondromatosis or Ollier's disease, hereditary multiple exostoses or diaphyseal aclasis, and osteosarcomatosis).

Differential diagnosis of bone tumors is discussed in detail in Chapter 5.

Osteoblastic metastases (Fig. 2.16)

Poorly defined areas of increased density with indistinct or lost trabecular structure. With increase in size, adjacent metastases may coalesce, resulting finally in most diffuse sclerosis. With the exception of renal and most thyroid carcinomas which produce invariably lytic and often expansile metastases, osteoblastic metastases may originate from virtually every carcinoma, but carcinoma of the prostate and breast are the most common sources. Other primary tumors include osteosarcomas, carcinoids, and carcinomas originating in the lung, nasopharynx, gastrointestinal tract and urinary bladder. Of the lymphomas, Hodgkin's disease and histiocytic lymphoma (reticulum cell sarcoma) are most likely to produce osteoblastic bone lesions.

In children, leukemia, neuroblastoma, and Ewing's sarcoma metastases must be considered, although these lesions are more commonly lytic before treatment is instituted.

Multiple myeloma

Focal sclerotic lesions are a rare initial manifestation.

Characteristic lytic lesions may become sclerotic with proper therapy.

Plasma cell granuloma (Fig, 2.17)

Solitary or scattered osteoblastic foci that are only slowly growing.

Consists histologically of a dense infiltrate of normal plasma cells. In contrast to multiple myeloma and plasmacytoma, all laboratory findings are normal. Nowadays considered to be a variant of chronic recurrent multifocal osteomyelitis (CRMO) or SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis), respectively

POEMS syndrome

Solitary or multiple osteosclerotic lesions and fluffy spiculated hyperostotic areas preferentially at sites of ligamentous attachment in axial and para-axial locations.

POEMS is the acronym for polyneuropathy, or-ganomegaly, endocrinopathy, M protein, and skin changes.

Chronic or healed osteomyelitis (Fig. 2.18)

May present as localized, thickened sclerotic bone usually containing radiolucent areas.

Bacterial, tuberculous, and fungal organisms may all cause a chronic sclerosing-type osteomyelitis. Sclerosing osteomyelitis of Garre is a low-grade chronic infection not associated with bone destruction or sequestration.

Brodie's abscess (Fig. 2.19)

Central lucency surrounded by a slight to extensive reactive sclerosis. Located typically in the metaphysis and, less commonly in the epiphysis or diaphysis of tubular bones. Cortical thickening, periosteal new bone and sequestrum formation may be found with Brodie's abscess, but are not typical.

Chronic, often painful lesion.

Tropical ulcer

Often expansile lesion involving preferentially the lower half of the tibia. Associated with periostitis, resulting in localized fusiform periosteal and cortical thickening or even broad-based excrescences resembling osteomas.

In patients of all ages in Central and East Africa.

Callus formation (Fig. 2.20)

Healed fractures result in a localized increase in bone density.

Commonly in ribs or metatarsals following a fatigue fracture.

Stress fracture (Fig. 2.21)

Findings dependent on both location and time. A fracture line (cortical or complete) is not always evident. In the shaft of tubular bones, localized cortical thickening and periosteal reaction are characteristic. At the end of tubular bones (e.g. femoral neck, tibia plateau) and in cancellous bone, a band-like focal sclerosis without appreciable periosteal reaction is usually found.

Presents clinically with activity-related pain that is relieved by rest. Radionuclide examination and magnetic resonance imaging are both much more sensitive for early detection and diagnosis. A stress fracture occurring in normal bone under abnormal (increased) stress is referred to as a fatigue fracture, whereas a stress fracture occurring in abnormal (osteopenic) bone with normal stress is referred to as an insufficiency fracture.

Healed bone lesion (Fig. 2.22)

Spontaneously or under appropriate treatment, healed lytic lesion may become sclerotic.

Benign bone lesions such as fibrous cortical defects and nonossifying fibromas may spontaneously regress and persist as sclerotic foci. Lytic metastases (e.g., from bronchogenic carcinoma, breast carcinoma, lymphoma) and multiple myeloma manifestations may respond to local irradiation, chemotherapy, and/or hormone therapy by becoming osteosclerotic. Brown tumors in primary hyperparathyroidism become sclerotic after removal of the parathyroid adenoma.

