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.     

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.     

Comparison of 3.0-T MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population

Objective:

We report our experience in diagnostic sensitivity of 3.0-T conventional MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population.

Methods:

43 consecutive patients had both conventional hip MR and MR arthrography examinations performed. These examinations were reviewed retrospectively by independent reading of two musculoskeletal radiologists who read the MR and MR arthrogram examinations in a randomized fashion (i.e. MR and MR arthrogram examinations were read at separate sittings and in a randomized fashion so as not to bias reviewers). Scans were assessed for acetabular labral tears and chondral defects. All patients went on to arthroscopy.

Results:

Of these 43 patients, 40 had acetabular labral tears read by Reader 1 and 39 had acetabular labral tears read by Reader 2 on MR arthrogram, 39 had acetabular labral tears read by Reader 1 and 38 had acetabular labral tears read by Reader 2 on conventional MR examination. There were 42 labral tears in 43 patients at arthroscopy. There were four false-negative labral tears compared with arthroscopy on MR and three false negatives on MR arthrography for Reader 1 and five false negatives on MR and four false negatives on MR arthrography for Reader 2. Each reader had one false-positive labral tear compared with arthroscopy on both MR and MR arthrography. There were 32 acetabular chondral defects at arthroscopy. Reader 1 saw 21 acetabular chondral defects on conventional MR and 27 chondral defects at MR arthrography. Reader 2 saw 19 acetabular chondral defects at conventional MR and 25 acetabular chondral defects on MR arthrography. There were no false-positive readings of chondral defects compared with arthroscopy on MR and one false positive for Reader 1 and two false positives for Reader 2 on MR arthrography as compared with arthroscopy. On conventional MR examination, sensitivities and specificities as compared with arthroscopy were as follows: Reader 1 acetabular labral tear (90% sensitivity, 0% specificity) and Reader 2 acetabular labral tear (88% sensitivity, 0% sensitivity). On MR arthrogram, sensitivities and specificities as compared with arthroscopy for Reader 1 were 93%, 0% and for Reader 2 were 90%, 0%, respectively. Sensitivities and specificities for detection of acetabular chondral defects as compared with arthroscopy were Reader 1 conventional MR (65% sensitivity, 100% specificity), Reader 1 MR arthrography (81% sensitivity, 91% specificity), Reader 2 conventional MR (59% sensitivity, 100% specificity) and Reader 2 MR arthrography (71% sensitivity, 82% specificity).

Conclusion:

In this series, 3.0-T MR demonstrated sensitivity for detection of acetabular labral tears that rivals the sensitivity of 3.0-T MR arthrography of the hip. In this series, 3.0-T MR arthrography was more sensitive than conventional 3.0-T MR for detection of acetabular chondral defects.

Advances in knowledge:

3.0-T MR and MR arthrography are near equivalent in the diagnosis of acetabular labral tears. This information is useful for pre-operative planning.MR arthrography has been reported to be more sensitive and specific for detection of acetabular labral tears in the hip than conventional MRI.^1–10 MR arthrography has also been reported to be superior in detection of acetabular cartilage defects as compared with conventional MRI.¹¹ To our knowledge 3.0-T MR vs 3.0-T MR arthrography sensitivity for detection of acetabular labral tears and chondral defects has not been specifically assessed.To our knowledge, Petersilge et al¹ first reported the utility of hip MR arthrography in the diagnosis of acetabular labral tears. Toomayan et al² compared MR arthrography of the hip with conventional MRI of the hip in different patient populations. He found MR arthrography with a small field of view to be substantially more sensitive for detection of acetabular labral tears than conventional MRI. Sutter et al¹¹ found 1.5 T MR arthrography to be superior to conventional MRI for detecting labral tears and acetabular cartilage defects.Patients with acetabular labral tears present with symptoms of persistent pain, clicking, locking and decreased range of motion. With the availability of hip arthroscopy, labral tears can more easily be addressed with minimally invasive surgery. Accurate pre-operative identification of labral tears is needed.² Based on previous studies demonstrating the accuracy of MR arthrography in detection of acetabular labral tears, surgeons often request MR arthrography of the hip to characterize labral tears prior to surgery.^1–10 The purpose of this study is to assess 3.0-T MR vs MR arthrography diagnostic performance in detection of acetabular labral tears and chondral defects in the same patient population using arthroscopy as a reference standard.     

Comparison of MR arthrography with arthroscopy of the hip for the assessment of intra-articular loose bodies

Objective To assess the specificity and sensitivity of MR arthrography of the hip in comparison with arthroscopy for the evaluation of intra-articular loose bodies. Design Over a 3-year period, 81 consecutive patients underwent a total of 82 hip arthroscopies by a single orthopedic surgeon for intractable hip pain. Of the 82 arthroscopies, 70 had pre-operative MR arthrograms. Of these, 57 were available for retrospective review, after which they were compared with the operative notes of the subsequent arthroscopies. Results Of 82 arthroscopies 16 (20%) demonstrated intra-articular loose bodies, while, in the study group, nine of 57 had loose bodies (16%). There was a total of seven discordant cases (five false negatives and two false positives). The sensitivity of MR arthrography for detection of intra-articular loose bodies was 44%, while the specificity was 96%. Conclusion While the specificity of MR arthrography for the detection of intra-articular loose bodies was high (96%), the sensitivity was not nearly as good (44%). Presented at the Special Scientific Section of the ISS in Vancouver, Canada, September 2006.     

