Mechanical loosening is the most typical indication for repeat surgery. In some cases, however, the hip prosthesis will loosen earlier, causing pain and/or instability. This type of fracture is usually not displaced and is easily overlooked.Īn artificial hip can generally be expected to last 12 to 15 years. It is usually found at the tip of the prosthetic stem the pelvis is a less common location. Intraoperative or acute periprosthetic fracture is a rare complication in primary cemented prostheses, although it is relatively common in the follow-up of failed hip arthroplasty. Intra-pelvic cement is usually asymptomatic. It occurs most commonly through a defect in the medial acetabular wall. Polymethylmetacrylate cement ex-trusion is another acute complication. CT or ultrasound-guided joint aspiration or synovial biopsy can detect about 75% to 95% of prosthetic infections. Infection may also be present when postoperative imaging shows lytic lesions, progressive interfacial widening, periosteal reaction, or smooth endosteal scalloping with cement lucency, as is typical in aseptic loosening or aggressive granulomatosis disease.Įxtensive bone destruction, air in the soft tissue and/or joint, extensive or aggressive periosteal reaction, and a wide or irregular lucent zone are the most suspicious radiological signs of infection. Sinus tract formation or bone destruction may occur with more aggressive infectious agents. Radiological findings in patients with indolent infection can be unremarkable or show minimal changes, 3,4 and a normal-appearing radiograph does not exclude infection. Infection, which occurs in 1% of artificial joint replacements, can be a serious early complication, or it may appear months or even years after surgery. Well-defined areas of lucency around the prosthesis usually indicate bone resorption destruction (histiocytic response), but aseptic loosening and infection can demonstrate a similar appearance. Lucency that is less than 2 mm in width should be followed on consecutive plain films for progression. Lucency of 2 mm or more at the bone-ingrowth surface with cement-free arthroplasty is considered abnormal. The line is delimited from adjacent bone by a thin line of sclerosis, the demarcation line. This is a normal finding that represents fibrous tissue and is stable over time.

Radiography of cemented prostheses will generally show a thin lucent line, less than 2 mm wide, along the cement-bone interface. Leg length, acetabular inclination, and varus or valgus stem position should be evaluated and compared with the immediately postoperative study. It is important that the entire prosthesis is included on two orthogonal x-rays. Our standard follow-up imaging evaluation of hip arthroplasty begins with routine plain-film radiography. Acetabular fixation may be completed with spikes or screws. Cement-free prostheses are coated to provide a porous surface that enables fixation by bone ingrowth. Polymethylmethacrylate cement, used for filling the space between the bone and the prosthesis, provides the necessary fixation and force distribution. Hip replacements can be cemented at the acetabular and/or femoral stem. Late complications, some of which occurred as long as 15 years after surgery, have included aseptic loosening, aggressive granulomatosis, stress shielding, heterotopic ossification, luxation, bone fractures, and prosthetic fracture. The acute complications included infection, cement extrusion, periprosthetic fracture, and immediate dislocation. This follow-up is most frequently done using plain-film x-rays, occasionally with ultrasound or CT, and, rarely, with MRI.Ī retrospective review of 1854 patients (36 to 91 years old male/female ratio 1:3) who underwent hip arthroplasty at our hospital in an eight-year period revealed that 5.2% experienced acute complications, and 9.2% developed complications later. All patients undergo imaging examinations immediately after surgery, at six months, and then yearly or when necessary. Surgeons have used a variety of materials to replace the hip joint, including metal, polyethylene, and ceramics. Our hospital has performed more than 200 hip replacements annually over the past 14 years. As surgical techniques subsequently evolved, radiological criteria for evaluating prosthesis components and their complications adapted accordingly. The first hip replacements were performed about 50 years ago. Degen-erative problems remain the main indication for this procedure, although patients with femoral head avascular necrosis, rheumatoid arthritis, complications of fracture, and hip dysplasia may also require hip replacement surgery. Hip replacement procedures are becoming in-creasingly common as the population ages.

Normal xray hip 14 years old