Total ankle arthroplasty: a radiographic outcome study.

OBJECTIVE: Total ankle arthroplasty (TAA) is becoming a popular alternative to arthrodesis for patients with end-stage ankle arthrosis. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TAA and to correlate it with clinical outcome. MATERIALS AND METHODS: In a 9-year retrospective review of patients with TAA, all available ankle radiographs and clinical data were reviewed. Data analysis included descriptive statistics, Fisher exact test, and Kaplan-Meier survival curves for radiographic and clinical survival. RESULTS: Two hundred sixty-two TAAs in 260 patients were reviewed; 55% were in women, and the mean patient age was 61.5 years. The mean radiographic follow-up was 142 weeks, with an average of six radiographs per patient. One hundred sixty-three patients (62.2% of TAAs) developed one or more radiographic complications, including periprosthetic lucency (34.0%), hardware subsidence (24.4%), perihardware fracture (11.1%), syndesmotic screw loosening (10.3%), and screw fracture (6.5%). One hundred nineteen patients (45.4% of TAAs) developed symptoms of ankle pain or instability, and 71 patients (27.1% of TAAs) underwent at least one reoperation. In patients with radiographic complications, 41.7% developed ankle pain and 5.1% developed ankle instability, compared with 23.7% and 2.2%, respectively, of patients with no radiologic complications (p < 0.05). Of the patients with radiographic complications, 33.1% had at least one additional surgery compared with 17.1% of patients without radiographic complications (p < 0.05). CONCLUSION: Radiographic complications are common in patients after total ankle arthroplasty. There is a strong positive association between postoperative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist.

Allergic reactions to iodinated contrast media: premedication considerations for patients at risk.

The objectives of this article are to review allergy-type reactions to iodinated contrast media and the protocols utilized to prevent or reduce the occurrence of these adverse reactions in high-risk patients. We will begin by discussing the types or classifications of the adverse reactions to iodinated contrast media. We will then discuss reaction mechanisms, identify the patients at highest risk for adverse reactions, and clarify common misperceptions about the risk. Finally, we will discuss the actions of the medications used to help reduce or prevent allergy-type reactions to iodinated contrast media, the protocols used to help reduce or prevent contrast reactions in high-risk patients, and the potential side effects of these medications. We will also discuss the high-risk patient who has received premedication due to a prior index reaction and discuss the risk of having a subsequent reaction, termed "breakthrough reaction." Identifying patient at high risk for an "allergy-type" reaction to contrast media is an essential task of the radiologist. Prevention of or reduction of the risk of an adverse reaction is critical to patient safety. If an examination can be performed without contrast in a patient at high risk for an allergy-type reaction, it may be appropriate to avoid contrast. However, there are situations where contrast media is necessary, and the radiologist plays a vital role in preventing or mitigating an allergy-type reaction.

Radial head arthroplasty: a radiologic outcome study.

OBJECTIVE: The purpose of this study is to provide a radiographic outcome assessment of radial head arthroplasty in correlation with clinical outcomes and to determine whether there is an association between certain patient factors and clinical and radiographic outcomes. MATERIALS AND METHODS: A 10-year retrospective review was performed to identify patients with metal radial head arthroplasty. At least two follow-up radiographs were reviewed for each patient and were correlated with clinical information. Statistical analysis included calculation of complication rates, phi coefficient for variable association with complications, and Kaplan-Meier survival. RESULTS: A total of 258 radial head implants in 244 patients were reviewed. The mean patient age was 46 years, with mean follow-up time of 12.8 months. Two hundred nineteen (84.9%) implants were unipolar in design, whereas 39 implants were bipolar. The most common indication for arthroplasty was trauma (94% acute and 2% failed internal fixation). Radiographic abnormalities included nonbridging heterotopic ossification (38.0%), secondary radiocapitellar joint osteoarthritis (27.9%), loosening (19.8%), bridging heterotopic ossification (8.9%), fracture (2.3%), and hardware dislocation (2.7%). Overall, there were 62 second surgeries for either revision or removal. Reasons for second surgery included heterotopic ossification (53.2%), synovectomy or capsulectomy (43.5%), and infection (3.2%). There was a statistically significant association between radiographic complications and the presence of patient symptoms (p < 0.05). There was no association between radiographic or clinical complications with age, sex, side, or type of arthroplasty (R < 0.001). CONCLUSION: There is a positive association between radiographic findings and patient symptoms for postoperative complications after radial head arthroplasty. By 9 months, 50% of implants showed radiographic complications.