Fat-suppressed 3D spoiled gradient-echo MRI and MDCT arthrography of articular cartilage in patients with hip dysplasia

OBJECTIVE: Our objective was to assess the diagnostic ability of MDCT arthrography for acetabular and femoral cartilage lesions in patients with hip dysplasia. MATERIALS AND METHODS: A disorder of the articular cartilage was evaluated in 20 hips of 18 patients with acetabular dysplasia who did not have osteoarthritis or who had early stage osteoarthritis before undergoing pelvic osteotomy surgery. The findings on fat-suppressed 3D fast spoiled gradient-echo MRI and MDCT arthrography of the hip were evaluated by two independent observers, and sensitivity, specificity, and accuracy were determined using arthroscopic findings as the standard of reference. Kappa values were calculated to quantify the level of interobserver agreement. RESULTS: The sensitivity and specificity for the detection of any cartilage disorder (grade 1 or higher) were (observer 1/observer 2) 49%/67% and 89%/76%, respectively, on MRI, and 67%/67% and 89%/82%, respectively, on CT arthrography. The sensitivity and specificity for the detection of cartilage lesions with substance loss (grade 2 or higher) were (observer 1/observer 2) 47%/53% and 92%/87%, respectively, on MRI, and 70%/79% and 93%/94%, respectively, on CT arthrography. CT arthrography provided significantly higher sensitivity in the detection of grade 2 or higher lesions than MRI for both observers. Interobserver agreement in the detection of grade 2 or higher cartilage lesions was moderate (kappa = 0.53) on MRI and substantial (kappa = 0.78) on CT. CONCLUSION: MDCT arthrography is a sensitive and reproducible method for assessing articular cartilage lesions with substance loss in patients with hip dysplasia.     

Arthrography of painful hips following arthroplasty: digital versus plain film subtraction

Digital and manual subtraction images obtained during the arthrographic evaluation of 78 painful hip prostheses were reviewed retrospectively. Revision arthroplasty was performed in 53 of these cases, and the arthrographic and surgical findings were correlated. The digital and manual subtraction images were evaluated without knowledge of the surgical results using established criteria for component loosening. Digital subtraction arthrography of the femoral component demonstrated a 96% sensitivity and 100% specificity for the diagnosis of component loosening. Sensitivity and specificity for acetabular component loosening were 83% and 80%, respectively. Plain film subtraction of the femoral component demonstrated a 79% sensitivity and 100% specificity; the sensitivity and specificity for the acetabular component were 75% and 80%, respectively. The difference between detection of femoral component loosening on digital as opposed to manual subtraction images was statistically significant (P<0.05). This study demonstrates that digital subtraction improves the evaluation of femoral component loosening in painful hip prostheses.     

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.     

The role of multidetector CT arthrography in the investigation of suspected intra-articular hip pathology

The aim of this study was to evaluate the role of multidetector CT (MDCT) arthrography in the diagnosis of intra-articular hip pathology. A retrospective review of 96 patients who had undergone CT hip arthrography was performed. Data regarding the presence of a labral tear, paralabral cyst, chondral loss, acetabular version, femoral morphology and fibrocystic change were collected. We detected 28 labral tears (24 anterior, 2 anterolateral, 1 lateral and 1 posterolateral). An abnormal labral-chondral transitional zone was seen in 9 patients and 4 patients had surface labral fraying. We identified three paralabral cysts. Acetabular cartilage loss was detected in 45 and femoral cartilage loss in 9 patients. An abnormal anterior femoral head and neck junction was present in 18 hips and fibrocystic change in 8. Acetabular retroversion was present in 11 hips. 63 sets of patient notes were reviewed, of which 49 were in-patients with abnormal MDCT arthrogram findings. Surgical correlation was available in 27 patients. There was a discrepancy between the findings of a labral tear in one patient (false negative, 90% sensitivity and 100% specificity) and the presence of acetabular cartilage loss (88% sensitivity and 100% specificity) and femoral cartilage loss (94% sensitivity and 100% specificity) in three patients. MDCT arthrography affords accurate detection of intra-articular hip pathology.The investigation of suspected intra-articular hip pathology is challenging. Arthroscopy represents the gold standard but is invasive, necessitates a general anaesthetic and is best reserved for patients in whom concomitant therapeutic intervention is to be undertaken. Much of the radiology literature has focused on the use of MR arthrography of the hip to detect labral and cartilage pathology [1–5]. A number of groups have also studied the role of non-contrast MRI in the detection of labral tears associated with femoroacetabular impingement and acetabular dysplasia [6–9]. Both non-contrast MRI and MR arthrography have limitations in terms of spatial resolution, which can make the detection of subtle labral and cartilage pathology challenging [4]. Modern spiral multidetector CT (MDCT) technology allows submillimetre spatial resolution and has revitalised interest in the role of CT arthrography in the wrist, shoulder, knee, elbow and ankle [10–17]. There are few published data on the utility of this technique in the investigation of intra-articular hip pathology. Several studies have investigated the ability of MDCT arthrography to assess cartilage loss in the hip and have demonstrated that its accuracy is equal to, or can outperform, MR arthrography [18–20]. There are limited reports regarding the ability of MDCT arthrography to assess labral pathology [9]. The aim of this study was to evaluate the role of MDCT arthrography in the diagnosis of intra-articular hip pathology in a consecutive group of patients.     

