Introduction: Scapular manipulation is one of the most successful techniques for reducing anterior shoulder dislocations. However, as there is evidence in the literature that elbow flexion can avoid tendon interposition and muscular compression forces on the glenohumeral joint are at a minimum in the overhead position, we created a modification of the original technique with the principle of scapular manipulation in overhead position and traction on the upper arm with the elbow flexed. The aim of this study was to assess the effectiveness of this new method.

Methods: 62 patients with acute anterior shoulder dislocation who were treated with this new method were evaluated prospectively with regard to primary success rate and reduction time as main outcome parameters. Results were compared to the published data on the original method. Statistics was conducted using the chi-square test and the ANOVA post hoc test with Bonferroni-Dunn-transformation.

Results: 59 of the 62 dislocations (61% first time dislocations, 21% with associated fractures) were reduced successfully by use of the new method by 21 different physicians indicating a primary success rate of 95.2%. The mean reduction time was 3.13 minutes. Primary success rates of the original method reported in 5 studies range from 78.4 to 96.0% (mean 87.1%). In 2 out of 5 single test and global level comparisons our new modification revealed a statistically significant better primary success rate compared to the original method (p< 0.05). There were no iatrogenic complications in our study, and the method was easy to perform even without any experience in reducing shoulder dislocations.

Conclusion: Modification by overhead position and elbow flexion can even improve the high primary success rate of the original scapular manipulation technique. Therefore, the method is strongly recommended as a first choice technique for reducing anterior shoulder dislocations.

In tissue engineering, scaffolds are vitalized by cells in vitro. Human mesenchymal stem cells (hMSC) are very interesting because of their ability to differentiate towards the osteogenic lineage and their self renewing capacity. Yet, it is important that implanted cells do not disseminate and exhibit unwanted cell growth outside the implantation site. Therefore the aim of this study was to detect migrated cells in organs of mice after implantation of a composite (cell-scaffold) substitute.

HMSC (Cambrex, USA) were inoculated on a clinically approved 3D scaffold (Tutobone(TM), Tutogen, Germany). One composite and one scaffold without cells were implanted subcutanously, left and right paravertebrally in athymic nude mice (nu/nu). After 2, 4, 8 and 12 weeks constructs were explanted and organs (liver, spleen, lungs, kidney, heart, testicles, brain and blood) were harvested. The entire organs were homogenized and genomic DNA was isolated for qualitative and quantitative PCR.

Human DNA was found in all explanted composites at all examined time points. No human DNA could be detected in control scaffolds. Moreover we did not detect human DNA in all explanted organs at any time point. As internal controls we could detect 1 single hMSC in a pool of 106 mouse cells.

In conclusion, we could proof that cells of implanted composite substitutes do not migrate to other organs. Furthermore, this study showed that implanted hMSC seeded on 3D scaffolds survive over time frames up to 12 weeks.