Background: Fractures of the humeral head are a relevant problem in orthopedic surgery and the optimal therapeutic strategy of displaced fractures remains debated controversially in literature. In this respect, a special locking-plate was designed recently for the humerus to improve fixation of open reduction. However, analysis of larger series are still missing. Hence, the aim of this study was to analyze prospectively all patients suffering from humeral head fractures which were stabilized by the internal fixation system PHILOS (Synthes).

Patients and Methods: From 01/2002 until 08/2005 225 displaced humeral head fractures were treated by PHILOS plates. The fractures were classified according to the classification of Neer. Mean observation period was 9 months postoperative. For clinical evaluation the constant score was calculated after a mean observation period of 9 months. Moreover, an X-ray was performed in two plains to judge the implant position. From the total collective of 225 patients, an amount of 176 patients were enclosed into the clinical evaluation. The others were either deceased, or could not be contacted for other reasons.

Results: Out of the enrolled 176 patients into the follow-up study, 35% were Neer III, 43% were Neer type IV/V-3, and Neer type IV/V-4 were found in 12% beside 10% others. After 9 months, the mean constant score was absolute 75 ± 17 points. In direct postoperative X-ray of the 225 patients, a correct reduction and adequate axis between head and shaft was found in 92% of the patients. However, in 14% incorrect implant position was present in terms of intraarticular screws (11%) and elevated plate position in 6 cases. Moreover, after 9 months 8 patients demonstrated secondary implant dislocation, 3 of the head and 5 of the shaft and 14% suffered from secondary screw perforation into the joint due to humeral head sintering. Complete necrosis of the humeral head was present in 5 cases whereas partial necrosis was proven in 9 patients. Since sometimes, several complications were present in a single patient, the total amount of complication cases was 29 and these patients required secondary surgery.

Conclusion: The PHILOS locking plate system allows for an reliable internal fixation of humeral head fractures presenting a reasonable low complication rate. However, surgical pearls comprise mandatory cerclages of both tubercula framed onto the plate and correct axis of humeral head reposition. Typical pitfalls are intraarticular screws, secondary sintering and mislead anticipation of the stronghold of screw fixation in the bone by the locking mechanism. An randomized prospective study is currently on the way to further illuminate the quality of locking plate systems in the humeral head.

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.