Prospective study of sequential technetium-99m phosphate and gallium imaging in painful hip prostheses (comparison of diagnostic modalities)

Twenty-two painful hip prostheses were studied prospectively with plain radiography, aspiration and arthrography, Tc-99m phosphate bone imaging, and gallium imaging to evaluate loosening, infection, or both and to compare the accuracy of these modalities. Fifteen prostheses were revised yielding 14 loose femoral and eight loose acetabular components. Five proved to have infected prostheses. Arthrograms, plain radiographs, and bone scans are highly sensitive in detecting loosening of the femoral component. This study confirmed a previous retrospective study in demonstrating that accuracy of diagnosis of an abnormal acetabular component using all four modalities is less than that for the femoral component. In infected prostheses, phosphate bone imaging showed high sensitivity of a pattern that accurately diagnosed all the infected cases, whereas gallium imaging missed one case.     

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.     

Osteochondritis dissecans: analysis of mechanical stability with radiography, scintigraphy, and MR imaging

Twenty-one joints with stable (n = 9) or loose (n = 12) osteochondritis dissecans (OCD) lesions were examined in 15 subjects with plain radiography, three-phase bone scintigraphy, and magnetic resonance (MR) imaging. The lesion size and the thickness of the sclerotic margin as measured on plain radiographs were good parameters for predicting loosening. However, bone scintigraphy was more sensitive and specific in determining the mechanical stability of OCD lesions. MR imaging permitted direct visualization of loosening and fragment displacement; the latter permits differentiation of in situ loosening from a grossly unstable lesion. The noninvasive nature of bone scintigraphy and MR imaging makes them potentially preferable diagnostic modalities to arthrography for evaluating the mechanical status of OCD lesions.     

Plain film and arthrographic findings in painful total hip arthroplasties with surgical correlation

The plain films and arthrograms performed on 42 painful cemented hip arthroplasties in 40 patients were reviewed and the radiological findings compared to the surgical assessment of component stability. All radiography, which included Judet views in the plain films, was reviewed without knowledge of the surgical findings and without comparison with previous studies. Criteria for the detection of loosening of cemented femoral and acetabular components were predetermined. The accuracy of plain film assessment of acetabular component stability was increased significantly (p less than 0.05) by including oblique views in the plain film assessment. The accuracy of assessment of acetabular component stability on plain films was 88%, on arthrography 90% and, with both studies combined, was 98%. Femoral component stability was assessed accurately on 90% of plain films and 90% of arthrograms, and this was not improved by combining the studies. The difficulty of detecting low grade infections is discussed with results of pseudocapsule aspiration.     

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.     

Contrast and nuclear arthrography in loosening of the uncemented hip prosthesis

The recent popularity of ingrowth or uncemented hip arthroplasties has presented problems in the radiographic diagnosis of loosening because there is no longer a cement interface in which lucencies may be seen. We evaluated a combination of positive contrast and nuclear arthrography to see whether these studies could accurately detect loosening of uncemented femoral components of hip prostheses. We performed routine contrast and nuclear arthrography in 21 patients with ingrowth total hip arthroplasties or bipolar endoprostheses. The results were surgically confirmed in 12 patients. The contrast arthrogram was true positive in 5 and false negative in 5. There were no false positives and 2 true negatives. The nuclear arthrogram was true positive in 7 patients, false negative in 3, and true negative in 2. Taken together, there was only 1 patient in whom both contrast and nuclear arthrography were false negative, and there were no false positives. Thus, when either contrast or nuclear arthrography is positive, the sensitivity of the combined procedures is 90%; when both studies are negative, the specificity is 100%. The combination of contrast and nuclear arthrography is an accurate method of determining loosening of the femoral component of an uncemented hip arthroplasty or bipolar endoprosthesis in the patient with postoperative hip pain.     

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.     

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.     

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     

In-111-labeled leukocyte scintigraphy in suspected orthopedic prosthesis infection: comparison with other imaging modalities

When infection of prosthetic orthopedic implants is suspected, optimal management requires accurate confirmation or exclusion of infection. The authors retrospectively studied 98 patients with possible infection who underwent scanning with indium-111-labeled white blood cells (WBCs) and subsequently underwent surgery within 14 days. At surgery, 50 patients had infections, as determined by means of culture or histologic results. The diagnostic accuracy of In-111 scanning was compared with that of plain radiography, arthrography, three-phase bone scanning, and various clinical and laboratory findings classically associated with infection. Positive findings on In-111 WBC scans and elevated erythrocyte sedimentation rates were found to be the most predictive variables in the diagnosis of septic prostheses (P less than or equal to .001 and P less than or equal to .002, respectively). Likelihood ratio analysis more clearly demonstrated the superiority of In-111 WBC scanning, with positive and negative scans yielding likelihood ratios of 5.0 and 0.16, respectively.     