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.     

64-slice MDCT arthrography in shoulder instability: our experience

PURPOSE: This study was performed to assess the diagnostic accuracy of air-contrast 64-slice multidetector computed tomography (MDCT) arthrography in the evaluation of glenohumeral joint instability by comparison with conventional arthroscopy. MATERIALS AND METHODS: Fifty patients with a history of shoulder instability underwent MDCT arthrography with thin collimation scans. The raw data were transferred to a workstation and processed using multiplanar reformation (MPR) and volume rendering (VR) algorithms. All patients subsequently underwent conventional arthroscopy. The results of the two techniques were compared and their sensitivity and specificity calculated. RESULTS: We diagnosed eight anterosuperior labrum lesions (group 1), 32 anteroinferior labrum lesions (group 2) and two posterior labrum lesions (group 3). Overall sensitivity and specificity (groups 1, 2, 3) were 88% and 100%, respectively. In group 1, sensitivity was only 66% (four false negatives), whereas in groups 2 and 3, it was 94% (two false negatives) and 100%, respectively. The labrum lesions were also found to be associated, with 100% sensitivity and specificity, with 20 lax capsules, 17 Hill-Sachs lesions, five Bankart lesions, two Perthes lesions and three complete rotator-cuff tears. CONCLUSIONS: Air-contrast MDCT arthrography is fast, reproducible, well tolerated and very accurate in the evaluation of lesions causing shoulder instability.     

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%.     

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。     

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.     

3.0 T conventional hip MR and hip MR arthrography for the acetabular labral tears confirmed by arthroscopy

Objective

To evaluate the value of hip MR for diagnosing acetabular labrum tears, and to further compare the diagnostic performances of conventional MR with MR arthrography in acetabular labrum tears.

Methods

90 patients undergoing both hip MR examination and subsequent hip arthroscopy were retrospectively evaluated. Of these patients, 34 accepted both conventional MR and MR arthrography; while the other 56 only underwent conventional MR examination. All hip MR images were independently reviewed by two radiologists, and further compared with the results of hip arthroscopy.

Results

59 of 90 patients were confirmed with acetabular labral tears by hip arthroscopy and 31 without tears. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of conventional MR for evaluating the acetabular labral tears were 61.0%, 77.4%, 83.7% and 51.1% (radiologist A), and 66.1%, 74.2%, 82.9% and 53.4% (radiologist B), respectively, with good consistency between the two observers (K = 0.645). The sensitivity, specificity, PPV and NPV of MR arthrography for assessing the acetabular labral tears were 90.5%, 84.6%, 90.5% and 84.6% (radiologist A), and 95.2%, 84.6%, 90.9% and 91.7% (radiologist B), respectively, with excellent good consistency between the two observers (K = 0.810). The sensitivity and NPV of MR arthrography for diagnosing the acetabular labral tears were significantly higher than those of conventional MR (both P < 0.05).

Conclusion

Hip MR arthrography is a reliable evaluation modality for diagnosing the acetabular labral tears, and its diagnostic performance is superior to that of conventional MR at 3.0 T.     

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.     

Combined radionuclide and radiocontrast arthrography for evaluating hip arthroplasty

Twenty-two patients had combined radiographic and radiocolloid arthrography. The two procedures were in agreement in 86% of the patients as to whether the femoral component was loose or not. Fourteen patients has surgical revision of the prosthesis and in 3 (23%) radiographic arthrography was falsely negative. No false negative results were obtained with radiocolloid arthrography thus far. The radionuclide method cannot be used to assess the acetabular component.     

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.     

Ultrasound versus magnetic resonance arthrography in acetabular labral tear diagnostics: a prospective comparison in 20 dysplastic hips

Background: Acetabular labral tears are highly associated with hip dysplasia. Magnetic resonance arthrography (MR arthrography) is the expensive and time-consuming contemporary gold-standard method in the radiological assessment of acetabular labral tears.

Purpose: To assess the diagnostic ability of noninvasive ultrasound (US) examination compared to MR arthrography in diagnosing acetabular labral tears in dysplastic hip joints.

Material and Methods: The study compared US examination and MR arthrography diagnosis of labral tears in 20 consecutively referred dysplastic hip joints.

Results: The ability to diagnose acetabular labral tears upon US examination was calculated: sensitivity 44%, specificity 75%, positive predictive value 88%, and negative predictive value 25%.

Conclusion: The ability of US examination in diagnosing acetabular labral tears is not yet good enough. The technique is still to be developed, and more experience, especially with the interpretation of US examinations, is needed.     

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.     

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.