Silver-coated endoprosthetic replacement of the proximal humerus in case of tumour-is there an increased risk of periprosthetic infection by using a trevira tube?

BACKGROUND AND OBJECTIVES: The aim of our study was to evaluate if there is an increased risk of periprosthetic infection (PJI) in patients following replacement of the proximal humerus by using a modular tumour prosthesis in combination with a trevira tube. METHODS: Thirty patients were treated by using a modular tumour endoprosthesis (MUTARS®) following intra-articular resection of the proximal humerus. Fifteen patients received treatment by using a trevira tube. In 15 further cases the use of a trevira tube was not necessary. The mean follow-up time was 26 months (range: 24 months to 84 months). Both, Enneking score and range of motion (ROM), was evaluated. Further radiographs were obtained in two planes. RESULTS: The survival rate one year after surgery was 83 % and 63 % after two years. We recorded a 96 % survival of the limb two years after surgery. We also observed only one case of periprosthetic joint infection (PJI) in the entire follow-up period in one patient who received treatment with a trevira tube. The mean Enneking score was 20 points (range 8 to 26 points). ROM was equal in both study groups. In total 20 % of the treated patients (n = 6) suffered complications. CONCLUSIONS: Replacement of the proximal humerus by using a trevira tube in combination with a modular tumour endoprosthesis is a safe and viable treatment option for both, bone tumours and metastases. There is no statistically significant increased risk of infection by using trevira tube even among immunosuppressed patients. LEVEL OF EVIDENCE: Level 3, retrospective comparative study.

Immunohistochemical and molecular characterization of the human periosteum.

PURPOSE: The aim of the present study was to characterize the cell of the human periosteum using immunohistological and molecular methods. METHODS: Phenotypic properties and the distribution of the cells within the different layers were investigated with immunohistochemical staining techniques and RT-PCR, focussing on markers for stromal stem cells, osteoblasts, osteoclasts and immune cells. RESULTS: Immunohistochemical results revealed that all stained cells were located in the cambium layer and that most cells were positive for vimentin. The majority of cells consisted of stromal stem cells and osteoblastic precursor cells. The density increased towards the deeper layers of the cambium. In addition, cells positive for markers of the osteoblast, chondrocyte, and osteoclast lineages were found. Interestingly, there were MHC class II-expressing immune cells suggesting the presence of dendritic cells. Using lineage-specific primer pairs RT-PCR confirmed the immunofluorescence microscopy results, supporting that human periosteum serves as a reservoir of stromal stem cells, as well as cells of the osteoblastic, and the chondroblastic lineage, osteoclasts, and dendritic cells. CONCLUSION: Our work elucidates the role of periosteum as a source of cells with a high regenerative capacity. Undifferentiated stromal stem cells as well as osteoblastic precursor cells are dominating in the cambium layer. A new outlook is given towards an immune response coming from the periosteum as MHC II positive immune cells were detected.

CYR61 improves muscle force recreation in a rabbit trauma model.

BACKGROUND: Critically elevated compartment pressures after complicated tibial fractures may result in fibrosis and therefore scarring of muscles with impaired function. Several studies have shown a relationship between angiogenesis and more effective muscle regeneration. Cysteine-rich angiogenic inducer 61 (CYR61) is associated with angiogenesis but it is not clear whether it would restore muscle force, reduce scarring or improve angiogenesis after acute musculoskeletal trauma. OBJECTIVE: We researched whether local application of CYR61 (1) restores muscle force, (2) reduces scar tissue formation, and (3) improves angiogenesis. METHODS: We generated acute soft tissue trauma with temporary ischemia and increased compartment pressure in 22 rabbits and shortened the limbs to simulate surgical fracture debridement. In the test group, a CYR61-coated collagen matrix was applied locally around the osteotomy site. After 10 days of limb shortening, gradual distraction of 0.5 mm per 12 hours was performed to restore the original length. Muscle force was measured before trauma and on every fifth day after trauma. Forty days after trauma we euthanized the animals and histologically determined the percentage of connective and muscle tissue. Immunohistology was performed to analyze angiogenesis. RESULTS: Recovery of preinjury muscle strength was significantly greater in the CYR61 group (2.8 N; 88%) as compared to the control (1.8 N; 53%) with a moderate reduction of connective tissue (9.9% vs. 8.5%). Immunohistochemical staining showed that blood vessel formation increased significantly (trauma vs. control 38.75 ± 27.45 mm2 vs. 24.16 ± 19.81 mm2). CONCLUSIONS: Local application of CYR61 may improve restoration of muscle force and accelerate muscle force recovery by improving angiogenesis and moderately reducing connective tissue.

Heterotopic Ossification - Complication or Chance? / Heterotope Ossifikation ­ Komplikation oder Chance?

So far, there has been no clear explanation of the pathophysiological relationships in the development of HO. There is little experimental data dealing with the post-traumatic inflammatory response in terms of a balance between the repair of damaged muscle cells and the opposite response in its development. There are numerous indications regarding possible predisposing factors, such as existence of surrounding tissue hypoxia or the function of pro-angiogenic (VEGF e.g.) and osteoinductive (BMP e.g.) factors. These different scientific approaches offer the opportunity to clinically intervene. In our opinion, early intervention seems to make the most sense in terms of effectiveness and recurrence of HO. An important pathomechanism seems to be chronic inflammation. Currently, non-steroidal anti-inflammatory drugs are the most commonly prescribed prophylaxis drugs. The effectiveness and efficacy of non-steroidal anti-inflammatory drugs is limited by the time-limited release and the side effect potential. Therefore, it is interesting to focus future research towards the cross-talks between immunosuppressive downregulation of the inflammatory response and its effect on the balance between muscle regeneration and the development of HO.

[Diagnosis of Patients with Painful Sacroiliac Joint Syndrome]. / Moderne Diagnostik und minimalinvasive Operationsmethoden bei Patienten mit schmerzhaftem Iliosakralgelenksyndrom.

Pain coming from the sacroiliac (SI) joints can explain up to 25% of all chronic low back pain. A careful differential diagnosis is required to avoid misdiagnosis of low back pain. In addition to historical findings, positive findings on physical examination maneuvers that stress the SI joint are a key component diagnosis. The SI joint is confirmed as a pain generator when intraarticular injection of local anaesthetics provides acute back pain relief. Minimally invasive SI joint fusion is clearly superior to invasive open surgical procedures, with decreased blood loss and tissue disruption, shorter procedure times and shorter hospital stays. Especially well documented are the results of minimally invasive SI joint fusion using iFuse Implant System®. The device's triangular profile, combined with a titanium plasma spray coating, ensures both an immediate and long-lasting joint stabilization.