Chapter 46 - Miscellaneous Bone Lesions (CHERI Notes)

Question 1

The most common cause of dwarfism is ___. A congenital hereditary disease of failure of endochondral bone formation.(p.1090)

Answer 1

ACHONDROPLASIA

• the FEMURS and HUMERI are more profoundly affected than the other long bones; although the entire skeleton is abnormal.

Question 2

DIAGNOSIS?
Characteristic finding is that the spine typically has narrowing of the interpeduncular distances in a caudal direction. (p.1090)

Answer 2

ACHONDROPLASIA

• the opposite of normal; in which the interpeduncular distances get progressively wider as one proceeds down the spine.
• the long bones are short but have normal width; giving them a thick appearance.

Question 3

The term______ refers to the lack of blood supply with subsequent bone death and ensuing bony collapse in an articular surface. (p.1090)

Answer 3

AVASCULAR NECROSIS (AVN) or OSTEONECROSIS

• the etiology of AVN is an extensive differential that most commonly includes trauma; steroids; aspirin; renal disease; collagen vascular diseases; alcoholism and idiopathic causes.
• radiographic appearances range from PATCHY SCLEROSIS to ARTICULAR SURFACE COLLAPSE AND FRAGMENTATION.

Question 4

Late and inconstant sign of AVN. (p.1090)

Answer 4

Just before collapse; a subchondral lucency is occasionally seen.

Question 5

___ is extremely valuable in demonstrating the presence and extent of AVN; even when plain films are apparently normal. (p.1090)

Answer 5

MR

• considered to be the most efficacious way to evaluate a joint for AVN.
• it is useful not only in AVN of the hip but also in the knee; wrist; foot and ankle.

Question 6

_____ OSTEOARTHROPATHY is manifested by clubbing of the fingers and periostitis; usually in the upper and lower extremities.; which might or might not be associated with bone pain. (p.1090)

Answer 6

HYPERTROPHIC PULMONARY OSTEROARTHROPATHY

• It is most commonly seen in patients with LUNG CANCER; but many other etiologies have been reported; including bronchiectasis;
  GI disorders and liver disease.

Question 7

The differential diagnosis for periostitis in a long bone without an underlying bony abnormality would include ____. (GIVE 6). (p.1090)

Answer 7

1. Hypertrophic pulmonary osteoarthropathy
2. Osteoarthropathy
3. Venous Stasis
4. Thyroid acropachy
5. Pachydermoperiostosis
6. Trauma

Question 8

_____ is a rare; idiopathic disorder characterized by thickened cortical new bone that accumulates near the ends of long bones; usually only on one side of the bone; and has an appearance likened to “DRIPPING CANDLE WAX”. (p.1090)

Answer 8

MELORHEOSTOSIS

• It can affect several adjacent bones and can be symptomatic

Question 9

The _____ are a group inherited diseases characterized by abnormal storage and excretion in the urine of various mucopolysaccharidoses
such as keratin sulfate (____) and heparan sulfate (______). (p.1090)

Answer 9

MUCOPOLYSACCHARIDOSES;
MORQUIO; HURLER

• these patients have short stature; primarily from shortened spines;
  and characteristic plain film findings
• the pelvis in this disorders is similar in appearance to that of achondroplasts; with wide; flared iliac wings and broad femoral necks.

Question 10

In the spine; patients with ______ have platyspondyly (generalized flattening of the vertebral bodies) with a central anterior projection or “beak” off the vertebral body;
as viewed on a lateral plain film. (p.1091)

Answer 10

MORQUIO

Question 11

______ show platyspondyly with a beak that is anteroinferiorly positioned. (p.1091)

Answer 11

HURLER AND HUNTER

Question 12

A characteristic finding in the hands

in MUCOPOLYSACCHARIDOSES) is a _____. (p.1091

Answer 12

POINTED PROXIMAL FIFTH METACARPAL BASE THAT HAS NOTCHED APPEARANCE TO THE ULNAR ASPECT.

Question 13

_____; also known as DIAPHYSEAL ACLASIA; that
is a not uncommon hereditary disorder that seems to affect multiple members of a family with multiple osteochondromas or exostoses.(p.1092)

Answer 13

MULTIPLE HEREDITARY EXOSTOSIS

• the KNEES are virtually always involved
• under tubulation (a widened diameter of the bone) is invariably present at the site of exostosis.
• the incidence of malignant degeneration in this population has been reported to be as high as 20%; but this is a gross overestimation;
  with malignant degeneration being extremely rare.

Question 14

An ______ is a cartilage-capped bone outgrowth that may be pedunculated or sessile in appearance. (p.1092)

Answer 14

OSTEOCHONDROMA

Question 15

As with SOLITARY OSTEOCHONDROMAS;
the more ____-situated lesions are more prone to undergo malignant degeneration; whereas the more peripheral lesions are less likely to do so. (p._____)

Answer 15

AXIALLY-situated

• The proximal femurs are frequently involved and have a characteristic appearance

Question 16

DIAGNOSIS? (p.1092)
The classically described radiographic appearance is cortically based sclerotic lesion in a long bone that has a small lucency within it that is called the NIDUS.

