The value of contrast arthrography in assessing loosening of symptomatic uncemented total hip components

Twenty-five patients with symptomatic uncemented total hip components were studied with contrast arthrography prior to surgical exploration. All but one had uncemented femoral stems and 16 had an uncemented acetabular component. As judged by the findings at surgery, on the femoral side the sensitivity, specificity, and accuracy of arthrography were 57%, 60%, and 58% respectively. There was a relatively high incidence of both false positives (17%) and false negatives (25%). On the acetabular side sensitivity, specificity, and accuracy were 29%, 89%, and 62.5%. False negatives were common (31%), while there was only one false positive. The results in this small series show that arthrography has distinct limitations in identifying the fixation status of uncemented total hip components.     

Radiophosphate evaluation of loose hip prostheses

There were 23 patients who had revisions of their failed hip arthroplasties and a prior radiophosphate assessment of the joint components. In this selected group of patients the true positive incidence of abnormal scintigraphic findings for femoral component loosening was 19 out of 20 (95%) and the true negative incidence was two out of two by the criteria adopted. The true positive incidence of such findings, indicating acetabular component loosening, was seven out of seven, and the true negative was nine out of 10. Some of these patients also had contrast arthrography and the incidences of true positive and true negative findings for femoral component loosening were seven out of 15 (47%) and one out of one, respectively. Prediction of the status of the acetabulum was poorer using this technique with true positive and true negative incidences of four out of nine and two out of five, respectively.     

False-positive radionuclide arthroscintigraphy with a porous-coated total hip prosthesis.

The evaluation of a painful hip prosthesis for suspected loosening frequently requires a multi-modality approach. Radionuclide arthroscintigraphy is a valuable adjunct to contrast arthrography, demonstrating greater sensitivity than contrast arthrography in detecting loosening of the femoral component of the prosthesis. Despite its reliability in the evaluation of cemented hip prostheses, the value of arthroscintigraphy in patients with uncemented or porous-coated prostheses is undetermined. The case of a false-positive radionuclide arthroscintigram in a patient with an uncemented prosthesis is reported. The literature is briefly examined, and the potential implications regarding interpretation of arthroscintigraphy in patients with porous-coated prostheses are discussed.     

Arthroscintigraphic evaluation of the painful total hip prosthesis

Arthroscintigraphy was performed in 19 patients with a painful total hip prosthesis by injecting both Tc-99m sulfur colloid and iodinated radiographic contrast material intra-articularly. Scintigraphic and radiographic results correlated exactly in 15 patients, with one false-negative scintigram, one false-positive scintigram, and one false-negative arthrogram. One patient was evaluated by scintigraphy alone. Although arthroscintigraphy is potentially more sensitive than conventional arthrography in the detection of femoral component loosening, acetabular component loosening cannot be evaluated by scintigraphy alone. A combination of scintigraphy and conventional arthrography appears to be the most accurate imaging method in the evaluation of hip prosthesis loosening.     

Radiological evaluation of painful total hip replacement

Ninety-four cases of clinically failed, cemented, total hip prostheses requiring surgery were reviewed to determine the accuracy of preoperative plain radiography, culture of aspirated fluid, arthrography, and bone scanning. When radiopaque cement had been used to embed the prosthesis, plain radiography was highly accurate in detecting a loose femoral component, less so in detecting a loose acetabular component. Culture of aspirated fluid was accurate in diagnosing infection. A positive arthrogram identified loosening with good accuracy; however, a negative arthrogram did not reliably exclude loosening. 99mTc bone scans frequently differentiated loosening from loosening with infection. The suggested sequence of diagnostic tests is plain radiography followed by bone scanning. If the bone scan shows diffuse augmented uptake, culture of aspirated fluid followed by arthrography is indicated.     