Bone infarcts (old) (Figs. 2.23 and 2.24)

Most often found in the proximal or distal ends of long tubular bones. Healed infarcts present as irregularly calcified areas in the medullary cavity, demarcated from the normal bone by a dense serpiginous contour or irregular streaks. The calcifications may eventually progress to ossification.

Infarcts are often associated with other diseases such as occlusive vascular disease, sickle cell anemia, pancreatitis, connective tissue disease, caisson disease, Gaucher's disease, and radiation therapy.

A similar calcification in the medulla of long bones can occasionally be seen after removal of an intramedullary rod. Enchondromas can simulate bone infarcts (Fig. 2.25).

Radiation osteonecrosis (Fig. 2.26)

May present years after therapy as a mixture of sclerotic and lytic lesions even when no infarcts have occurred.

This condition can be differentiated from a local tumor recurrence with bone involvement by a normal or even depressed uptake on a bone scan.

Avascular (epiphyseal) necrosis (AVN) (Fig. 2.27)

Sequelae of avascular necrosis in epiphyses consist of sclerotic and cystic areas of flattened and irregular joint surfaces, which lead to early secondary degenerative changes, particularly in the weight-bearing joints. Most idiopathic avascular necroses occur during childhood and adolescence. Idiopathic avascular necroses occurring in adulthood are found in the medial femur condyle (Ahlbäck's disease, also reffered to as spontaneous osteonecrosis about the knee or SONC) and in the lunate (Kienböck's disease). Ahlbäck's disease typically occurs in the elderly with female predominance and occasionally affect the lateral femoral ar the tibial condyles. New evidence suggest it represents a stress (insufficiency) fracture rather than a spontaneous osteonecrosis. Kienböck's disease is usually found in young adults. In an advanced stage, the lunate shows increased bone density, fragmentation, and compression.

May be found in any disorder associated with medullary bone infarcts. Avascular necrosis is caused by interruption of the blood supply to the epiphyses with subsequent death of the hematopoetic cells in 6–12 hours, osteocytes in 12–48 hours, and lipocytes in 2–5 days. The etiology may be traumatic (e. g., femoral neck fracture), thromboembolic (e. g., sickle cell disease), vasculitic (e. g., systemic lupus erythematosus), stereoidal, marrow-infiltrative (e. g., Gaucher's disease) or idiopathic (e.g., Legg-Calvé-Perthes disease). An idiopathic genesis of this abnormality is commonly associated with an eponym (see Table 2.3).

Paget's disease (Fig. 2.28)

Can cause uniform areas of increased bone density in the sclerotic phase. In the reparative (mixed lytic and sclerotic) stage, the disease is characteristically associated with cortical thickening resulting in enlargement of the affected bone. Any bone can be affected; “cotton wool” appearance of the skull and “ivory vertebral body” are representative examples of the sclerotic phase of the disease.

Purely sclerotic phase is less common than the combined destructive and reparative stage virtually pathognomonic for the disease.

Fibrous dysplasia

Besides having a cyst-like or “ground glass” appearance, it can also present as purely sclerotic lesions. Manifestations are usually associated with bone expansion, particularly in tubular bones. With more extensive involvement, bone deformities almost invariably occur.

Occurs in monostotic and polyostotic forms. An ossifying fibroma of the skull, face and mandible cannot be histologically differentiated from fibrous dysplasia, and can be considered radiographically as a localized manifestation of this disease. Ossifying fibromas occuring in long bones, especially in the tibia and to a lesser extend fibula are referred to as osteofibrous dysplasia (Fig. 2.29)

Mastocytosis (Fig. 2.30)

Can present with focal or diffuse bone involvement. Focal form is characterized by scattered, well-defined sclerotic foci often alternating with areas of bone rarefaction. Skull, spine, ribs, pelvis, humerus, and femur are preferred sites of involvement.

Majority of patients develop skin lesions containing mast cells during the first year of life. Hepatosplenomegaly, lymphadenopathy, and pancytopenia may be associated.

Tuberous sclerosis (Fig. 2.31)

Often presenting with scattered intracerebral calcifications, renal hamartomas, and bone lesions. Characteristic skeletal changes are patches of osteosclerosis ranging from a few millimeters to several centimeters in diameter. The lesions are not associated with any bone enlargement, and are most commonly found in skull, lumbar spine (especially pedicles), and pelvis, although all bones may be involved. Cyst like lesions may be seen in the hands and feet.

Rare familial disorder with defect in developing ectodermal structures. Present clinically with adenoma sebaceum of the face, with epilepsy, and with mental deficiency.

