Bone and Soft-Tissue Disorders
Source:- dialysate containing a high concentration of aluminum, total parenteral nutrition, aluminum salts phosphate-binding antacids (to control hyperphosphatemia)
- aluminum serum level >100 ng/mL
- osteopenia → pathologic fractures
- signs of osteomalacia (>3 insufficiency fractures with predominant involvement of ribs)
- widening of physis, fraying of metaphyses of long bones
- avascular necrosis
- lack of osteosclerosis
- little evidence of subperiosteal resorption
- rickets, osteomalacia, osteoporosis
- calvarial thickening + thickening of heel pad
= inorganic phosphates administered orally / IV
Use: decrease of bone pain + reduced complications in patients with metastatic lytic lesions, malignancy-induced hypercalcemia, multiple myeloma, Paget disease, osteoporosis
Pathophysiology: inhibition of endothelial proliferation → interruption of intraosseous circulation
- Long bones
- bone-within-bone = bandlike metaphyseal sclerosis (in the maturing skeleton)
- atypical low-energy fractures:
- Location: proximal third of femur, distal to lesser trochanter, proximal to supracondylar flare
- transverse minimally comminuted fracture
- fracture fragment with medial spike / beak
- medial periosteal stress reaction + unicortical nipple (= focal thickening of lateral cortex)
- Osteonecrosis of mandible
Location: mylohyoid ridge of mandible
Cause: spontaneous (increased risk with concurrent steroid therapy) / precipitated by trauma (tooth extraction)
May be associated with: infection by actinomyces- painful / asymptomatic (occasionally)
- poorly marginated diffuse area of low attenuation with bilateral symmetric sclerosis
- (most common cause of drug-induced) osteoporosis
- insufficiency fractures
- avascular necrosis + arthropathy
Use: removal of excess iron stores from multiple transfusions (treatment of severe β-thalassemia)
- flattening of vertebrae → lower height percentile
- irregular thickened cupped metaphyses (similar to rickets)
Source of fluorides: high natural content in drinking water (parts of southeast Asia, South Africa); welding / manufacture of aluminum; medical drug therapy
- sclerosis with granular pattern + thickened trabeculae
- ossification of ligamentous insertions
- osteophytic outgrowths around joints
- increased bone fragility
- diffuse periostitis
= Lead poisoning = plumbism
Source: paint, home-distilled liquors, folk remedies, cosmetics, industrial materials
Path: lead concentrates in metaphyses of growing bones (distal femur >both ends of tibia >distal radius) leading to failure of removal of calcified cartilaginous trabeculae in provisional zone
- loss of appetite, vomiting, constipation, abdominal cramps
- peripheral neuritis (adults), meningoencephalitis (children)
- anemia; lead line at gums (adults)
- bands of increased density at metaphyses of tubular bones (only in growing bone):
- single transverse line of dense band
- bone-in-bone appearance
- elevated serum levels (70–80 mg/dL)
- lead lines may persist
- clubbing if poisoning severe (anemia)
DDx:
- Healed rickets
- Normal increased density in infants <3 years old
- Hypervitaminosis D
- Healing leukemia
- Scurvy
= dihydrofolate reductase inhibitor most often used in children for treatment of ALL / osteosarcoma / brain tumor
Methotrexate Osteopathy = syndrome that consists of (1) bone pain (2) osteopenia (3) pathologic fractures
◊Radiographic findings similar to scurvy:
- osteopenia:
- metaphyseal band of demineralization (simulating recurrent leukemia)
- broadening + increased density of the zone of provisional calcification
- sharply outlined epiphyses
- “corner” sign, ring epiphysis
- pathologic insufficiency fractures (most often metaphyseal)
- impaired healing of fractures
- NO massive subperiosteal hemorrhage
Use: maintain patency of ductus arteriosus
- periostitis = periosteal new bone growth
Location: symmetric involvement of long bones, ribs, clavicle, scapula, mandible
DDx: infantile cortical hyperostosis (Caffey disease); syphilis; effect of interleukin-11 therapy; scurvy; hypervitaminosis A
- skeletal hyperostosis:
- axial skeleton (esp. C-spine)
- anterior vertebral osteophytes
- ossification of anterior longitudinal ligament
- osseous bridges between vertebrae
- appendicular skeleton
- calcification / ossification of coracohumeral ligament
- enthesopathy
- axial skeleton (esp. C-spine)
DDx: Diffuse idiopathic skeletal hyperostosis
- muscle edema (= acute myositis)
- cortical thickening of tubular bones
- cupping + fraying of metaphyses
- irregularity of growth plates
- premature fusion of ossification centers
DDx: Caffey disease (mandibular involvement, fever, >4 months of age)
- generalized osteoporosis
- metastatic calcifications in periarticular soft tissues