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.     

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%.     

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.     

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.     

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.     

Digital arthrography in the evaluation of painful joint prostheses

Digital arthrography was accomplished in 16 patients who had painful prostheses. In each instance, resulting arthrographic abnormalities were compared with those apparent on subsequent overhead radiographs. Results indicate the potential value of the digital technique in this clinical setting. The examination is easy to perform and rapid, and allows the examiner to view the changing images in the subtraction mode. Image manipulation and enhancement are also possible.     

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.     

Digital subtraction arthrography

The technology of digital subtraction image processing was applied as a substitute for conventional arthrographic subtraction techniques in the evaluation of 29 joints in 27 patients. There were 15 total hip replacements, one total knee replacement, eight wrists, three shoulders, and two ankles. Information regarding prosthetic component loosening and ligamentous disruption of carpal bone articulations could be determined with a high degree of accuracy when compared with information gained using conventional radiographic methods. Our results indicate that this method may be a suitable substitute for other arthrographic techniques.     

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.     

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.     

Surgical planning of total hip arthroplasty: accuracy of computer-assisted EndoMap software in predicting component size

Purpose The purpose of our study was to assess the accuracy of a computer-assisted templating in the surgical planning of patients undergoing total hip arthroplasty utilizing EndoMap software (Siemans AG, Medical Solutions, Erlangen, Germany). Endomap Software is an electronic program that uses DICOM images to analyze standard anteroposterior radiographs for determination of optimal prosthesis component size.Methods We retrospectively reviewed the preoperative radiographs of 36 patients undergoing uncomplicated primary total hip arthroplasty, utilizing EndoMap software, Version VA20. DICOM anteroposterior radiographs were analyzed using standard manufacturer supplied electronic templates to determine acetabular and femoral component sizes. No additional clinical information was reviewed. Acetabular and femoral component sizes were assessed by an orthopedic surgeon and two radiologists. Mean and estimated component size was compared with component size as documented in operative reports.Results The mean estimated acetabular component size was 53 mm (range 48–60 mm), 1 mm larger than the mean implanted size of 52 mm (range 48–62 mm). Thirty-one of 36 acetabular component sizes (86%) were accurate within one size. The mean calculated femoral component size was 4 (range 2–7), 1 size smaller than the actual mean component size of 5 (range 2–9). Twenty-six of 36 femoral component sizes (72%) were accurate within one size, and accurate within two sizes in all but four cases (94%).Conclusion EndoMap Software predicted femoral component size well, with 72% within one component size of that used, and 94% within two sizes. Acetabular component size was predicted slightly better with 86% within one component size and 94% within two component sizes.     

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.     

Arthrography after total hip arthroplasty: utility of postambulation radiographs

We compare pre-and postambulation arthrograms in 24 patients with total hip arthroplasty. In nearly half (42%) of these cases, the arthrographic evidence of a loosened prosthesis was more obvious after ambulation. Three patients (12.5%) had components which were normal by arthrographic criteria before walking, but were abnormal afterwards. We conclude that postambulation radiographs are valuable in patients who are examined for suspected loosening of prosthetic components.     

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.     

股骨侧骨水泥假体翻修术

目的 探讨非感染性股骨侧骨水泥假体翻修术的手术指征及手术技巧。方法 回顾性分析1998年1月－2001年12月接受股骨侧骨水泥假体翻修术患者45例，其中男19例，女26例；年龄59－67岁，平均64岁。翻修原因中，人工股骨头置换术后柄松动9例，髋臼磨损7例，全髋置换术后柄松动17例，柄断裂2例，髋臼松动或臼松动或臼柄松动10例。所有病例均I期翻修，采用骨水泥假体，有骨质缺损者同时植骨。结果 术后无一例发生伤口感染、脱位和神经血管并发症，术后6个月，患者可弃拐行走。随访6－40个月，平均23个月，患者髋关节功能良好，Harris评分由术前35．0分提高至术后88．5分。结论 假体松动是人工关节翻修术的主要原因。在翻修假体的选择上，骨水泥假体主要适用于老年骨质疏松患者、需长段异体骨复合人工假体患者、非骨水泥假体翻修失败患者及关节感染需在翻修术中使用抗生素骨水泥患者。翻修手术对手术技巧和手术设备要求较高，术前计划必不可少。     

Cemented total hip prosthesis: radiographic and scintigraphic evaluation

Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection.     

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 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.     

骨水泥股骨柄和非骨水泥臼杯在首次全髋关节置换术中的应用

目的 随访一组采用同一类型骨水泥型股骨假体和非骨水泥型髋臼假体组合在首次人工全髋关节置换术中的应用，并探讨该种混合型假体对于全身健康情况和骨质质量一般较差的老年患者的适用情况。方法 共有75例患者84髋得到临床和影像学随访，平均年龄为67．9岁。其中老龄股骨颈骨折患者41例41髋，平均年龄72．1岁。随访时间为4．1年。随访内容包括患者的健康状况、手术方法、术后恢复情况以及对于骨形态、骨水泥固定质量和假体稳定性的判断。结果 2例股骨假体发生无菌性松动，臼杯则未见骨溶解或松动征象。未出现骨水泥相关的术中或术后死亡，各类全身性疾病在围手术期无加重表现。41例股骨颈骨折患者术后Harris评分为81.1分。股骨近端骨形态A型17髋（20％），B型47髋（56％），C型20髋（24％）。骨水泥固定质量分别为A级31髋（37％），B级40髋（48％），C级13髋（15％）。结论 混合型人工关节置换术的短期随访结果良好；混合型人工关节的术后即时稳定性有利于老年患者的康复；在手术中必须应用现代骨水泥技术。     

SPECT/CT对全髋关节置换术后无菌性假体松动的诊断价值

目的探讨SPECT/CT对全髋关节置换术后无菌性假体松动的诊断价值。方法对临床疑似全髋关节置换术后假体松动的58例患者(69个髋关节),行SPECT/CT检查,观察分析其图像特征。最终结果由手术或5个月以上随访确诊。计算SPECT/CT显像对假体松动的诊断灵敏度、特异度和准确度。结果69个髋关节,临床最终确诊假体松动61个(髋臼松动17个,假体柄松动36个,髋臼及假体柄均松动8个)。SPECT/CT显像阳性64个(其中假阳性3个,余61个与手术结果一致);阴性5个,均为真阴性。SPECT/CT对假体松动的诊断灵敏度、特异度、准确度分别为100%(61/61)、62.50%(5/8)、95.65%(66/69)。结论SPECT/CT显像可灵敏、准确地诊断全髋关节置换术后无菌性假体松动的情况,值得临床推广。