Epidemiology of cervical spine injury victims.

STUDY OBJECTIVE: We sought to characterize demographics and injury patterns among patients undergoing emergency department cervical spine radiography for blunt traumatic injury. METHODS: All patients with blunt trauma undergoing cervical spine radiography at 21 centers were enrolled in this prospective, observational study. Patients' date of birth, age, sex, and ethnicity were noted before cervical spine radiography. RESULTS: Demographic factors associated with cervical spine injury, present in 818 of 33,922 patients, included the following: age of 65 years or older (relative risk [RR] 2.09; 95% confidence interval [CI] 1.77 to 2.59); "other" ethnicity (RR 1.79, 95% CI 1.46 to 2.19); male sex (RR 1.72, 95% CI 1.48 to 2.00); and white ethnicity (RR 1.50, 95% CI 1.31 to 1.72). Hispanic ethnicity (RR 0.64, 95% CI 0.51 to 0.79), female sex (RR 0.58, 95% CI 0.50 to 0.67), black ethnicity (RR 0.55, 95% CI 0.45 to 0.66), and age of less than 18 years (RR 0.39, 95% CI 0.27 to 0.55) were associated with reduced risk of cervical spine injury. CONCLUSION: Among patients undergoing ED cervical spine radiography, cervical spine injury is more common among the elderly, male subjects, and patients of white or "other" ethnicity. Because cervical spine injury occurs in patients in all demographic categories, however, this information cannot be used to select individual patients who should or should not undergo imaging.

Distribution and patterns of blunt traumatic cervical spine injury.

STUDY OBJECTIVE: Previous studies of cervical spine injury involve individual institutions or special populations. There is currently little reliable information regarding natural cervical spine injury patterns after blunt trauma. This substudy of the National Emergency X-Radiography Utilization Study project was designed to accurately assess the prevalence, spectrum, and distribution of cervical spine injury after blunt trauma. METHODS: We prospectively enrolled all patients with blunt trauma undergoing cervical spine radiography at 21 diverse institutions. Injury status was determined by review of all radiographic studies obtained on each patient. For each individual injury, we recorded which specific films revealed the injury, the level and location of injury on each vertebra, and the age and sex of the patient. RESULTS: Of 34,069 enrolled patients with blunt trauma, 818 (2.4%) individuals had a total of 1,496 distinct cervical spine injuries to 1,285 different cervical spine structures. The second cervical vertebra was the most common level of injury (286 [24.0%] fractures, including 92 odontoid fractures), and 470 (39.3%) fractures occurred in the 2 lowest cervical vertebrae (C6 and C7). The vertebral body, injured in 235 patients, was the most frequent site of fracture. Nearly one third of all injuries (29.3%) were considered clinically insignificant. CONCLUSION: Cervical spine injuries occur in a small minority of patients with blunt trauma who undergo imaging. The atlantoaxial region is the most common site of injury, and the sixth and seventh vertebrae are involved in over one third of all injuries. Other spine levels are much more commonly involved than has previously been appreciated. A substantial minority of radiographically defined cervical spine injuries are of little clinical importance.

Injuries about the knee and tibial/fibular shafts.

Injuries to the knee and tibial/fibular shafts are extremely common, with knee injuries alone accounting for over 1.3 million emergency department visits yearly in the United States. Many of these injuries will present with straightforward radiographic findings, but others will have a subtle or complex appearance. This article reviews injuries of the knee and proximal tibial/fibular shaft with emphasis on normal anatomic features that, when disrupted, indicate the presence of subtle but important bone or soft tissue trauma. Although the emphasis is on plain radiography, magnetic resonance (MR) and computed tomographic (CT) findings are discussed where appropriate.

Do radiologists use the American College of Radiology Musculoskeletal Appropriateness Criteria?

OBJECTIVE: The objective of this study was to determine the proportion of radiologists in three different radiology organizations who report using the American College of Radiology (ACR) musculoskeletal appropriateness criteria. MATERIALS AND METHODS: Radiologists from the Society of Skeletal Radiology, Georgia Radiological Society, and Utah Radiological Society were surveyed regarding their use of the ACR musculoskeletal appropriateness criteria. The surveys were carried out during 1998 and data were collected using written survey forms, telephone, and fax. RESULTS: The overall survey response rate was 298 (64%) of 465. Overall, 30% of respondents reported using the musculoskeletal appropriateness criteria. The proportion of respondents who used the musculoskeletal criteria was not different across the three organizations or for private practice compared with academic radiologists. CONCLUSION: The proportion of radiologists who report using the ACR musculoskeletal radiology appropriateness criteria is low. This result is consistent with other reports in the literature that show little impact on the practice of physicians after the distribution of written practice guidelines.

