[Clinical management of rotator cuff tears. Current concepts in cell-based therapy strategies]. / Klinische Versorgung von Rupturen der Rotatorenmanschette. Aktueller Stand der Zelltherapie.

Due to the increasing demand for functionality in an aging yet physically active society, the treatment of rotator cuff tears is of ever-growing importance. Despite intensive research efforts, the treatment of degenerative rotator cuff tears, in particular their long-term outcome, is still a challenge. While in recent years the focus was on biomechanics and the technical aspects of rotator cuff reconstruction, attention has now turned to the biological considerations of tendon regeneration. This article highlights the current state of biological rotator cuff augmentation in a clinical setting and provides an insight into and an outlook on the experimental procedures.

[Quality of life and job performance resulting from operatively treated tibial plateau fractures]. / Lebensqualität und Arbeitsfähigkeit nach operativer Behandlung von Tibiakopffrakturen.

BACKGROUND: The aim of this article is to present the functional results and the effect on quality of life of surgically treated tibial plateau fractures in physically active and working patients with multiple and serious injuries. In addition, the relationships between functional and radiological outcome were evaluated and compared with activity in daily and professional life. PATIENTS AND METHODS: In all, 41 injured patients were followed up a mean of 47 months after surgical treatment and examined with radiological, functional, as well as quality of life score. RESULTS: In the radiological scoring, a mean value of 72 points (max 100 points) was achieved. In the activity score, there was an average of 63.5 points (max 100 points). When evaluating the health-related quality of life, an average score of 69.6 points was achieved. There was a significant relationship between radiological and activity scores and the radiological and life quality scores. Furthermore, the relationship between activity and quality of life scores was considered significant. Surgeon's influence on the functional outcome could be confirmed. CONCLUSION: The functional and the radiological results were moderate. Quality of life was permanently affected by the consequences of tibial plateau fracture in 12 patients; 11 patients were not re-employed. However, the quality of life was assessed as good or very good and 28 patients had returned to work. The quality of life was firmly linked to the radiological and functional parameters, which tended to be influenced by the quality of the primary surgical treatment when looking at the overall population.

Tissue characteristics in tendon-to-bone healing change after rotator cuff repair using botulinumneurotoxin A for temporary paralysis of the supraspinatus muscle in rats.

We hypothesized that botulinumneurotoxin A (BoNtA) positively influences tissue characteristics at the re-insertion site when used as an adjuvant prior to rotator cuff repair. One hundred and sixty Sprague-Dawley rats were randomly assigned to either a BoNtA or saline-injected control group. BoNtA or saline solution was injected into the supraspinatus muscle one week prior to repair of an artificially created supraspinatus tendon defect. Post-operatively, one subgroup was immobilized using a cast on the operated shoulder while the other had immediate mobilization. Histologically, the fibrocartilage transition zone was more prominent and better organized in the BoNtA groups when compared to the saline control group. In the immediately mobilized BoNtA groups significantly more collagen 2 at the insertion was detected than in the control groups (p<0.05). Fiber orientation of all BoNtA groups was better organized and more perpendicular to the epiphysis compared with control groups. Tendon stiffness differed significantly (p<0.05) between casted BoNtA and casted saline groups. Tendon viscoelasticity was significantly higher (p<0.05) in the immobilized saline groups no matter if repaired with increased or normal repair load. The results of this study suggest that reduction of load at the healing tendon-to-bone interface leads to improved repair tissue properties.

Polyethylene wear particles induce TLR 2 upregulation in the synovial layer of mice.

A cellular and receptor mediated response to ultra-high-molecular-weight-polyethylene (UHMWPE) wear particles results in a release of proinflammatory cytokines and induces an inflammatory reaction causing osteolysis in total joint replacement. This investigation offers insight into the toll-like receptor (TLR) mediated activation by polyethylene wear particles in the synovial layer of mice. We hypothesized that, similar to recent in vitro results, UHMWPE particles lead to an upregulation of TLR 1 and 2 and TLR 4 in vivo in the synovial tissue of mice as well. Therefore, UHMWPE particles were generated in a common knee simulator according to the ISO standard, separated by acid digestion and determined by scanning electron microscopy. Endotoxin was removed using a method based on ultracentrifugation. A particle suspension (50 µl; 0.1 vol./vol.%) was injected into the left knee joint of female Balb/c mice (n = 8). In a control group, phosphate-buffered saline was injected into the left knee of Balb/c mice (n = 8). The mice were sacrificed after 7 days. Immunohistochemical staining was performed with TLR 1, 2 and 4 polyclonal antibodies for Balb/c mice and evaluated by light microscopy. The particle-stimulated group showed a thickened synovial layer, an increased cellular infiltration and a TLR 2-upregulation in the synovial layer compared to the control group. An increased expression of TLR 1 and TLR 4 could not be demonstrated. These results indicate a mainly TLR 2-induced inflammation to polyethylene wear debris in the synovial layer of mice.