Metabolic Bone Disease and Arthritis Review

Compendium of practice questions covering metabolic bone disorders, parathyroid dysfunctions, and types of arthritis based on provided lecture materials.

What percentage of osteoid is composed of collagen?

$$90-95\%$$

Vitamin C is essential for the formation of which three components?

Collagen, osteoid, and endothelial linings

What is the hallmark finding of Hypovitaminosis C?

Spontaneous hemorrhage due to capillary fragility

What symptom is associated with subperiosteal hemorrhage in Scurvy?

Bone pain

Decreased osteoblastic function in adult Hypovitaminosis C resembles which condition?

Osteoporosis

What is the radiographic White line of Frankel?

A dense (bright) Zone of Provisional Mineralization ($ZPM$)

What is Wimbergers ring in pediatric scurvy?

A dense cortical margin of the epiphysis with a radiolucent center

What radiographic sign is characterized by an irregular metaphyseal margin in scurvy?

Corner (angle sign)

What are Pelkan spurs?

Bony protuberances at the margin of the Zone of Provisional Mineralization ($ZPM$)

What is the Trummerfeld (scorbutic) zone?

A radiolucent metaphyseal band directly beneath the Zone of Provisional Mineralization ($ZPM$)

In Hypovitaminosis C, subperiosteal hemorrhage becomes visible during which phase?

Healing

Is Hypovitaminosis C considered a mineralization disorder?

No

What characterizes Osteomalacia in adults?

Qualitatively deficient bone with an abundance of unmineralized osteoid

What are the three metabolic components intimately connected to Osteomalacia?

Calcium, phosphorus, and vitamin D

What ratio is defective in bone softening disorders?

The ratio of mineral-to-osteoid

What is the most common cause of hypophosphatemia leading to Osteomalacia?

Renal disease

What are the pathognomonic features for Osteomalacia described by Looser and Milkman?

Pseudofractures ($Umbauzonen$ or increment fractures)

Where are common locations for pseudofractures in osteomalacia?

Femur, ribs, axillary border of the scapula, and pelvic rami

What skeletal region is NOT an area of discrimination for pseudofractures?

The spine

In rickets, what term describes the enlargement of rib ends?

Rachitic rosary

What is the term for the enlargement around growth plates in rickets?

Trumpeting

What is the hallmark radiographic finding of rickets?

Loss of the Zone of Provisional Mineralization ($ZPM$)

What is the 'paintbrush' appearance in rickets?

Metaphysis flaring

What is the inheritance pattern of X-Linked Hypophosphatemia?

X-linked dominant trait

X-Linked Hypophosphatemia is part of which group of syndromes?

Fanconi syndromes

What genetic disorder is related to low serum alkaline phosphatase?

Hypophosphatasia

What radiographic metaphyseal defect is characteristic of Hypophosphatasia?

Radiolucent metaphyseal defects extending from the growth plate into the metaphysis

What histopathologic changes characterize Hyperparathyroidism ($HPT$)?

Osteoclastic and osteocytic bone resorption with fibrous tissue replacement

What is the radiographic hallmark of Hyperparathyroidism ($HPT$)?

Subperiosteal bone resorption

What is the female-to-male ratio and typical age range for HPT patients?

$3:1$ ratio; $30-50$ years of age

What effect does PTH have on renal calcium and phosphate?

Renal conservation of calcium and inhibition of phosphate resorption

Most cases ($90\%$) of primary Hyperparathyroidism are caused by what?

Adenoma

What is the cause of secondary Hyperparathyroidism?

Persistent hypocalcemia, predominantly from renal disease

Renal Osteodystrophy is a combination of which two conditions?

Renal disease and secondary $HPT$

Where is subperiosteal bone resorption considered pathognomonic for HPT?

Radial aspect of the middle phalanges of the $2nd$, $3rd$, and $4th$ digits

What specific type of resorption occurs within Haversian canals in HPT?

Intracortical bone resorption (linear striations)

What is Salt and Pepper skull?

A granular appearance to the diploic space caused by trabecular bone resorption in $HPT$

What is a Brown tumor ($osteoclastoma$)?

A localized cyst-like bone resorption containing fibrous tissue, blood, giant cells, and hemosiderin

What term describes distal tuft resorption of the fingers?

Acro-osteolysis

HPT can cause diffuse resorption of what dental structure?

Lamina Dura

Chondrocalcinosis is more common in which type of HPT?

Primary $HPT$

Osteosclerosis is more commonly seen in which type of HPT?

Secondary $HPT$

What is the 'rugger-jersey' spine?

Osteosclerosis predominating in the axial skeleton, commonly seen in Renal Osteodystrophy

What does DRSA stand for?

Dialysis Related Spondylo-Arthropathy

How long after starting hemodialysis does DRSA usually develop?

$3-5$ years

What is the most common spinal location involved in DRSA?

Cervical spine

What is the most common cause of Hypoparathyroidism?

Excision or trauma to the parathyroid gland during thyroidectomy

What blood chemistry findings are associated with Hypoparathyroidism?