Current concepts of shoulder arthroplasty for radiologists: Part 1--Epidemiology, history, preoperative imaging, and hemiarthroplasty.

OBJECTIVE: The purpose of this article is to provide a review of indications for shoulder arthroplasty, describe preoperative imaging assessment, present new and modified designs of shoulder arthroplasty, illustrate normal and abnormal postoperative imaging findings, and review key radiographic measurements. CONCLUSION: Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing shoulder prostheses.

Current concepts of shoulder arthroplasty for radiologists: Part 2--Anatomic and reverse total shoulder replacement and nonprosthetic resurfacing.

OBJECTIVE: The purpose of this article is to provide a review of the indications for shoulder arthroplasty, describe preoperative imaging assessment, present new and modified designs of shoulder arthroplasty, illustrate normal and abnormal postoperative imaging findings, and review key radiographic measurements. CONCLUSION: Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing shoulder prostheses.

Radiologic review of total elbow, radial head, and capitellar resurfacing arthroplasty.

The use of metal and pyrolytic carbon radial head implants, capitellar resurfacing, and total elbow arthroplasty has become common in contemporary orthopedic surgery practice. The goal of total elbow arthroplasty is to decrease pain and restore an acceptable range of motion to the elbow joint. Rheumatoid arthritis is the primary indication for total elbow arthroplasty; newer indications include primary or posttraumatic osteoarthritis, fracture nonunion, acute comminuted fractures of the elbow, and postoperative resection of a neoplasm. Unlike total elbow arthroplasty, radial head replacement is most commonly performed in patients with trauma. Radial head fractures account for 33% of all elbow fractures in adults and are often associated with ligament disruption and valgus instability at the elbow. The goals of capitellar resurfacing arthroplasty include prevention of secondary osteoarthritis of the radiocapitellar joint and erosion in patients with radial head arthroplasty. Effective postoperative radiologic assessment of these different types of elbow reconstructions requires an understanding of their basic component design, physiologic purpose, and normal postoperative appearance, as well as the appearance of complications. Radiologists may have little training and experience with these new orthopedic devices.

Imaging features of superficial and deep fibromatoses in the adult population.

The fibromatoses are a group of benign fibroblastic proliferations that vary from benign to intermediate in biological behavior. This article will discuss imaging characteristics and patient demographics of the adult type superficial (fascial) and deep (musculoaponeurotic) fibromatoses. The imaging appearance of these lesions can be characteristic (particularly when using magnetic resonance imaging). Palmar fibromatosis demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis and extending along the subcutaneous tissues of the finger in parallel to the flexor tendons. T1 and T2-weighted signal intensity can vary from low (higher collagen) to intermediate (higher cellularity), similar to the other fibromatoses. Plantar fibromatosis manifests as superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. Linear tails of extension ("fascial tail sign") along the aponeurosis are frequent. Extraabdominal and abdominal wall fibromatosis often appear as a heterogeneous lesion with low signal intensity bands on all pulse sequences and linear fascial extensions ("fascial tail" sign) with MR imaging. Mesenteric fibromatosis usually demonstrates a soft tissue density on CT with radiating strands projecting into the adjacent mesenteric fat. When imaging is combined with patient demographics, a diagnosis can frequently be obtained.

Arthroplasty of the hand: radiographic outcomes of pyrolytic carbon proximal interphalangeal and metacarpophalangeal joint replacements.

