Biceps Tenodesis and Intra-articular Decompression for Treatment of Superior Labral Tear from Anterior to Posterior and Associated Paralabral Cyst in Active Duty Military.

Background: To examine the outcomes of combined biceps tenodesis and indirect, intra-articular arthroscopic paralabral cyst decompression for the treatment of active duty military patients with superior labral from anterior to posterior tears and associated paralabral cysts. Methods: Retrospective chart review of all active duty patients at our institution from 2011 to 2014 with superior labral from anterior to posterior tears and associated paralabral cysts at the spinoglenoid notch treated with biceps tenodesis and indirect arthroscopic cyst decompression. Patient charts were examined for pre- and post-operative parameters including strength, range of motion, visual analog scale pain score, American Shoulder and Elbow Surgeon Score, and Single Assessment Numeric Evaluation Score. Results: Seven patients met study criteria. All patients presented with chronic shoulder pain and decreased external rotation strength, and three patients had clinically apparent muscular atrophy. Pre- and post-operative assessment showed external rotation strength increased from a median of 4 (range 4-4) to 5 (range 4-5; p-value = 0.014), Single Assessment Numeric Evaluation increased from a median of 50 (range 0-70) to 75 (range 30-95; p-value = 0.031), American Shoulder and Elbow Surgeon increased from a median of 46.0 (range 32.0-58.0) to 66.5 (range 58.0-98.0; p-value = 0.068), and visual analog scale pain score decreased from a median of 3 (range 1-8) to 0 (range 0-5; p-value = 0.017). Median follow-up was 66 wk (range 36-138 wk). The change was statistically significant (p <0.05) for external rotation strength, Single Assessment Numeric Evaluation, and VAS reduction. Post-operatively, all patients returned to full duty at a median of 20 wk (range 12-36 wk). Conclusion: The use of biceps tenodesis in conjunction with indirect, intra-articular arthroscopic paralabral cyst decompression is an effective technique in an active patient population with superior labral from anterior to posterior tear with associated paralabral cyst.

Assembly and Calcium Binding Properties of Quantum Dot-Calmodulin Calcium Sensor.

We have developed the first nanoengineered quantum dot molecular complex designed to measure changes of calcium ion (Ca2+) concentration at high spatial and temporal resolutions in real time. The sensor is ratiometric and composed of three components: a quantum dot (QD) emitting at 620 nm as a fluorescence donor, an organic dye (Alexa Fluor 647) as a fluorescence acceptor, and a calmodulin-M13 (CaM-M13) protein part as a calcium sensing component. In this work, we have determined the maximal number of CaM-M13 required for saturating a single QD particle to be approximately 16. The dissociation constant, Kd of the QD-based calcium ion sensor was also estimated to be around 30 microM.

High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

PURPOSE: To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. METHODS: Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. RESULTS: In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). CONCLUSIONS: In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. CLINICAL RELEVANCE: The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair strength compared with high-tensile strength suture at time-zero simulated testing.