Sarcoidosis (Fig. 2.32)

Focal or generalized osteosclerosis is a rare manifestation involving spine, pelvis, skull, ribs, proximal long bones and terminal phalanges (acroosteosclerosis).

A more characteristic presentation that is found especially in the bones of the hand consists of osteopenia with a coarsened, reticulated or lace-work trabecular pattern and localized cystic (“punched-out”) lesions.

Fig. 2.5 Bone island. Well-circumscribed focus of increased density with tiny spiculations in its periphery (“brush” border) is seen in the ilium.

Fig. 2.6 Large bone island (enostoma). A large, very dense and structureless lesion is seen in the proximal humerus.

Fig. 2.7 Methylmethacrylate bone cement. Sequelae of excision with subsequent cementing of a giant cell tumor are seen in the distal femur.

Fig. 2.8 Osteopoikilosis. Multiple round to ovoid sclerotic lesions measuring a few millimeters in diameter are seen. In the tubular bones they are characteristically located in the metaphyses and epiphyses

Fig. 2.9 Osteopathia striata. Longitudinal striations involving the pelvis (a) and mainly the metaphyses of the femur and tibia (b) are seen.

Fig. 2.10 Chondrodysplasia punctata. Punctate calcifications are seen in the epiphyses. Note also the widened and irregular metaphyses

Fig. 2.11 Melorheostosis. Sclerosis of several metacarpals and phalanges caused by cortical thickening, often with involvement of only one side of a bone. The presentation of the disorder has been compared with the “flowing of wax down a burning candle.” Note also the involvement of the small osteoma-like protrusions from the proximal phalanx of the third finger (ulnar side) and the middle phalanx of the fourth finger (radial side).

Fig. 2.12 Osteoma. An abnormally dense lesion with structureless appearance is characteristic. In this case, the osteoma originated from the outer table and could easily be palpated.

Fig. 2.13 Osteosarcoma. A rather homogeneous sclerosis of the distal femur sparing only a small portion of the subchondral bone in the lateral femur condyle is seen.

Fig. 2.14 Parosteal sarcoma. This posterior cortical tumor of the distal femur diaphysis presents as an irregularly defined sclerotic lesion in this anteroposterior projection (viewed face-on). The lateral projection of this sarcoma is shown in Fig. 4.49.

Fig. 2.15 Ewing's sarcoma. A relatively poorly defined sclerotic lesion is seen in L3 involving the posterior two-thirds of the vertebral body and pedicles.

Fig. 2.16 Osteoblastic metastases from prostatic carcinoma (a) involving the spine and pelvis and from Hodgkin's disease (b) involving only the left fourth and fifth rib. The involvement of different vertebral bodies varies from barely visible, poorly defined areas of increased densities in some vertebrae to almost complete sclerosis (“ivory vertebra”) in L4.

Fig. 2.17 Plasma cell granuloma. Scattered osteoblastic lesions and a larger osteoblastic area in the left ilium adjacent to the sacroiliac joint are seen.

Fig. 2.18 Sclerosing osteomyelitis of Garré. A homogeneous sclerosis of the proximal spindle-shaped tibia shaft is seen.

Fig. 2.19 Brodie's abscess. Radiolucent lesion with surrounding reactive sclerosis in the distal tibia metaphysis is characteristic

Fig. 2.20 Healed fracture. Irregular widening of the shaft, cortical thickening and sclerosis is seen in this healed comminuted fracture of the proximal femur.

Fig. 2.21 Insufficiency fracture. A poorly defined osteosclerotic zone is seen in the lateral aspect of the proximal tibia.

Fig. 2.22 Brown tumor in primary hyperparathyroidism, a before and b five years after removal of a parathyroid adenoma, Healing of the brown tumor resulted in a persistent sclerotic focus.

Fig. 2.23 a, b Bone infarcts. Irregular peripheral rim calcifications are seen in the distal femur (a) and more extensive in both the distal femur and proximal tibia (b) in these patients with sickle cell anemia.

Fig. 2.24 a, b Bone infarcts. In an attempt to heal the originally calcified infarct becomes ossified from its periphery towards the center and eventually presents as an irregular sclerotic lesion as seen in the proximal femur shaft in a and about the knee in b.

Fig. 2.25 Enchondroma. An irregular calcification is seen that is most dense in its center.