External validation of the Ottawa knee rules in an urban trauma center in the United States.

OBJECTIVE: We evaluated the Ottawa knee rules in a high-volume teaching hospital in the United States to determine whether the rules could be safely used to decide whether patients with acute blunt knee trauma should undergo radiography. SUBJECTS AND METHODS: During a 13-month period, 378 patients with acute blunt knee trauma were prospectively examined using the Ottawa knee rules. Data collected included the presence or absence of fracture predictors and the results of radiography. RESULTS: A fracture was seen in 43 (11%) of the 378 patients who met inclusion criteria. The knee rules predicted 42 of the 43 fractures; sensitivity was 98%, and specificity was 19%. Radiography of 65 patients (17%) who had no predictors for fracture could have been avoided if the knee rules had been used to screen for radiography. CONCLUSION: The Ottawa knee rules are highly sensitive for fracture in this setting and may safely be used to decide whether patients with acute blunt knee trauma should undergo radiography.

Accuracy of direct signs of tears of the anterior cruciate ligament.

OBJECTIVE: To evaluate the accuracy of direct magnetic resonance imaging (MRI) signs of tears of the anterior cruciate ligament. PATIENTS AND METHODS: Over the period April 1991 to February 1994, 92 consecutive MRI studies of the knee were obtained for which arthroscopic data were also available. The MRI studies were retrospectively evaluated for course, continuity, signal intensity, morphologic features, contour and visualization of the anterior cruciate ligament. Arthroscopic findings were correlated with individual primary signs and the overall MRI diagnosis. RESULTS: Among the cases studied were 4 partial and 32 complete tears of the anterior cruciate ligament (as determined by arthroscopy). Because of the low number of partial tears, it was not possible to draw any meaningful conclusions about the MRI diagnosis of this type of tear. For complete tears, the criteria with the highest accuracy were abnormal course of the ligament (96.0%) and high signal intensity (89.3%). The overall diagnostic accuracy of MRI was 98.8%. CONCLUSIONS: The most accurate direct MRI finding in patients with a complete tear of the anterior cruciate ligament was abnormal course of the ligament, followed by abnormally high signal intensity.

Discovery method and stage of breast cancer in two different patient populations.

Our purpose was to determine the discovery method and stage of newly discovered breast cancers at two different medical centers. To do this, we conducted a retrospective chart review at our urban and suburban teaching hospitals during 1991 through 1992 and 1992, respectively. Only 29 (26%) of 112 cancers at our urban hospital were discovered mammographically; 38 (38%) of 100 neoplasms were discovered using mammography at our suburban hospital. At both institutions, the mammographically discovered cancers had a lower stage than those detected clinically. Despite proven benefits and the efforts of organizations such as the American College of Radiology and the American Cancer Society, screening mammography remains underused in the patient populations that we studied.

Osteonecrosis associated with HIV infection.

OBJECTIVE: To report cases of osteonecrosis in patients who were HIV positive but had no apparent risk factors for osteonecrosis. PATIENTS AND METHODS: A computer search of records from two university-affiliated teaching hospitals yielded eight cases of osteonecrosis in HIV-positive patients and patients with AIDS. The patients' charts and radiographic records were reviewed to determine possible risk factors for osteonecrosis. RESULTS: In four of the eight patients no definite risk factors for osteonecrosis could be found. CONCLUSION: Osteonecrosis may be a musculoskeletal complication of HIV infection.

Renal osteodystrophy: imaging findings that mimic those of other diseases.

Musculoskeletal complications in patients with chronic renal failure are common and may be related to the disease itself or to treatment. The altered metabolism in patients with chronic renal failure leads to renal osteodystrophy, which consists of osteomalacia and secondary hyperparathyroidism [1]. Erosive changes attributable to secondary hyperparathyroidism may be easily confused with rheumatoid arthritis, seronegative spondyloarthropathies, infection, or even malignancy. Brown tumors and amyloid deposition can easily be mistaken for a neoplastic process. The purpose of this article is to illustrate radiographic findings that are caused by renal failure and that often mimic other diseases by use of plain radiographs, CT scans, and MR images. Particular emphasis is placed on periarticular findings.

