الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 165 |  |  |
| | | from | 165 | | |
Abstract
Joint arthroplasty is the most frequently performed orthopedic procedure after fracture fixation.The main indication for hip arthroplasty is disabling pain secondary to severe osteoarthritis, inflammatory arthropathy, avascular necrosis, ankylosis secondary to prior infection or surgery, benign and malignant tumors around the hip joint and hip fractures.Local complications associated with a hip prosthesis include: osteolysis, aseptic loosening, infection, heterotopic ossifications, prosthetic and peri-prosthetic fractures, dislocation and subluxation and pseudobursitis. Such complications are common sources of patient morbidity and often necessitate revision arthroplastic surgery. Recognizing and diagnosing these complications are often challenging because the presentations and findings are often nonspecific and frequently subtle. Imaging remains the cornerstone of evaluation.The conventional radiograph is almost all the first modality to be done and the first post-operative radiograph acts as a baseline investigation with which all subsequent radiographs can be compared. The main purpose of the plain film is to assess post-operative alignment, possible fracture or dislocation, moreover it can detect osteolysis around the prosthesis and aseptic loosening.The most common sign of loosening is lucency around the prosthesis together with component migration. The wider and more extensive the lucency, the greater the probability that the prosthesis will be found loose at surgery. Proper evaluation of lucency depends on comparing current films with previous radiographs.Diagnosing infection on Plain film findings is difficult because findings can be normal or can mimic mechanical loosening, however with extensive infection such findings may be impressive including aggressive osteolysis; irregular lucency, may be with periosteal reaction. Other complications such as heterotopic ossification can easily be diagnosed on plain film.Despite the artifacts produced on CT, new techniques have allowed examination of a hip prosthesis. CT can detect lucency more sensitive than conventional radiography, potential loosening of femoral implants before changes are visible on plain radiographs. Infection can be diagnosed by soft-tissue findings such as joint distention and fluid collections in muscles and perimuscular fat. It can also allow early detection of heterotopic ossification and visualization of fractures that have been missed on plain radiography.