Joint-preserving surgical treatment options for irreparable posterosuperior rotator cuff tear : Partial repair, superior capsular reconstruction, latissimus dorsi, lower trapezius, or a balloon?

Treatment of irreparable rotator cuff tears in young active patients is challenging. A variety of therapeutic options are available. Only a few joint-preserving treatment options show reliable improvements over a long-term follow-up period. However, the treatment outcomes of joint preservation procedures are not comparable to those of RTSA, as patients are typically younger and have higher expectations. It is remarkable that most of the joint-preserving therapeutic options for irreparable rotator cuff ruptures lack long-term treatment results. This article highlights the indications, technical aspects, and treatment outcomes of the most commonly performed joint-preserving surgeries for irreparable rotator cuff rupture. = Die Behandlung der irreparablen posterosuperioren Rotatorenmanschettenruptur bei jungen, aktiven Patienten stellt eine Herausforderung dar. Es bestehen verschiedene Therapieoptionen. Nur vereinzelte gelenkserhaltende Therapieoptionen zeigen über einen langen Nachkontrollzeitraum verlässliche Verbesserungen der Schulterfunktion und Patientenzufriedenheit. Die Behandlungsergebnisse der gelenkserhaltenden Operationen sind jedoch nicht mit jenen der RTSA vergleichbar, da die Patienten typischerweise jünger sind und höhere Ansprüche haben. Bemerkenswert ist, dass zu den meisten gelenkerhaltenden Eingriffen bei irreparablen Rotatorenmanschettenrupturen Langzeittherapieergebnisse fehlen. In dieser Übersichtsarbeit werden die am häufigsten vorgenommenen gelenkerhaltenden Eingriffe hinsichtlich Indikationen, technischer Aspekte und Behandlungsresultaten beleuchtet

Flow convergence caused by a salinity minimum in a tidal channel

© 2006 The Author et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in San Francisco Estuary and Watershed Science 4 (2006): Issue 3, Article 1.Residence times of dissolved substances and sedimentation rates in tidal channels are affected by residual (tidally averaged) circulation patterns. One influence on these circulation patterns is the longitudinal density gradient. In most estuaries the longitudinal density gradient typically maintains a constant direction. However, a junction of tidal channels can create a local reversal (change in sign) of the density gradient. This can occur due to a difference in the phase of tidal currents in each channel. In San Francisco Bay, the phasing of the currents at the junction of Mare Island Strait and Carquinez Strait produces a local salinity minimum in Mare Island Strait. At the location of a local salinity minimum the longitudinal density gradient reverses direction. This paper presents four numerical models that were used to investigate the circulation caused by the salinity minimum: (1) A simple one-dimensional (1D) finite difference model demonstrates that a local salinity minimum is advected into Mare Island Strait from the junction with Carquinez Strait during flood tide. (2) A three-dimensional (3D) hydrodynamic finite element model is used to compute the tidally averaged circulation in a channel that contains a salinity minimum (a change in the sign of the longitudinal density gradient) and compares that to a channel that contains a longitudinal density gradient in a constant direction. The tidally averaged circulation produced by the salinity minimum is characterized by converging flow at the bed and diverging flow at the surface, whereas the circulation produced by the constant direction gradient is characterized by converging flow at the bed and downstream surface currents. These velocity fields are used to drive both a particle tracking and a sediment transport model. (3) A particle tracking model demonstrates a 30 percent increase in the residence time of neutrally buoyant particles transported through the salinity minimum, as compared to transport through a constant direction density gradient. (4) A sediment transport model demonstrates increased deposition at the near-bed null point of the salinity minimum, as compared to the constant direction gradient null point. These results are corroborated by historically noted large sedimentation rates and a local maximum of selenium accumulation in clams at the null point in Mare Island Strait.The authors acknowledge support for this research from the California Department of Fish and Game, the California Coastal Conservancy, the U.S. Fish and Wildlife Service Coastal Program, and the U.S. Geological Survey Federal/State Cooperative and Priority Ecosystem Science Programs

In-vivo glenohumeral translation and ligament elongation during abduction and abduction with internal and external rotation