Hip arthroplasty: the role of plain radiographs in outpatient management.

PURPOSE: To determine whether findings on plain radiographs alter clinical care in outpatient management after hip arthroplasty. MATERIALS AND METHODS: From June 1, 1993, through February 28, 1994, one arthroplasty surgeon saw 148 outpatients (age range, 15-86 years) after hip arthroplasty (163 prostheses). The surgeon made decisions about clinical management before he reviewed the plain hip radiographs. After he reviewed the radiographs, he recorded any changes in the management plan. RESULTS: In only one case did the radiographic findings change patient treatment. The prosthesis in this relatively asymptomatic patient had been in place for over 9 years and appeared clinically to be functioning well, but radiographs demonstrated aggressive granulomatosis. Therefore, the patient underwent revision arthroplasty. In the remaining 147 patients, radiographic findings had no impact on clinical management. CONCLUSION: Radiographic evaluation may be most beneficial in patients with hip prostheses that have been in place for many years to rule out asymptomatic bone loss due to aggressive granulomatosis.

Appearance of septic hip prostheses on plain radiographs.

OBJECTIVE: The purpose of this study was to evaluate the spectrum of plain radiographic findings in patients with septic hip prostheses. MATERIALS AND METHODS: Radiographs of 20 confirmed infected hip prostheses were examined for the presence or absence of lucency, type of lucency (focal or nonfocal), rapidity of radiographic change, periostitis, subsidence, and cement fracture. RESULTS: Findings were normal in 10 prostheses, but nonfocal lucencies mimicking mechanical loosening were seen in four cases. Two cases showed focal bone loss, indistinguishable from aggressive granulomatosis. A variety of findings, including subsidence and periostitis, were seen in the remaining four prostheses. CONCLUSION: Plain radiographs of septic hip prostheses often show normal findings but can show focal bone loss that mimics aggressive granulomatosis.

Aggressive granulomatosis complicating knee arthroplasty.

Aggressive granulomatosis is a potentially devastating complication of joint-replacement surgery. This condition likely represents a foreign body reaction to particulate metal, methylmethacrylate or polyethylene. The authors describe a 51-year-old woman in whom aggressive granulomatosis developed after total knee arthroplasty. Plain radiographs over a 3-year period showed progressively expanding focal areas of bone loss. Revision arthroplasty was necessary to prevent pathologic fracture.

Complications of hip arthroplasty causing periprosthetic radiolucency on plain radiographs.

The technique of hip arthroplasty is at least 30 years old and currently is performed 120,000 times per year in the United States [1]. Changes in materials and surgical techniques have markedly decreased the prevalence of infection and aseptic loosening. At the same time, other complications such as stress shielding and aggressive granulomatosis have become increasingly important complications of joint replacement [2]. All four of these entities manifest radiographically as periprosthetic lucency (Fig. 1.). The purpose of this essay is to illustrate the plain film findings of each of these complications.

Hip aspiration: a cost-effective and accurate method of evaluating the potentially infected hip prosthesis.

PURPOSE: The accuracy of fluoroscopy-guided hip aspiration in the diagnosis of infection in hip prostheses was evaluated. MATERIALS AND METHODS: Results from 147 preoperative aspiration cultures were compared with results of operative cultures. The relative costs of aspiration and nuclear medicine studies were also compared. RESULTS: With the operative culture results as the standard, sensitivity of hip aspiration was 92.8% and specificity was 91.7%. The negative and positive predictive values were 99.2% and 54.2%, respectively. Aspiration arthrography costs approximately 20% as much as complementary technetium sulfur colloid-indium-111 granulocyte scans, the most accurate nuclear medicine study used to evaluate potentially infected hip prostheses. CONCLUSION: Hip aspiration is an accurate and cost-effective method of evaluating the potentially infected hip prosthesis.

Pitfall in the diagnosis of nuchal cystic hygroma.

We present a case of spontaneous resolution of a nuchal cystic hygroma in a fetus with a normal karyotype. This unusual case is important in the counseling of patients with affected fetuses, since the transitory nature of the disease is not well known.