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Multidirectional instability is not clearly understood. Excessive capsular laxity has been proposed as the key component. However, because ligaments fail to resist humeral head translation until they are tensioned, glenohumeral instability in the mid range of motion cannot be explained by capsuloligamentous pathology alone. Capsulolabral augmentation is designed to increase glenohumeral stability by 2 separate mechanisms: deepening the glenoid concavity and reducing capsular laxity. This is accomplished by shifting the capsule to buttress the glenoid labrum. Hence, the glenolabral concavity in which the humeral head is stabilized by compression throughout the entire range is enhanced. The purposes of this study were to examine glenolabral depth and glenohumeral stability before and after labral augmentation and to measure the effect of diminished capsular laxity on motion in clinically important positions. We compared glenolabral depth, resistance to humeral head displacement, and glenohumeral range of motion before and after capsulolabral augmentation. Glenolabral depth was measured as the lateral displacement of the center of the humeral head translating from the glenoid fossa. We recorded a mean increase in glenoid depth of 1.9 mm inferiorly, 2.0 mm posteroinferiorly, and 0.9 mm posteriorly (P <.02). Resistance to humeral head displacement was measured by use of the stability ratio, defined as the translatory force required to displace the humeral head divided by the force compressing the humeral head into the glenoid fossa. The mean stability ratio was increased by 0.24 inferiorly and 0.24 posteroinferiorly (P <.02). Motion was measured by achieving 30° and 60° elevation in the 0°, 30°, 60°, and 90° planes of elevation and measuring the extent of possible internal rotation for each of these 8 positions when the capsule was tensioned to exert 1000 N-mm of torque. Reduction of internal rotation in these positions was a mean of 15° at 1000 N-mm of torque. This study demonstrates that humeral head stability within the glenolabral fossa is increased by local capsular augmentation. A simultaneous reduction in capsular laxity is achieved, which partially limits glenohumeral motion. Understanding the biomechanical effect of this procedure helps the physician to establish surgical goals and to explain to patients the rationale of why this procedure may be clinically efficacious. (J Shoulder Elbow Surg 2001;10:532-8.)

A total of 191 patients from 29 orthopedic practices are analyzed in this report. All had full-thickness tears documented by imaging tests and/or surgical observation; 190 had tears of the supraspinatus, 54 had tears of the infraspinatus, and 13 had tears of the subscapularis. The greatest functional deficits were in the ability to place 8 pounds on a shelf at the level of the head (93% unable), the ability to throw overhand (93% unable), and the ability to sleep on the affected side (86% unable). The SF-36 physical role function and comfort scores were 27% and 48%, respectively, of those of age- and sex-matched controls. Of the variables suggested by a review of the literature, only female sex, involvement of the infraspinatus in the cuff tear, and workers' compensation claims were significantly correlated with lower shoulder function in this series of patients. (J Shoulder Elbow Surg 2000;9:395-402.)

For those of us who grew up in the 1960s, the ubiquity of lasers in modern physical science is astonishing. For the year 2000, for example, the physical science database INSPEC catalogued more than 20,000 entries - about 6% of all abstracts - that contained the word "laser".