Fig. 2.26 Radiation osteonecrosis. Mixed osteolytic and osteoblastic lesions are seen in both pubic bones with several pathologic fractures 7 years after irradiation for bladder carcinoma.

Fig. 2.27 Avascular necrosis of the lunate (Kienbock's disease). Increased sclerosis of the lunate, which is compressed and shows early fragmentation. A shortening of the ulna (negative ulnar variance) as present in this case has been implicated as predisposing to Kienbock's disease through increased pressure on the lunate from the medial corner of the distal radius.

Fig. 2.28 Paget's disease. A slightly thickened and uniformly sclerotic clavicle is seen.

Fig. 2.29 Osteo fibrous dysplasia. Anterior bowing of the sclerotic and slightly widened tibia shaft with a thickened irregular posterior cortex and several lytic lesions in the anterior cortex are seen. Similar but less severe changes are also present in the fibula.

Fig. 2.30 Mastocytosis. Multiple sclerotic foci are evident.

Fig. 2.31 Tuberous sclerosis. Irregular sclerotic areas are interspersed with small cyst-like lesions.

Fig. 2.32 Sarcoidosis. Poorly defined patchy sclerotic areas are noted throughout the spine.

Table 2.2 Generalized Diffuse Osteosclerosis

Disease

Radiographic Findings

Comments

Physiologic osteosclerosis of newborn

Cortical thickening and abundant spongiosa formation can result in considerable osteosclerosis, mainly affecting the long tubular bones.

Sclerotic changes disappear gradually during the first weeks of life and have no pathologic significance. Can be found in more than half of all premature infants.

Congenital syphilis (Fig.2.33)

Symmetrical involvement of metaphyses and diaphyses, with the epiphyseal ossification centers being spared. Metaphyseal involvement varies from transverse striping to destructive lesions originating in the corners adjacent to the cartilage plate and a frayed appearance of the metaphyseal ends similar to rickets. Particularly characteristic is a destructive lesion adjacent to the medial metaphyseal growth plate of the proximal tibia (Wimberger's sign). In the diaphyses, subperiosteal cortical thickening and periosteal reactions may be associated with focal destructive lesions.

Changes in congenital syphilis caused by a combination of luetic osteomyelitis and nonspecific trophic disturbances in enchondral bone formation. Radiographic changes may be present at birth or develop subsequently.

Rubella embryopathy (Fig. 2.34)

Predilection for distal femoral and proximal tibial metaphyses and adjacent diaphyses where irregular longitudinal lytic and sclerotic densities are found, giving a “celery-stick” appearance. Metaphyseal ends are irregular but not cupped.

Caused by maternal rubella infection in the first trimester of pregnancy. Associated clinical findings may include congenital heart disease, hepatosplenomegaly, cataracts, chorioretinitis, and thrombocytopenic purpura.

Toxoplasmosis and cytomegalic inclusion disease may result in similar bony changes.

Erythroblastosis fetalis

Transverse metaphyseal bands and diffuse sclerosis of the diaphyses may be present.

Congenital hemolytic anemia caused by Rh factor incompatibility. Clinically, severe prolonged jaundice (icterus gravis neonatorum) and generalized edema (hydrops fetalis) are associated.

Infantile cortical hyperostosis (Caffey's disease) (Fig. 2.35)

Cortical thickening, sometimes with asymmetrical distribution. Mandible clavicles, long bones (especially ulnae), ribs, skull, scapula and pelvis are involved, in that order of frequency. Tubular bones may have a spindle-shape appearance since only the diaphyses are involved. A laminated periosteal reaction is only associated in the healing phase.

Uncommon disease of unknown etiology with onset in the first 5 months. Clinically, the affected bones are associated with tender soft tissue swellings and fever. Recovery occurs over a period of a few weeks to several months. Roentgen changes regress within a year.

Ribbing's disease

Solitary or multiple, often asymmetric involvement of the diaphyses of long bones (especially femur and tibia) with sclerosis and hyperostosis.

Usually asymptomatic and often considered as forme fruste of Engelmann-Camurati disease. When a solitary bone is involved the differential diagnosis includes chronic sclerosing osteomyelitis of Garré.

Progressive diaphyseal dysplasia (Engelmann-Camurati disease) (Fig. 2.36)

Cortical thickening of the long bones beginning in the midshaft and progressing peripherally, resulting in a spindle-shape appearance with relatively abrupt transition to normal bone. Involvement of other bones with sclerosis is less common.