Evaluation of metallic osseous implants with nuclear medicine

Nuclear medicine has proven to have a valuable role in the evaluation of osseous metallic implants, particularly with joint prostheses, but can assist with evaluation of other appliances as well. The nuclear arthrogram has become an invaluable adjunct to simultaneously performed radiographic contrast arthrography. This application has been best evaluated in what is one of the most common of orthopedic prosthesis problems, namely, loosening of total hip prostheses. Experience indicates that both sensitivity and specificity of loosening of the femoral component can be increased to over 90% through combined use of nuclear with radiographic contrast arthrography. Furthermore the combination of routine skeletal scintimaging with the nuclear arthrogram adds a significant dimension to precise localizing of the nuclear arthrographics agent In-111 chloride. Nuclear medicine also plays an important role in further evaluating the presence of infection associated with metallic implants with In-111 WBC preparations being superior to Ga-67 as the radiopharmaceutical tracer. Infection has been detected with a sensitivity of 73% and a specificity of 93% in our series using combined In-111 WBC and simultaneous skeletal imaging with conventional Tc-99m MDP. Acute infections are more readily identifiable than chronic in association with prostheses.     

Radiography, radionuclide imaging, and arthrography in the evaluation of total hip and knee replacement

Twenty patients with 21 total joint replacements including 17 hips and 4 knees were studied by plain film radiography, radionuclide imaging, and subtraction arthrography to evaluate these procedures for assessing prosthetic complications. Surgery was performed in 14 patients and confirmed loosening of 8 femoral and 7 acetabular hip prosthesis components and 1 femoral and 4 tibial knee prosthesis components. Plain films suggested loosening of only 9 hip components and no knee components. In contrast, radionuclide imaging and subtraction arthrography were considerably more effective in demonstrating loosening as well as other causes of the painful total joint prosthesis.     

Colour Doppler ultrasound assessment of well-functioning mature arteriovenous fistulas for haemodialysis access

OBJECTIVE: To summarize and compare the diagnostic accuracy of contrast and subtraction arthrography in the assessment of aseptic loosening of total hip arthroplasties. DESIGN: This meta-analysis was performed using methods described by the Cochrane Methods Group on Systematic Reviews of Screening and Diagnostic Tests. We included original, English-language papers published between January 1975 to October 2004 that examined contrast-enhanced arthrography with or without subtraction for diagnosis of loosening of total hip prostheses. A qualitative and quantitative analysis was performed by two investigators. RESULTS: With regard to the acetabular component, pooled sensitivity and specificity for contrast arthrography was 70% (95% confidence interval, 52-84) and 74% (95% CI, 53-87), respectively. Subtraction arthrography had a significantly higher sensitivity of 89% (95% CI, 84-93) (p=0.01), with a similar specificity of 76% (95% CI, 68-82). For the femoral component, pooled sensitivity and specificity for contrast arthrography were 63% (95% CI, 53-72) and 78% (95% CI, 68-86). Pooled estimates for subtraction arthrography revealed a significantly higher sensitivity of 86% (95% CI, 74-93) (p=0.003). Specificity was 85% (95% CI, 77-91) and was similar to the data of contrast arthrography (p=0.23). CONCLUSION: Using the present data we found that the subtraction arthrography is a sensitive technique for detection of loosening of total hip prostheses, offering added value over contrast arthrography, especially for evaluation of the femoral component.     

Cutaneous fistula communicating with the hip in a patient with a painful total hip prosthesis. Demonstration by radionuclide arthrography

Radionuclide arthrography is becoming increasingly useful in the evaluation of femoral component loosening in patients with a painful total hip prosthesis. Additional potential advantages of radionuclide arthrography include detection of abnormal communications with the hip, such as bursae, abscess cavities, and fistulas. A case of cutaneous fistula communicating with the hip in a patient with loosening and infection of the femoral component of the total hip prosthesis that is clearly demonstrated by radionuclide arthrography is presented.     

Arthrography in total hip prosthesis complications.

Previous reports have stressed the value of hip arthrography primarily in determining the presence of loosening of the total hip prosthesis. Although loosening is a common complication and frequently associated with infection, other complications producing a painful hip prosthesis exist and are demonstrable by arthrography. Since the etiologies of these are as diversely different as the treatment, the hip arthrogram is advocated as an integral part of the diagnostic approach to the patient with a painful hip prosthesis in order to assess the specific complication and determine the therapeutic approach.     

Combined nuclear and digital subtraction contrast arthrography in painful knee prosthesis.