Study Design: Basic Science. To investigate humeral head translations and glenohumeral ligament elongation with a dual fluoroscopic imaging system. Background: The glenohumeral ligaments are partially responsible for restraining the humeral head during the extremes of shoulder motion. However, in-vivo glenohumeral ligaments elongation patterns have yet to be determined. Therefore, the objectives of this study were to 1) quantify the in-vivo humeral head translations and glenohumeral ligament elongations during functional shoulder positions, 2) compare the inferred glenohumeral ligament functions with previous literature and 3) create a baseline data of healthy adult shoulder glenohumeral ligament lengths as controls for future studies. Methods: Five healthy adult shoulders were studied with a validated dual fluoroscopic imaging system (DFIS) and MR imaging technique. Humeral head translations and the superior, middle and inferior glenohumeral ligaments (SGHL, MGHL, IGHL) elongations were determined. Results: The humeral head center on average translated in a range of 6.0mm in the anterior-posterior direction and 2.5mm in the superior-inferior direction. The MGHL showed greater elongation over a broader range of shoulder motion than the SGHL. The anterior-band (AB)-IGHL showed maximum elongation at 90° abduction with maximum external rotation. The posterior-band (PB)-IGHL showed maximum elongation at 90° abduction with maximum internal rotation. Discussion: The results demonstrated that the humeral head translated statistically more in the anterior-posterior direction than the superior-inferior direction (p = 0.01), which supports the concept that glenohumeral kinematics are not ball-in-socket mechanics. The AB-IGHL elongation pattern makes it an important static structure to restrain anterior subluxation of the humeral head during the externally rotated cocking phase of throwing motion. These data suggest that in healthy adult shoulders the ligamentous structures of the glenohumeral joint are not fully elongated in many shoulder positions, but function as restraints at the extremes of glenohumeral motion. Clinically, these results may be helpful in restoring ligament anatomy during the treatment of anterior instability of the shoulder

Decreasing survival benefit from cardiac transplantation for outpatients as the waiting list lengthens

AbstractMany patients are accepted for cardiac transplantation during a period of clinical instability associated with a high risk of death, even though most can be discharged home to await transplantation. As the waiting lists lengthen, priority is awarded solely on the basis of the waiting time of outpatients, who now usually undergo transplantation after they have already survived a major period of jeopardy. To determine the impact of the current waiting times and priority system on the previously expected benefit offered by transplantation, 1-year actuarial survival without transplantation was recalculated after each month without transplantation for 214 potential candidates with an ejection fraction of 0.17 ± 0.05 discharged on tailored medical therapy after evaluation. These data were compared with the 1-year survival data of 88 outpatients who underwent transplantation.Actuarial survival after 1 year was 67% on tailored therapy compared with 88% after transplantation (p = 0.009). Death without transplantation was sudden in 43 of 51 patients, resulting from hemodynamic decompensation in 8. For outpatients already surviving 6 months without transplantation, actuarial survival over the next 12 months was 83% without transplantation. Thus, the expected improvement in survival after transplantation would be only 5% over the subsequent year for patients waiting 6 months, which is the waiting time for many outpatients. Such patients should be reevaluated to determine whether transplantation remains indicated during the next year

Serendipitous Kepler observations of a background dwarf nova of SU UMa type

We have discovered a dwarf nova (DN) of type SU UMa in Kepler data which is 7.0 arcsec from the G-type exoplanet survey target KIC 4378554. The DN appears as a background source in the pixel aperture of the foreground G star. We extracted only the pixels where the DN is present and observed the source to undergo five outbursts -- one a superoutburst -- over a timespan of 22 months. The superoutburst was triggered by a normal outburst, a feature that has been seen in all DNe superoutburst observed by Kepler. Superhumps during the super outburst had a period of 1.842+/-0.004 h and we see a transition from disc-dominated superhump signal to a mix of disc and accretion stream impact. Predictions of the number of DNe present in Kepler data based on previously published space densities vary from 0.3 to 258. An investigation of the background pixels targets would lead to firmer constraints on the space density of DN.Comment: Accepted for publication in MNRA