This autosomal dominant transmitted neuromuscular disease is usually diagnosed between 4 and 12 years of age. Characteristic clinical features include a peculiar wide-based, waddling gait, muscular weakness, and malnutrition.

Generalized cortical hyperostosis (van Buchem's disease) (Fig. 2.37)

Diffuse symmetrical sclerosis and cortical thickening, predominantly of the diaphyses of all tubular bones. Sclerosis and thickening occurs also in the vault and base of the skull, mandible, clavicles, ribs and spine (particularly affecting the spinous processes).

Rare autosomal recessive disorder occurring in adulthood with male predominance. Worth's syndrome: Autosomal dominant form, with similar but less severe radiographic findings, is often detected incidentally on radiographs obtained for unrelated reasons.

Hereditary hyperphosphatasia (Juvenile Paget's disease)

Marked cortical thickening can be found in all bones. In the long tubular bones the process involves the entire bone rather than only the diaphyses and bowing deformities occur, especially in the femora. Pseudofractures and “splitting” of the cortex may also be seen.

Rare autosomal recessive disease developing usually in the second or third year of life with striking, predilection for those of Puerto Rican descent. Radiographic features resemble Paget's disease. Alkaline phosphatase is elevated. Pseudoxanthoma elasticum may be associated.

Craniometaphyseal dysplasia

Osteosclerosis of the diaphyses of the tubular bones is only found in infancy, and is subsequently replaced by widened diaphyses with cortical thinning and metaphyseal expansion (Erlenmeyer flask deformity). Sclerosis of the skull (calvarium and base) occurs. Lack of aeration of the paranasal sinuses and mastoids is present. The mandible can be markedly thickened and sclerotic, with defective dentition.

Rare autosomal dominant or recessive disorders characterized by failure of normal tubulation of bone and skull abnormalities. Clinically, hypertelorism and a broad flat nose are characteristic, and cranial nerve deficits (progressive hearing and vision loss and facial paralysis) occur.

In craniodiaphyseal dysplasia (autosomal recessive) massive and progressive hyperostosis of the skull and facial bones are associated with cortical thickening and lack of normal modeling of the long and short tubular bones (Fig. 2.37A).

Hypoparathyroidism

Osteosclerosis, particularly of the axial skeleton, is the most common bony abnormality, but may be subtle and defy detection. Transverse sclerotic bands in the metaphyses of the long bones, increased density of the iliac crest, and marginal sclerosis of vertebral bodies can also be found. Ossification of muscle insertion and ligaments and subcutaneous calcifications occur. Enthesopathy in the spine resembles diffuse idiopathic skeletal hyperostosis (DISH). In the skull calvarial thickening, basal ganglion calcification and defective dentition are characteristic.

Hypocalcemia induces neuromuscular excitability, resulting eventually in tetany in both primary and the more common secondary hypoparathyroidism. The latter is most often caused by accidental removal of the parathyroid glands during thyroid surgery.

Pseudohypoparathyroidism differs from the primary form by the presence of short metacarpal and metatarsal bones and the lack of response to parathyroid hormone substitution therapy. Pseudopseudohypoparathyroidism has similar radiographic features, but no blood chemical changes.

Osteopetrosis (marble bones, Albers-Schönberg disease) (Fig. 2.38)

Symmetrical increase in bone density ranging from minimal to extreme may be found. All bones may be involved with no predilection for a specific location within one bone. Tubular bones lack modeling, often causing flaring of the ends (Erlenmeyer flask deformity). Longitudinal and transverse striations as well as “bone-within-bone” appearance occur.

Rare hereditary bone disorder with usually normal serum calcium, phosphorus, and alkaline phosphatase levels. At least four different types are differentiated, one of which is associated with tubular acidosis.

Pyknodysostosis

Diffuse Osteosclerosis occurs but differs from osteopetrosis by the absence of both Erlenmeyer flask deformities and “bone-within-bone” appearance. Hypoplasia of the mandible and short bones of the hands and feet with osteolysis of the distal phalanges are characteristic.

Rare autosomal recessive disorder consisting of osteosclerosis, short stature, frontal and occipital bossing, small face with receding chin, short broad hands, and hypoplasia of the nails.

Dysosteosclerosis

Sclerosis of skull, ribs, clavicles and tubular bones similar to osteopetrosis. However, platyspondylia and lucent areas in the expanded diametaphyses allow differentiation.