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.     

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.     

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.     

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%.     

Evaluation of the postoperative meniscus of the knee: a study comparing conventional arthrography, conventional MR imaging, MR arthrography with iodinated contrast material, and MR arthrography with gadolinium-based contrast material

Objective. To compare four imaging methods in the evaluation of the postoperative meniscus: conventional arthrography, conventional MR imaging, MR arthrography with iodinated contrast material, and MR arthrography with gadolinium-based contrast material. Design and patients. Thirty-three patients referred for knee MR examinations with a history of meniscal surgery were studied prospectively. At the first patient visit, conventional MR examination was followed by an MR arthrogram with gadolinium-based contrast material. At the second visit, a conventional arthrogram with iodinated contrast material was followed immediately by an MR examination. Imaging examinations were interpreted by a masked reader, and then compared with the results of repeat arthroscopic surgery in 12 patients. Results. The correct evaluation of the status of postoperative menisci was allowed in 12 of 13 patients (92%) by MR arthrography using gadolinium-based contrast agent, 10 of 13 patients (77%) by conventional MR examination, 9 of 12 patients (75%) by MR arthrography, and 7 of 12 patients (58%) by conventional arthrography. Conclusion. Intra-articular fluid is advantageous in the evaluation of patients with a suspected meniscal retear. MR arthrography with gadolinium-based contrast material is the most accurate imaging method for the diagnosis of meniscal retears. Received: 7 April 1999 Revision requested: 26 May 1999 Revision received: 17 June 1999 Accepted: 18 June 1999     

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.     

Review of three magnetic resonance arthrography related infections

We report three cases of intra-articular infection which followed injection for magnetic resonance arthrography. In an effort to reduce the risk of arthrogram related infection, representatives from radiology, infectious disease medicine, and microbiology departments convened to analyze the contributing factors. The proposed source was oral contamination from barium swallow studies which preceded the arthrogram injections in the same room. We propose safety measures to reduce incidence of arthrogram related infections.     

Arthrographic proof of loosening of the acetabulum following total endoprosthesis of the hip joint (author's transl)]

Arthrography is a useful method to prove the loosening of the cup after total hip replacement. Contrast medium seeping between the bone and acrylic is an unequivocal sign of loosening. False positive diagnoses are unknown. Because of the risk of infection, arthrography is only indicated, if plain films and push-pull-roentgenograms are not significant. Possible errors and complications are discussed.     

Elbow arthrography: a reassessment of the technique

Twenty-six elbow arthrograms were retrospectively reviewed. Each arthrogram consisted of conventional radiography, conventional tomography, standard double-contrast arthrography, and arthrotomography. Each of these four components was independently interpreted in a blinded fashion by six radiologists, each working alone. The four components were evaluated for presence or absence of intraarticular bodies, cartilage loss, or fractures. The results showed that conventional tomography was the most accurate single study. Arthrotomography rarely improved the diagnostic accuracy of noncontrast methods. It was useful in those few patients where detection of purely cartilaginous bodies, precise position of mineralized densities, or status of articular cartilage was desired. It may be possible to reduce the number of elbow arthrograms, thereby reducing time, cost, and radiation dose factors.     

K-edge digital subtraction arthrography of the painful hip prosthesis: a feasibility study

K-edge energy subtraction radiography is a method for detecting the presence of iodinated contrast material by subtracting two digital radiographs produced by X-ray beams with energies above and below the iodine K edge. We performed a feasibility study on the application of K-edge energy digital subtraction arthrography (KEDSA) to painful hip prostheses. During arthrography, loosening of the prosthesis is implied if contrast material is seen dissecting around the prosthesis, an often difficult detection task because of adjacent prosthesis metal or cement. In conventional arthrography a preliminary mask image is thus used from which films obtained after injection of iodinated contrast material are subtracted. Movement by the patient during this process may preclude subsequent subtraction. With KEDSA, since multiple image pairs may be obtained after the injection of contrast material, the problem of patient motion is virtually eliminated. A conventional X-ray tube operating between 55 and 65 kVp was alternately filtered by iodine and cerium filters to produce the KEDSA images. The apparatus was capable of producing a subtracted image within 3 sec. The technique was applied to phantoms and to six patients immediately after hip arthrography that had been positive for prosthesis loosening. Although of lower spatial resolution, the KEDSA images were, in all cases, positive for loosening in a pattern consistent with the conventional arthrographic images. KEDSA was shown to be successful in detecting extraarticular contrast material. During a single study, subtraction in various imaging planes as well as postexercise subtraction imaging can be accomplished-techniques not heretofore possible in routine subtraction arthrography.