OBJECTIVE: The purpose of this study was to describe the radiographic outcomes of pyrolytic carbon implants in the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints, determine the most common complications, and assess risk factors associated with complications. MATERIALS AND METHODS: Retrospective review over a 10-year period was performed to identify patients with pyrolytic carbon implants of the PIP or MCP joint. All available radiographs were reviewed and correlated with clinical information. Statistical analysis included calculation of the complication rate, Phi coefficient for variable association with a complication, and Kaplan-Meier survival. RESULTS: Forty-seven implants in 43 patients were reviewed. There were 30 PIP and 17 MCP implants. The mean age of the patients was 56 years. The mean radiographic follow-up was 17.2 months (range, 1-82 months). The indication for arthroplasty included osteoarthritis (55.3%), trauma (27.7%), rheumatoid arthritis (12.8%), and benign neoplasm (4.26%). Fourteen second surgeries were performed: four for retrieval and 10 for revision. Radiographic abnormalities included subsidence (31.9%); loosening with dorsal or volar tilt of the stem (34.1%); loosening without tilt (6.38%); periprosthetic fracture (8.51%); and ulnar subluxation of joint (4.26%). There was no statistical association (r < 0.001) between 1 mm or less of symmetric lucency around the distal implant with future complications. The sensitivity of radiography for the clinical failure of the implant was 28.6% and specificity, 30.3%. CONCLUSION: Of the 47 pyrolytic carbon PIP and MCP implants, 14 (29.8%) required surgical revision or retrieval, mostly for extensor tendon contractures. Compared with the clinical survival of the implant, radiographic survival was poorer and did not correlate with clinical survival. Tilt of the proximal stem and subsidence were the more common radiographic complications.

New and improved orthopedic hardware for the 21st century: part 1, upper extremity.

OBJECTIVE: The purpose of this article is to provide a survey of new orthopedic products for use in the upper extremity. CONCLUSION: Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing new orthopedic devices.

New and improved orthopedic hardware for the 21st century: part 2, lower extremity and axial skeleton.

OBJECTIVE: The purpose of this article is to provide a survey of new orthopedic products for use in the lower extremity and axial skeleton. CONCLUSION: Knowledge of the physiologic purpose, orthopedic trends, imaging findings, and complications is important in assessing new orthopedic devices.

Prospective randomized comparison of standard didactic lecture versus high-fidelity simulation for radiology resident contrast reaction management training.

OBJECTIVE: The objective of our study was to assess whether high-fidelity simulation-based training is more effective than traditional didactic lecture to train radiology residents in the management of contrast reactions. SUBJECTS AND METHODS: This was a prospective study of 44 radiology residents randomized into a simulation group versus a lecture group. All residents attended a contrast reaction didactic lecture. Four months later, baseline knowledge was assessed with a written test, which we refer to as the "pretest." After the pretest, the 21 residents in the lecture group attended a repeat didactic lecture and the 23 residents in the simulation group underwent high-fidelity simulation-based training with five contrast reaction scenarios. Next, all residents took a second written test, which we refer to as the "posttest." Two months after the posttest, both groups took a third written test, which we refer to as the "delayed posttest," and underwent performance testing with a high-fidelity severe contrast reaction scenario graded on predefined critical actions. RESULTS: There was no statistically significant difference between the simulation and lecture group pretest, immediate posttest, or delayed posttest scores. The simulation group performed better than the lecture group on the severe contrast reaction simulation scenario (p = 0.001). The simulation group reported improved comfort in identifying and managing contrast reactions and administering medications after the simulation training (p ≤ 0.04) and was more comfortable than the control group (p = 0.03), which reported no change in comfort level after the repeat didactic lecture. CONCLUSION: When compared with didactic lecture, high-fidelity simulation-based training of contrast reaction management shows equal results on written test scores but improved performance during a high-fidelity severe contrast reaction simulation scenario.

Imaging assessment of the postoperative arthritic wrist.

Wrist arthritis is a common disease entity that can result in severe pain, swelling, and decreased wrist motion, leading to the impairment of daily activities and vocational functions. Nonsurgical treatment for wrist arthritis can improve function and provide pain relief in some cases. With disease progression, however, conservative therapy may become ineffective, and surgical treatment may be required. The three main surgical options for wrist arthritis are arthrodesis, carpectomy, and arthroplasty. Because of the high prevalence of wrist arthritis, radiologists will commonly encounter images that were obtained in patients who have undergone one or more of these surgical options. All three options are common in contemporary orthopedic practice and have evolved in recent years, making it imperative that radiologists understand current procedures and stay abreast of advances in techniques and hardware. In addition, familiarity with both normal and abnormal postoperative imaging findings can aid in the assessment of complications and early failure.

Intracardiac thrombus and pulmonary embolism with cavitation and pneumomediastinum in a patient with protein S deficiency.

