الفهرس 
Anatomy of hip jointOnly 14 pages are availabe for public view
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Abstract
Total hip arthroplasty is one of the most clinically efficacious and cost-effective medical interventions.
Surgeons and Radiologists have continued to produce a tremendous amount of research data related to clinical outcomes, biomaterials, surgical techniques, imaging and treatment of complications, and socioeconomic analysis.
For example between April 2004 and April 2005, fifty-five reports related to total hip arthroplasty were published in The Journal of Bone and Joint Surgery (American Volume), 140 were published in the Journal of Arthroplasty, and sixty-eight were published in Clinical Orthopaedics and Related Research.
Many models of hip prostheses can be used in the procedure. For better orientation I divided the currently used total hip prostheses according to the materials used for their joint surfaces into
• conventional (metal ball on polyethylene cup)
• metal-on-metal, (metal ball on metal cup)
• ceramic (ceramic ball on ceramic or polyethylene cup) .
Every total hip prosthesis must be fixed to the skeleton by one of the following methods:
• cemented total hip = the prosthesis is secured to the skeleton by a substance called bone cement
• cementless total hip - the prosthesis is directly impacted into the skeleton and secured by a (successive) ingrowth of the bone into the surface of the prosthesis.
Ninety percent of patients have good or excellent results after total hip arthroplasty. Those with persistent postoperative pain after cemented prostheses have infection, or, less commonly, have heterotopic bone formation. Studies of patients with uncemented prostheses indicate that pain occurring after an asymptomatic period suggests possible loosening. While patients with loosening or infection usually (but not always) have pain .
A careful history and physical examination is an essential cornerstone of the workup after THA. Basic laboratory tests and plain radiographs are a standard part of the routine basic workup.
The differential diagnosis of complications includes superficial and deep infections, heterotopic bone formation, mechanical aseptic loosening, prosthetic or periprosthetic fracture, dislocation, and foreign-body granulomatosis. It can often be narrowed considerably based on this information alone.
Joint aspiration, nuclear medicine scans, CT, MRI, and PET can be performed as necessary to complete the workup.
Literature from the field of evidence-based medicine suggests that each test result will move the chance of a given diagnosis from a pretest probability to a post-test probability. By moving from test to test, once a given threshold of certainty is crossed, appropriate treatment can then begin.
The initial films serve as a baseline study and are used as reference films for comparison with all future studies, since sequential radiography is the most valuable method for detecting complications. The initial postoperative films are obtained to look for possible dislocation or fracture and to see if the prosthesis is good positioned.
Although the differential diagnosis of post arthroplasty pain is broad, mechanical and aseptic loosening are the most common conditions that confront the clinician and radiologist. Because aseptic loosening is a diagnosis of exclusion, ensuring that infection is not the cause of loosening is necessary, and cross-sectional imaging, scintigraphy, and arthrocentesis may be required.
Improvements in metal artifact reduction protocols mean that diagnostic CT and MRI examinations can be produced on standard equipment available in most radiology departments.
Magnetic resonance imaging has become a very useful and important adjuvant imaging modality in the evaluation of patients with total hip arthroplasty at the Hospital . Its role in the evaluation of periarticular soft tissues including muscle, tendon, and neurovascular structures has led to a significant increase in the utilization of MR imaging in the evaluation of postoperative complications related to total hip arthroplasty.
A large number of techniques are available for evaluating total hip arthroplasties. Radiographs, however, remain the standard imaging modality. CT and MRI hold potential for assessing complicated hip arthroplasty.