Evaluation of the glenoid labrum with 3-T MRI: is intraarticular contrast necessary?

OBJECTIVE: The purpose of this study was to evaluate the diagnostic accuracy of 3-T MRI versus 3-T MR arthrography for assessing labral abnormalities in the shoulder using arthroscopy as the gold standard. SUBJECTS AND METHODS: Forty-two patients (28 men, 14 women; mean age, 33 years) underwent MR arthrography and conventional MRI of the same shoulder. Two patients underwent bilateral shoulder examinations, for a total of 44 shoulder examinations. Twenty-two shoulders underwent arthroscopy. The results of arthroscopy were used as the reference standard. Three musculoskeletal radiologists prospectively and independently interpreted MRI and MR arthrography examinations. Differences in performance of conventional MRI and MR arthrography were analyzed for statistical significance by the two-tailed McNemar test. RESULTS: Of the 22 arthroscopies performed, 26 labral tears were found in 18 shoulders and four shoulders were normal with respect to the labrum. There were 12 superior, nine posterior, and five anterior labral tears identified at arthroscopy. By consensus review, conventional MRI identified nine of 12 superior (sensitivity, 75%; specificity, 100%), seven of nine posterior (sensitivity, 78%; specificity, 92%), and three of five anterior (sensitivity, 60%; specificity, 94%) labral tears. MR arthrography identified nine of 12 superior (sensitivity, 75%; specificity, 100%), eight of nine posterior (sensitivity, 89%; specificity, 100%), and five of five anterior (sensitivity, 100%; specificity, 100%) labral tears. CONCLUSION: Although the power of our preliminary study is small, the results suggest that intraarticular contrast material is helpful in diagnosing labral tears in the shoulder, particularly tears of the anterior labrum. Our preliminary results suggest that MR arthrography adds value for diagnosing labral tears in the shoulder compared with conventional MRI even at 3 T.

Activity scale for arthroplasty patients after total hip arthroplasty.

The purpose of the Activity Scale for Arthroplasty Patients (ASAP) is to develop and validate a self-report questionnaire that demonstrated discrimination of functional gains, low burden, appropriate concurrent validity, and was not limited by ceiling effects. We identified 128 high-functioning hip arthroplasty patients from our database who completed a 25-item ASAP and Lower Extremity Functional Scale questionnaires and a set of anchor questions. Factor analysis identified 10 items associated with 2 distinct factors: (1) activities and (2) running and running-related environments. These 10 items were retained and were identified as the ASAP. The ASAP may be useful in high-level hip arthroplasty patients where other scales fail to capture activities secondary to ceiling effects. In addition, the scale burden is minimized by inclusion of only 10 items.

Relative purity of thrombin-based hemostatic agents used in surgery.

BACKGROUND: Hemostatic agents used in surgery contain thrombin isolated from either a bovine or human source. The use of thrombin derived from a bovine source has been associated with the development of an abnormal immune response, but a study of the immunoreactivity of the various commercially available thrombin preparations has not been conducted. This study determined the relative purity of commercially available thrombin preparations, if humans have natural antibodies that recognize these preparations, and if elicited antibodies against bovine thrombin cross-react with other bovine or human hemostatic agents. STUDY DESIGN: The purity of hemostatic agents was determined by protein and substrate assays, electrophoresis, and immunoblotting. The natural antigenicity and cross-reactivity of elicited antibodies were measured by ELISA using serum samples from 82 donors from the Red Cross and serum collected from patients exposed to bovine thrombin, respectively. RESULTS: All of the bovine thrombin preparations were found to contain the xenogeneic carbohydrate galactosealpha1-3galactose. The natural antigenicity of the bovine thrombin preparations was greater than that of a human thrombin preparation and similar to that of porcine aortic endothelial cells. Antibodies elicited against bovine thrombin were found to cross-react with other bovine preparations and other xenoantigens but not with human hemostatic preparations. CONCLUSIONS: All patients have antibovine thrombin antibodies, even before exposure to bovine thrombin-containing hemostatic agents. The cross-reactivity of elicited antibovine thrombin antibodies indicates that if a patient has been sensitized to a bovine product, it is likely safer to use a human-derived product in lieu of a bovine product.

Antihuman factor V antibodies after use of relatively pure bovine thrombin.

Although bovine thrombin is commonly used in the operating room, there is evidence that exposure to bovine thrombin can result in the development of autoimmune antibodies, usually against factor V, which can lead to a profound coagulopathy. It is thought that impurities in bovine thrombin preparations are responsible for the adverse reactions in patients. Here we describe a case in which exposure to a relatively pure bovine thrombin preparation resulted in the development of an antihuman factor V antibody-associated coagulopathy. This report calls into question the safety of even relatively pure bovine thrombin.