Hypocalcemia and hyperphosphatemia

What is the major difference between Hypoparathyroidism and PHP?

$PHP$ is genetic (end-organ resistance), whereas Hypoparathyroidism is acquired

What is the characteristic somatotype for Pseudohypoparathyroidism ($PHP$)?

Short stature, obesity, round face, and brachydactyly

What is the defining clinical characteristic of Pseudopseudohypoparathyroidism ($PPHP$)?

Normocalcemia and normophosphatemia

Widespread marrow infiltration by cancer cells in Multiple Myeloma leads to the loss of what?

Bone density

What are the three broad categories of joints based on intervening tissue?

Fibrous, Cartilaginous, and Synovial

What is the 'bare area' of a synovial joint?

The area where the synovial membrane covers bone but is not covered by articular cartilage

What is the primary method of initial imaging for arthritic disorders?

Noncontrast radiograph

How is Rheumatoid Factor ($RF$) defined?

$IgM$ reactive to altered $IgG$

Which group of arthritis is characterized as HLA-B27 positive?

Rheumatoid Variants ($P.A.I.R.$)

Which group of arthritis is characterized as HLA-B27 negative and RF positive?

Rheumatoid Types ($R.S.P.D.T/V.$)

What is the primary target in Rheumatoid Arthritis?

Synovial membrane

What is the difference between Primary and Secondary DJD?

Primary affects predictable joints with no history; Secondary affects unpredictable joints due to previous trauma

What metabolic byproduct is associated with Gout?

Uric acid

What metabolic byproduct is associated with amyloidosis?

Amyloids

All arthritis narrows what radiographic feature?

The joint space

What type of stress leads to Degenerative Joint Disease ($DJD$)?

Mechanical stress (macro or microtrauma)

Inflammation is to Erosion what Osteophytes are to ______.

Degeneration

What are the ABCS of articular disease evaluation?

Alignment, Bone, Cartilage, and Soft tissues

What term is synonymous with subchondral sclerosis in DJD?

Eburnation

What is a geode?

A subchondral cyst related to synovial fluid intrusion into the bone

What are 'joint mice'?

Intra-articular loose bodies

What is the location of Heberden’s nodes?

Distal Interphalangeal ($DIP$) joints

What is the location of Bouchard’s nodes?

Proximal Interphalangeal ($PIP$) joints

At which joint in the wrist is DJD considered a primary finding?

Radioscaphoid joint

Which wrist joint is a primary site for CPPD?

Scaphotrapezium joint

What is buttressing in the context of the hip?

An additional finding of DJD involving thickening of the femoral neck

Which joint in the foot is the most common site for secondary DJD?

$1st$ Metatarsophalangeal ($MTP$) joint

What is Podagra?

Gout in the $1st$ toe

Who first delineated Erosive Osteoarthritis ($EOA$) in $1961$?

Crain

What is the radiographic appearance characteristic of EOA?

Gull wing appearance

What percentage of EOA patients eventually develop Rheumatoid Arthritis?

$$15\%$$

What autoimmune disorder primarily affects the synovium of hands, feet, and the cervical spine?

Rheumatoid Arthritis ($RA$)

At what age does Rheumatoid Arthritis ($RA$) typically peak?

$40-50$ years of age

What is the male-to-female ratio for RA before the age of 40?

$2-3:1$ female predominance

How much joint involvement is required for RA criteria?

Symmetry in $80\%$ of cases

What duration of morning stiffness is required for RA diagnosis?

At least $1$ hour

What is Pannus in the context of RA?

Granulation tissue produced by the synovium that invades the joint

What enzyme produced by the synovium in RA erodes cartilage and bone?

Collagenase

What are 'rat bite' erosions?

Marginal erosions in the bare area of bone

What causes juxta-articular osteopenia in RA?

Hyperemia, disuse, and steroid therapy

What is the cause of ulnar deviation in RA?

Pannus formation and joint destruction

What is the configuration of a Boutonniere deformity?

Extension of the $MCP$, Flexion of the $PIP$, and Extension of the $DIP$

What is the configuration of a Swan Neck deformity?

Flexion of the $MCP$, Extension of the $PIP$, and Flexion of the $DIP$

What is a Mallet Finger?

$DIP$ joint hyperflexion

What is the worst deformity seen in Rheumatoid Arthritis?

Arthritis mutilans

What skin finding is present in $40\%$ of Systemic Lupus Erythematosus ($SLE$) cases?

Butterfly rash

Are the deformities associated with SLE typically reversible?

Yes

In SLE, is the joint considered the primary or secondary target?

Secondary target

What is the medical name for Scleroderma?

Progressive Systemic Sclerosis ($PSS$)

Raynauds phenomenon occurs in what percentage of PSS patients?

$$90\%$$

What does the acronym CREST stand for in PSS?

Calcinosis, Raynaud's, Esophagus, Scleroderma, Teleangiectasia

What distinctive joint destruction is found in PSS of the hand?

Selective destruction of the $1st$ Metacarpocarpal ($MCC$) joint