The evaluation of a painful knee prosthesis remains a difficult problem for both orthopaedic surgeons and radiologists. We have compared digital subtraction arthrography with nuclear arthrography in 7 patients with a painful knee prosthesis. Three patients showed a loose tibial component, demonstrated by both digital subtraction and nuclear arthrography. All 3 underwent revision of their prosthesis. One patient had an equivocal digital subtraction arthrogram and negative nuclear arthrogram, while both studies were negative in the 3 remaining patients. Nuclear arthrography is a simple procedure and can provide useful additional information when combined with digital subtraction arthrography.     

Arthrographic study of painful total hip arthroplasty: refined criteria

The criteria for a diagnosis of loosening or infection of hip arthroplasties on arthrographic study were further refined by a retrospective review of 178 arthrograms representing 170 patients. The 97 arthroplasties that were surgically evaluated form the basis of this report. With the refined criteria, subtraction arthrography had a sensitivity of 96% and specificity of 92% for demonstrating loosening of the femoral component and a sensitivity of 97% and a specificity of 68% for demonstrating loosening of the acetabular component. Pseudocapsule size and the presence of bursae were important factors influencing arthrographic interpretation. Arthrographic findings of pseudocapsule irregularity and the presence of nonbursal cavities were suggestive of infection but were not sensitive or specific. Laboratory evaluation of aspirated material was a more reliable predictor of infection, although its sensitivity was only 71%.     

Combined nuclear and digital subtraction contrast arthrography in painful knee prosthesis

The evaluation of a painful knee prosthesis remains a difficult problem for both orthopaedic surgeons and radiologists. We have compared digital subtraction arthrography with nuclear arthrography in 7 patients with a painful knee prosthesis. Three patients showed a loose tibial component, demonstrated by both digital subtraction and nuclear arthrography. All 3 underwent revision of their prosthesis. One patient had an equivocal digital subtraction arthrogram and negative nuclear arthrogram, while both studies were negative in the 3 remaining patients. Nuclear arthrography is a simple procedure and can provide useful additional information when combined with digital subtraction arthrography. Offprint requests to: F.W Poon     

Contrast reaction from hip arthrogram

Arthrography is considered a safe procedure with rare reactions to intra-articular contrast administration. Although the use of intra-articular contrast carries a small risk of reaction, no prior serious complications had been encountered in our experience with arthrography. We report a patient’s prolonged reaction to contrast media after an arthrogram of the hip. Literature review demonstrated no prior report of contrast media reactions to hip arthrography. Therefore, we decided to review the literature and report our case.     

Imaging of infected total arthroplasty with Tc-99m-labeled antigranulocyte antibody Fab'fragments

OBJECTIVE: The objective of this study was to evaluate the diagnostic accuracy of Tc-99m-labeled antigranulocyte antibody Fab' fragments in infected total arthroplasty. MATERIALS AND METHODS: A total of 38 immunoscintigrams were evaluated retrospectively with 15 to 25 mCi Tc-99m-labeled antigranulocyte antibody-Fab' fragments. The final diagnosis was assessed by articular puncture or intraoperative sampling. RESULTS: In the total hip replacement group the authors found 10 true positives, 7 true negatives, 8 false positives, and 1 false negative; and in the total knee replacement group they found 4 true positives, 8 true negatives, and no false positives or false negatives. They also found a sensitivity of 93%, a specificity of 65%, and a positive predictive accuracy of 63%. There was a negative predictive accuracy of 94%. CONCLUSION: The high negative predictive accuracy in the whole group suggests that the scan can be used to exclude infection in most cases. Negative results with a high clinical suspicion merits further investigation. A positive result will require further correlative imaging, especially for total knee replacement.     

