Superior labral anterior posterior (SLAP) lesions of the glenoid labrum: reliability and accuracy of MR arthrography for diagnosis.

PURPOSE: To determine the reliability and accuracy of magnetic resonance (MR) arthrography for the diagnosis of superior labral anterior posterior (SLAP) tears. MATERIALS AND METHODS: The MR arthrograms in 80 patients who underwent arthroscopy and MR arthrography during a 54-month period were retrospectively reviewed. MR arthrograms were independently scored by three observers for the presence and type of SLAP lesion. Type I SLAP lesions were regarded as negative as they most often are not clinically relevant. Interobserver agreement for detection of SLAP lesions was calculated by using kappa coefficients. The differences in areas under the receiver operating characteristic (ROC) curves were assessed with a univariate z score test. RESULTS: At arthroscopy, there were 25 SLAP tears: type II (n = 22), type III (n = 2), and type IV (n = 1). Sensitivity, specificity, and accuracy of each reader were 92%, 84%, and 86%; 92%, 82%, and 85%; and 84%, 69%, and 74%, respectively. Interobserver agreement for SLAP tears was substantial (kappa = 0.77) to moderate (kappa = 0.52, kappa = 0.44). The areas under the ROC curves for each reader were 0.94, 0.93, and 0.83, which were not significantly different. CONCLUSION: MR arthrography of the shoulder is reliable and accurate for detection of SLAP tears.

Ankle injuries in the pediatric population.

Ankle injuries occur with considerable frequency in the pediatric population, although diagnosis is rarely straightforward. In this paper, we highlight the more common pitfalls in diagnosis and management, calling upon classic and contemporary literature and our own combined 30-year experience in managing pediatric lower extremity problems.

Symptomatic interarticular migration of glenoid suture anchors.

SUMMARY: There have been numerous modifications of Bankart's initial description of glenoid labral repair to help simplify and facilitate this procedure. One of the more common devices used for this purpose has been the suture anchor. The authors report a case of interarticular migration of the suture anchor used for anterior capsular stabilization in the shoulder. Surgeons need to be aware of this potential complication, especially in patients who have had suture anchors placed and develop mechanical symptoms postoperatively.

The young athlete.

Youth sports are becoming increasingly popular in America. Previous studies have shown that children and adolescents are not small adults in their response to exercise and stress. Intensive competition and training may be associated with acute and chronic illness and injury. In addition, we comment on the injury risks that are generated by pressures to perform, injuries from urbanized non-team sports, and legislation underway to minimize these injuries. We also provide insight into psychological and sociological trends in the pediatric athlete and discuss the roles of the pediatrician, coach, trainer, and parent and the ways in which these roles impact upon injury and prevention in this population.

Analysis of two purified mutants of Escherichia coli aspartate transcarbamylase with single amino acid substitutions.

Two mutant versions of Escherichia coli aspartate transcarbamylase have been purified and analyzed kinetically. Each of these mutant enzymes contains a single amino acid different from the wild-type enzyme, which was introduced by suppression of a nonsense codon within the E. coli pyrB gene. These enzymes exhibited alterations in both homotropic and heterotropic interactions with little change in specific activity. Depending upon the site of the substitution, the allosteric interactions have been either enhanced or diminished over the wild-type enzyme. Carbamyl phosphate saturation curves indicate that aspartate and carbamyl phosphate homotropic co-operativity are separable. Experiments employing the allosteric effectors indicate that the transmission of the regulatory effect is dependent upon the structure of the catalytic subunit, and that CTP inhibition can be partially decoupled from ATP activation. The kinetics of one of the mutants is unusually sensitive to dissociation at elevated temperatures. This sensitivity may be due to weakened interactions between the subunits of the enzyme.