Data Trace Editor – Discussion: – see metastatic carcinoma; – will also produce increased bone density – 30% of lung mets will show increased bone density on radiographs; – avgerage life expectancy w/ metastatic lung Ca + pending pathologic frx is 3 months (vs. 18 months in breast ca); – … Read more
– Discussion: – bone scans tend to be hot (unlike multiple myeloma); – bone lesion may be less likely to cause pathologic fractures than other metatsatic lesions; – if bone lesions are asymptomatic, consider non operative treatment; – associated features include lymphadenopathy or splenomegaly; – evaluate cervical, … Read more
Discussion: – pathologic fractures through lesions w/ increased density is rare; – lesion should be irradiated if the patient has pain, & internal fixation is indicated only if the pain persists after completion of the irradiation and no other cause is found; – PSA: … Read more
– Discussion: – displacement of metacarpal shaft fractures is prevented by intermetacarpal ligaments and intrinsic muscles; – the border metacarpals (thumb, index, and little) are not supported as well as the ring and long metacarpals and are therefore more likely to displace; – effect of shortening: … Read more
– See: Characteristics of Metals and Implants: – Fratigue Fracture: – frx or break or a metal caused by repetitive applications of loads in between the fatigue limit and the Yield Strength; – Fatigue Limit: – load that a metal can endure indefinitely without bending or breaking when subjected to cyclic bending; … Read more
– Advantages: – larger heads helps avoid dislocation: – avoidance of screws – larger heads allows greater ROM – Disadvantages: – metallosis – contraindictated in renal insufficiency; – Levels: – normal cobalt: – mean serum cobalt level of 0.24 µg/L (range: 0.08 to 0.50 µg/L) – highest safe level: … Read more
– Discussion: – femoral component is made of chrome colbalt alloy w/ its proven wear characteristics articulating with high density poly ethylene; – tibial & patella components are metal backed w/ titanium alloy; – enhance fatigue strength of titanium decreases potential for stress fracture of the metallic tibial tray; – in metal back patella component, the … Read more
– See: – Epiphyseal Artery – Nutrient Artery – Periosteal Artery – Discussion: – metaphyseal portion of long bone contains numerous small channels; – through these channels pass vessels that enter marrow cavity to anastomose w/ vessels derived from nutrient artery; … Read more
– Discussion: – heterogeneous group of intrinsic dysplasias characterized by x-ray changes in the metaphysesof the short and long tubular bones (epiphyses remains normal); – defect appears to lie in proliferative & hypertrophic zones of physis; – hypercalcemia is common; – diff dx: … Read more
– See: Extra-articular Thumb Metacarpal Fractures – Discussion: – interosseous muscles & intrinsically strong carpometacarpal capsular and interosseous ligaments provide intrinsic stability to extra-articular fractures at the metacarpal bases; – mechanism of frx of little CMC: – stability of CMC joint derives from articulation w/ carpal … Read more