We present a case of intracardiac thrombus with pulmonary embolism and pulmonary infarction in a patient with protein S deficiency. Secondary infection of the pulmonary infarction resulted in pneumomediastinum. Thrombus in an unusual location in a young patient without known predisposing conditions is a characteristic feature of a hereditary thrombophilic disorder. Cavitation within a lesion adjacent to the mediastinal pleura can result in pneumomediastinum.

Current status of residency training of allergic-like adverse events to contrast media.

RATIONALE AND OBJECTIVES: Acute allergic-like adverse reactions to contrast media are rare but life-threatening events. Residents may complete training without ever managing such an event. Surveys have shown practicing radiologists to incorrectly dose and administer medications for treatment. Thus, contrast education may be deficient or inconsistent. The purpose of this study was to assess the current status of contrast reaction education in US radiology residency programs and the methods used to test residents' knowledge. MATERIALS AND METHODS: A 10-question anonymous survey on residency education methods and testing pertaining to allergic-like adverse events to contrast media was distributed through the Association of Program Directors in Radiology to program directors of US diagnostic radiology residency programs. The past 4 years of the American College of Radiology in-service examination were reviewed to assess the number of contrast reaction questions. RESULTS: Fifty-one programs responded to the Association of Program Directors in Radiology survey. Forty-nine percent of programs train with one lecture per year, 29.4% train with two lectures, and 16% train with three or more lectures. Only 44% include role-playing training during the lectures. Eighteen percent of programs are incorporating simulation training. Fewer than 50% of programs formally test residents' knowledge, and there were no questions on the 2007 to 2010 American College of Radiology in-service examinations. CONCLUSIONS: Resident education for contrast reaction management is primarily performed with annual lectures. Only 18% of programs are using simulation training, and <50% are testing residents' knowledge or skills. These findings suggest that education may need revision to incorporate simulation or other means of psychomotor learning.

Running an online radiology teaching conference: why it's a great idea and how to do it successfully.

RATIONALE AND OBJECTIVES: At the authors' institutions, faculty members and trainees work at multiple sites scattered miles apart, making it difficult to physically attend weekly teaching conferences. As a possible solution, a weekly online musculoskeletal teaching conference was undertaken. This quickly grew to include multiple other sites around North America. The authors share their experiences to assist other radiologists in organizing similar educational conferences. MATERIALS AND METHODS: The conferences are run using the Citrix GoToMeeting online meeting system. It runs on multiple platforms, including Mac, PC, iPhone, iPad, and Android. Attendees use a wide variety of microphones, sound cards, powered speakers, and webcams. Most users have fast institutional Internet connections, though several attend via slower connections, such as 3G. RESULTS: The conference has run successfully for 2 years, with participants logging in from 24 different sites in 18 states, two Canadian provinces, and three countries. About 48 sessions are held each year, with 10 to 15 sites joining the conferences each week and about 10 to 15 cases seen each week. Most attendees are from university medical centers, though several private practice radiologists attend regularly. Screen-sharing quality is superb, with no discernible difference between local and remote slide quality. Audio quality is usually quite good, particularly for those using computer audio. Audio feedback is an occasional problem, but this issue is now more easily addressed. No single time is equally convenient for participants scattered among four to six time zones. However, some sites find the conferences sufficiently valuable to rearrange their afternoon procedure schedules to reduce conflicts with the conferences. The social aspect of visiting weekly with friends and colleagues from afar is highly valued, as are seeing the wide range of pathology from other institutions and the ability to confer with colleagues on difficult cases. The conferences have also spawned several collaborative educational projects, such as an online journal club, a published book of conference cases, and an online musculoskeletal hardware atlas. CONCLUSIONS: The weekly online musculoskeletal conference described in this report has matured over 2 years from a peculiar experiment to a very popular conference. Cases not seen locally provide enrichment, and attendees gain educational opportunities not otherwise available. Other radiology groups should be able to create and maintain similar conferences.

Verification bias: an under-recognized source of error in assessing the efficacy of MRI of the meniscii.