Answer 16

OSTEOID OSTEOMA

• The etiology of osteoid osteroma is unknown.
• It is a painful lesion that occurs almost exclusively in patients less
  than 30 years of age and is treated successfully with surgical excision
  or thermal ablation

Question 17

It is the ____ that causes the pain and the surrounding reactive sclerosis in OSTEOID OSTEOMA. (p.1092)

Answer 17

NIDUS

• if the nidus is surgically removed or thermally ablated; complete cessation of pain is the rule.
• CT is often very helpful in the demonstrating (of OSTEOID OSTEOMA) the exact location or the nidus.

Question 18

TRUE OR FALSE?
(in OSTEOID OSTEOMA) (p.1092)
- If the nidus of an osteroid osteoma is located in the medullary rather than the cortical portion of a bone; or if it is located in a joint; there is much less reactive sclerosis present.

Answer 18

TRUE

• this gives the lesion a different overall appearance than the more common cortical lesion in that it does not appear as sclerotic.

Question 19

Up to 80% of OSTEOID OSTEOMAS; are located _____. (p.1093)

Answer 19

INTRACORTICALLY;

• with the remainder being in the INTRAMEDULLARY part of a bone.
• rarely; an osteoid osteoma will be present in the periosteum; causing exuberant periostitis

Question 20

TRUE OR FALSE? (In OSTEOID OSTEOMA)

- The nidus itself is usually lucent but often develops some calcification within it.

Answer 20

TRUE

• It then has the appearance of a sequestrum; as seen in OSTEOMYELITIS.
• if the nidus calcifies completely; it blends in with the surrounding sclerosis and cannot be seen on most radiographs.
• Therefore; the diagnosis of an osteoid osteoma in no way depends on seeing a nidus.

Question 21

TRUE OR FALSE?
Because an osteoid osteoma resembles osteomyelitis; regardless of the appearance of the nidus; it can be difficult to differentiate two radiographically. (p.1094)

Answer 21

TRUE

• it cannot be reliably done with plain films; CT or MR
• because the nidus is extremely vascular; it avidly
  accumulates radipharmaceutical bone-scanning agents.
• an osteoid osteoma will have an area of increased
  uptake corresponding to the area of reactive sclerosis but; in addition; will demonstrate a second area of increased uptake corresponding to the nidus (DOUBLE-DENSITY SIGN)

Question 22

TRUE OR FALSE.
Osteomyelitis has a photopenic area corresponding to the plain film lucency that represents an avascular focus of purulent material. (p.1094-1095)

Answer 22

TRUE

• The natural history of an osteoid osteoma is presumed to be spontaneous regression; as they are rarely seen in patients older than the age of 30.

Question 23

______ (aka ________disease); this disorder is manifested by multiple 2-to 3 mm- thick linear bands of sclerotic bone signed parallel to the long axis of a bone.(p.1095)

Answer 23

OSTEOPATHIA STRIATA
(aka VOORHOEVE DISEASE)

• It usually affects multiple long bones and is asymptomatic; hence; it is usually an incidental finding.

Question 24

_________ is a hereditary; asymptomatic disorder that is usually an incidental finding of multiple small (3 to 10 mm) sclerotic bone densities affecting primarily the ends of long bones and
the pelvis. (p.1095)

Answer 24

OSTEOPOIKOLOSIS

• It has no clinical significance other than it can be confused for diffuse osteoblastic metastases.

Question 25

______ is a rare familial disease that is manifested by thickening of the skin of the extremities and face; clubbing of the fingers; and widespread periostitis (p.1096)

Answer 25

PACHYDERMOPERIOSTOSIS - seem to be more common in black patients - the periosteal reaction is similar to that of hypertrophic pulmonary osteroarthropathy; but pachydermoperiostitis is only occasionally painful.

Question 26

______ is a noncaseating granulomatous disease that primarily affects the lungs. - causes a characteristic LACELIKE PATTERN of bony destruction in the hands. (p.1097)

Answer 26

SARCOIDOSIS - when the musculoskeletal system is involved; the HANDS are mainly affected; with the spine and long bones only infrequently involved. - Multiple phalanges are typically affected in either one or both hands. - it is so radiographically characteristic that there is almost no differential diagnosis for this pattern.

Question 27

______ (aka ____); this poorly understood disorder is an idiopathic process that begins with a painful hip with no underlying disorder or other findings other than osteroporosis; which is limited to the painful hip. (p.1097)

Answer 27

TRANSIENT OSTEOPOROSIS OF THE HIP (IDIOPATHIC TRANSIENT OSTEOPOROSIS OF THE HIP) - MR findings are similar to early AVN T1WI: low signal seen througout the femoral head and neck - edema is typically greater than with AVN and no well-demarcated margin is present. - self-limited with full resolution - it tends to occur more often in males.

Question 28

A similar process like transient osteroporosis of the hip which occurs in the KNEE is called ____? (p.1097)

Answer 28

PAINFUL BONE MARROW SYNDROME - seen most commonly in the medial condyle; but can occur laterally or in the proximal tibia adjacent to the joint. - protected weight-bearing is recommended to prevent insufficiency fractures

Question 29

Painful bone marrow edema has been reported in the hip (ITOH); knee; distal clavicle and ankle. It can occur in the several different locations over time or simultaneously and then is called ____. (p.1097)

Answer 29

REGIONAL MIGRATORY OSTEOPOROSIS