Autosomal recessive disorder manifested in early childhood with small stature, dental anomalies, abnormal bone fragility, and occasionally neurologic symptoms.

Melorheostosis (Fig. 2.39)

Causes asymmetrical or uniform cortical thickening. Usually limited to one extremity, with a predilection for tubular bones where it presents as continuous or interrupted streaks of sclerotic areas.

When features of melorheostosis are present together with findings of osteopoikilosis and osteopathia striata, then the disorder is often referred to as mixed sclerosing bone dystrophy (Fig. 2.40).

Metastatic disease (extensive) (Fig. 2.41)

Generalized diffuse osteosclerosis.

Most commonly from carcinoma of prostate and breast.

Myelofibrosis (myelosclerosis, myeloid metaplasia) (Fig. 2.42)

Approximately half of the patients develop a diffuse (rarely patchy) osteosclerosis. Ribs, spine, pelvis, humeri, and femur are most often involved. Massive splenomegaly is usually apparent radiographically. Extramedullary hematopoiesis, evident as a paraspinal mass, may be present. Both findings may help to differentiate myelofibrosis from osteoblastic metastases, fluorosis, osteopetrosis, and renal osteodystrophy.

Clinically characterized by hepatosplenomegaly, anemia, thrombocytopenia.

Anemias and leukemias (Figs. 2.43 and 2.44)

Present radiographically more commonly with a loss of bone density and coarsening of the trabecular pattern. Generalized sclerosis may occur, particularly in sickle cell anemia.

Extramedullary hematopoiesis can be associated with all blood disorders. Splenomegaly is usually present except in the adult sickle cell patient (presumably because of multiple splenic infarctions).

Multiple myeloma

Uniform sclerosis is a very rare manifestation.

Characteristic bone marrow and laboratory findings.

Gaucher's disease (Fig. 2.45)

May present in the reparative stage with diffuse osteosclerosis. Characteristic for Gaucher's disease in the femur is the combination of avascular necrosis of the femoral head, Erlenmeyer's flask deformity of the distal end, and multiple osteolytic and/or sclerotic lesions in the shaft.

The radiographic findings described are seen in the chronic form of Gaucher's disease, whereas the acute infantile form is characterized by pathology in the respiratory and central nervous system and is usually fatal in the first year of life.

Erdheim-Chester disease (lipid granulomatosis) (Fig. 2.46)

Symmetric patchy or diffuse osteosclerosis and cortical thickening of the diaphyses and metaphyses of the major long bones, with relative sparing of the epiphyses and axial skeleton, are characteristic.

Affects men and women in the fifth through seventh decade. Xanthomatous patches in the eyelids and mild skeletal pain can be present, but patients may also be asymptomatic.

Paget's disease (Fig. 2.47)

The advanced stage of the polyostotic form may eventually result in a deformed and diffusely sclerotic skeleton. Enlargement of all involved bones by cortical thickening is a radiographic hallmark of the disease.

Common cause of osteosclerosis observed in an asymptomatic patient aged over 40. The radiographic diagnosis is supported by markedly elevated serum alkaline phosphatase and normal serum calcium and phosphorus levels.

Fibrous dysplasia (polyostotic form) (Fig. 2.48)

Similar to Paget's disease. Can present as diffuse sclerosis of the involved bone associated with widening and cortical thickening. The manifestations are predominantly unilateral, and bone deformities are common.

Clinically, “café-au-lait” pigmentations with irregular outline (“coast of Maine” appearance) are found in approximately one third of patients with the polyostotic form. Alkaline phosphatase is normal or only mildly elevated.

Mastocytosis

Can present throughout the skeleton as diffuse sclerosis that is not sharply demarcated from normal bone and often intermingled with osteolytic areas.

See also Table 2.1

Tuberous sclerosis

Can present as diffuse osteosclerosis similar to mastocytosis.

See also Table 2.1

Sarcoidosis

Diffuse osteosclerosis is a rare manifestation.

See also Table 2.1

Renal osteodystrophy (Fig. 2.49)

Features of osteomalacia, hyperparathyroidism, and sclerosis. The latter might be the dominant finding and is often combined with soft tissue calcifications. A “rugger jersey” spine (dense end-plates with relatively lucent centers resulting in a striped appearance of the spine) is most characteristic.

Represents the skeletal response to chronic renal disease of any origin. In primary hyperparathyroidism, sclerosis is virtually limited to cases that are healing.

Oxalosis (Fig. 2.50)