(see also: Acetabular Component Menu) Acetabular Component press fit components » note whether acetabular component is hemispheric or non-hemispheric; non hemispheric components (ie over sized components or components with a peripheral flare) may be more appropriate for protrusio or for situations where acetabulum will be medialized where as hemisperic components may be more appropriate for … Read more
Total Hip Replacement Menu » Acetabular Component Revision » Discussion indications: salvage device for use in cases of pelvic discontinuity where a stable socket cannot be wedged between the anterior and posterior columns; classification of bone defects and bone grafting options: in almost every case, bone graft is morcelized and placed behind the cup; in … Read more
THR menu acetabular component posterior column fracture Discussion (see also: classfication and bone graft options) condition in which superior aspect of pelvis is separated from inferior aspect because of bone loss or a fracture through acetabulum; most discontinuities represent unhealed transverse acetabular fractures which occurr through areas of pelvic bone loss; in the study by … Read more
THR menu acetabular component revision acetabular component Socket (Hip Center) Location if opposite hip is normal, it may be used as a template; normal hip center should be restored when possible (this will reduce joint reactive forces); generally the the component is placed as far medially and as far inferiorly as possible; management of superior … Read more
THR menu / Revision THR acetabular component Discussion note that some of the problems seen in dysplasia are frequently encountered in revision THR; indications for acetabular revision: sepsis, component malposition, impingement, polyethylene wear, pelvic osteolysis, recurrent dislocation, progressive protrusio, and component loosening; evaluation of the painful THR examination: examination for loosening previoius incisions; contracture of … Read more
Discussion restoration of normal hip center in acetabular reconstruction encourages restoration of normal biomechanics; placing the socket laterally creates increased joint reactive force, and placing it directly superior requires the use of a long neck prosthesis to restore abductor moment arm; long neck prosthesis will develop increased lateral bending stresses, adapting to the activities of … Read more
(see also: acetabular component Loosening of Press Fit Acetabular Components (press fit acetabular components) normal bone ingrowth generally for bone ingrowth to occur, the component must lie with 50 micrometers of the acetabulum, inorder for host bone ingrowth to occur; as noted by Bloebaum RD, et al (1997), bone ingrowth into component averages only 12%, … Read more
Discussion total absence of the thumb may be an isolated anomaly, but it is often associated with some other congenital malformation; absent thumb may be inherited as autosomal dominant or may be sporadic; absent thumb is frequently observed in Holt-Oram syndrome, Fanconi’s anemia, and ring D chromosome abnormalities; absent radius is almost always associated with … Read more
(see also: AKA Prosthesis, Amputations in the Diabetic Patient Discussion average AK amputee walks 43% slower and expends 89% more kcal/min than the normal person; if proximal circulation is adequate, a longer anterior muscle flap may be left and the combination myodesis- myoplasty technique is used; ability to ambulate with a prosthesis depends heavily … Read more
Discussion it is important that knee joint is extended throughout stance phase; this means that the components are assembled so that a straight line extended fromthe "trochanter" will pass anterior to the knee and through the ankle; friction is adjusted to help control the amount of knee flexion and to help decelerate the shank; mechanical … Read more