Digital subtraction arthrography in preoperative evaluation of painful total hip arthroplasty

 Objective. The objective of this clinical study was to define the diagnostic value of plain radiography, digital subtraction arthrography and two-phase bone scintigraphy in patients with clinically loose or infected hip prostheses. Design. Digital subtraction arthrograms, scintigrams and plain radiographs of 70 consecutive patients who underwent revision hip arthroplasty were scored individually and in masked fashion for the presence or absence of features indicating loosening of femoral and/or acetabular components. The operative findings acted as the gold standard. Results. Digital subtraction arthrography was best (P<0.001) for predicting a loose acetabular component, while no significant additional predictive value was found for plain radiographs (P=0.24) and scintigraphy (P=0.27). Digital subtraction arthrography was also the most important modality for predicting a loose femoral component (P=0.001), while the plain radiograph was of significant (P=0.04) additional value and scintigraphy was of no additional value (P=0.13) on multivariate analysis. Conclusion. Digital subtraction arthrography gives the best results in the prediction of loosening of acetabular and femoral components. Plain radiographs give additional information on loosening of the femoral component, but scintigraphy offers no additional advantage.     

Lymphatic opacification in the prosthetic hip

A retrospective analysis of 52 patients with hip pain following total hip replacement was made. Each of them was evaluated by plain radiographs, technetium 99m pyrophosphate scans, arthrography with plain film subtraction technique, and culture of joint fluid. In 30 cases there was evidence of prosthetic loosening, and in 21 of these lymphangeal opacification during arthrography was seen. In 15 cases with lymphongeal opacification the diagnosis of prosthetic loosening was subsequently confirmed by prosthetic revision. In none of the 22 cases in which no evidence of prosthetic loosening was seen was there lymphatic opacification. It is concluded that lymphatic opacification during arthrography for pain following total hip prosthesis is a valuable ancillary sign of loosening.     

The use of [18 F]fluorodeoxyglucose positron emission tomography to differentiate between synovitis,loosening and infection of hip and knee prostheses

Pain is a common unspecific symptom in orthopaedic prosthetics. The accurate differentiation between synovitis, loosening or infection is often difficult with conventional X-rays, arthrography or bone scintigraphy. Because of the high glucose uptake of inflammatory cells, [18F]fluorodeoxyglucose (18F-FDG) is an appropriate tracer for the evaluation of suspected inflammation or infection. In this preliminary study we describe 18F-FDG PET findings in patients referred for evaluation of painful hip or knee prostheses. We studied 23 patients with 28 prostheses, 14 hip and 14 knee prostheses, who had a complete operative or clinical follow-up. 18F-FDG PET scans were obtained with an ECAT EXACT HR+ PET scanner. High glucose uptake in the bone prostheses interface was considered as positive for infection, an intermediate uptake as suspect for loosening, and uptake only in the synovia was considered as synovitis. The imaging results were compared with operative findings or clinical outcome. PET correctly identified three hip and one knee prostheses as infected, two hip and two knee prostheses as loosening, four hip and nine knee prostheses as synovitis, and two hip and one knee prostheses as unsuspected for loosening or infection. In three patients covered with an expander after explantation of an infected prosthesis PET revealed no further evidence of infection in concordance with the clinical follow-up. PET was false negative for loosening in one case. Our preliminary results suggest that FDG PET could be a useful tool for differentiating between infected and loose orthopaedic prostheses as well as for detecting only inflammatory tissue such as synovitis.     

Loose hip prosthesis. Appearance in radionuclide arthrography

Radionuclide arthrography has been found to be valuable in the diagnosis of a loose hip prosthesis. The appearance of one normal case with no loosening and two abnormal cases with loosening of femoral and acetabular components are described. To diagnose this difficult problem, radionuclide arthrography should be used more frequently.     

The metal-cement interface in total hip prostheses.

Serial radiographs of 101 total hip arthroplasties were reviewed to evaluate the clinical significance of lucent zones at the femoral metal-cement interface. Such lucent zones were identified in 19 hip prostheses, but only in four was there clinical evidence of infection loosening of the prosthesis. The remaining 14 patients (15 prostheses) were followed for periods ranging from 18 months to 5 years; none had complications despite the development of these lucent zones. Microdensitometry confirmed the existence of a true lucent zone in most cases, but in several the apparent lucency was due to the Mach effect. While progressive widening of the lucent zone or a lucency measuring greater than 2 mm in width should prompt careful clinical evaluation for evidence of infection or loosening, our data indicate that such complications need not necessarily be present.