RATIONALE AND OBJECTIVES: The sensitivity and specificity of magnetic resonance imaging (MRI) for diagnosis of meniscal tears has been studied extensively, with tears usually verified by surgery. However, surgically unverified cases are often not considered in these studies, leading to verification bias, which can falsely increase the sensitivity and decrease the specificity estimates. Our study suggests that such bias may be very common in the meniscal MRI literature, and illustrates techniques to detect and correct for such bias. MATERIALS AND METHODS: PubMed was searched for articles estimating sensitivity and specificity of MRI for meniscal tears. These were assessed for verification bias, deemed potentially present if a study included any patients whose MRI findings were not surgically verified. Retrospective global sensitivity analysis (GSA) was performed when possible. RESULTS: Thirty-nine of the 314 studies retrieved from PubMed specifically dealt with meniscal tears. All 39 included unverified patients, and hence, potential verification bias. Only seven articles included sufficient information to perform GSA. Of these, one showed definite verification bias, two showed no bias, and four others showed bias within certain ranges of disease prevalence. Only 9 of 39 acknowledged the possibility of verification bias. CONCLUSION: Verification bias is underrecognized and potentially common in published estimates of the sensitivity and specificity of MRI for the diagnosis of meniscal tears. When possible, it should be avoided by proper study design. If unavoidable, it should be acknowledged. Investigators should tabulate unverified as well as verified data. Finally, verification bias should be estimated; if present, corrected estimates of sensitivity and specificity should be used. Our online web-based calculator makes this process relatively easy.

Human T-cell lymphotropic virus, type 1 (HTLV-1)-associated myelopathy: MR findings.

We present a case of human T-cell lymphotropic virus, type 1 (HTLV-1)-associated myelopathy, also known as tropical spastic paresis. While the literature has previously described the neuroradiological findings of spinal atrophy and hyperintense T2 lesions involving the cerebral white matter, little information is available about musculoskeletal imaging findings. Our patient demonstrated diffuse muscle atrophy of the thigh muscles, particularly the posteromedial groups. Our case supports HTLV-1-associated myelopathy as a disease of neurological etiology with resulting muscular denervation.

Postpartum symphysis pubis diastasis.

The pubic symphysis is a midline, nonsynovial joint that connects the right and left superior pubic rami. The interposed fibrocartilaginous disk is reinforced by a series of ligaments that attach to it. The joint allows very limited movement of approximately 0.5-1mm. Under hormonal stimulation during pregnancy, there is widening of the symphysis pubis and the sacroiliac joints. Diastasis wider than 15 mm is considered subdislocation and is generally associated with pain, swelling, and occasionally deformity. Most cases can be treated conservatively. However, internal or external surgical stabilization may occasionally be required.

Verification bias an underrecognized source of error in assessing the efficacy of medical imaging.

RATIONALE AND OBJECTIVES: Diagnostic tests are validated by comparison against a "gold standard" reference test. When the reference test is invasive or expensive, it may not be applied to all patients. This can result in biased estimates of the sensitivity and specificity of the diagnostic test. This type of bias is called "verification bias," and is a common problem in imaging research. The purpose of our study is to estimate the prevalence of verification bias in the recent radiology literature. MATERIALS AND METHODS: All issues of the American Journal of Roentgenology (AJR), Academic Radiology, Radiology, and European Journal of Radiology (EJR) between November 2006 and October 2009 were reviewed for original research articles mentioning sensitivity or specificity as endpoints. Articles were read to determine whether verification bias was present and searched for author recognition of verification bias in the design. RESULTS: During 3 years, these journals published 2969 original research articles. A total of 776 articles used sensitivity or specificity as an outcome. Of these, 211 articles demonstrated potential verification bias. The fraction of articles with potential bias was respectively 36.4%, 23.4%, 29.5%, and 13.4% for AJR, Academic Radiology, Radiology, and EJR. The total fraction of papers with potential bias in which the authors acknowledged this bias was 17.1%. CONCLUSION: Verification bias is a common and frequently unacknowledged source of error in efficacy studies of diagnostic imaging. Bias can often be eliminated by proper study design. When it cannot be eliminated, it should be estimated and acknowledged.

Primary chordoid meningioma of the lung.

We present a case of primary chordoid meningioma of the lung in a 21-year-old patient with Diamond-Blackfan anemia. The neoplasm was incidentally discovered as a new right upper lobe mass on admission chest radiograph. Computed tomography examination showed a round mass with peripheral nodular enhancement. Pathologic diagnosis was conclusive for the rare entity of chordoid meningioma. To our knowledge, this is the first case showing the radiographic features of an extraskeletal and extracranially located chordoid meningioma.