Pathologic Fractures Flashcards
pathologic fracture definition
occurs when normal integrity and strength of bone have been compromised by invasive or destructive processes
causes of pathologic fractures (7)
neoplasm, necrosis, metabolic disease, disuse, infection, osteoporosis, iatrogenic
are fractures more common in benign or malignant tumors?
benign
most common locations of pathologic fractures secondary to benign tumors in children (2)
humerus, femur
most common benign tumors associated with pathologic fractures in children (4)
unicameral bone cyst, non-ossifying fibroma, fibrous dysplasia, eosinophilic granuloma
primary malignant tumors associated with pathologic fractures (6)
osteosarcoma, ewing sarcoma, chondrosarcoma, malignant fibrous histiocytoma, fibrosarcoma, etc
suspect a primary tumor in younger patients with aggressive-appearing lesions (3 characteristics)
poorly defined margins (wide zone of transition), matrix production, periosteal reaction
do benign or malignant tumors have antecedent pain before fracture
more often malignant
mechanism of injury in pathologic fractures
may be result of minimal trauma or normal activity
clinical history eliciting suspicion for pathologic fracture (5)
normal activity or minimal trauma, excessive pain at the site of fracture prior to injury, patients with known primary malignant disease or metabolic disease, history of multiple fractures, risk factors (smoking/environmental exposure to carcinogens)
additional physical exam (3)
adjacent peripheral lymph nodes, check for masses, other painful areas for impending fractures
laboratory evaluation (8)
cbc w diff, red blood cell indices, and peripheral smear; esr; chem panel; ua; stool guaiac; spep/upep; 24-hr urine hydroxyproline; specific tests
most specific laboratory tests for suspected pathologic fracture (4)
thyroid function tests, carcinoembryonic antigen, parathyroid hormone, prostate-specific antigen
abnormal lab finding in osteoporosis
none
abnormal lab finding(s) in osteomalacia
low urine calcium
abnormal lab finding(s) in hyperparathyroidism (1+/-2)
high urine calcium +/- high serum calcium/low serum phosphorus
abnormal lab finding(s) in renal osteodystrophy (3)
low serum calcium, high serum phosphorus, high serum alkaline phosphatase