Varying development of femoral and tibial subchondral bone tissue and their interaction with articular cartilage during progressing osteoarthritis.

INTRODUCTION: Differences between tibial and femoral joint surfaces and knee compartments concerning coupled bone and cartilage turnover or bone-cartilage cross talk have not been previously examined, although the mechanical and biological interaction of the mineralized subchondral tissues with articular cartilage is of great importance for advancing osteoarthritis. MATERIALS AND METHODS: Therefore, with the help of immunohistochemistry and real-time polymerase chain reaction (RT-PCR), human knee joint cartilage tissue was investigated for expression of key molecules of the extracellular matrix and cartilage composition (collagen type I and II, aggrecan) plus proteoglycan content (colorimetric analysis). Furthermore, we correlated the results with 3D microcomputed tomography of the underlying subchondral bone (high-resolution micro-CT system). Measurements were performed in dependence of the anatomical site (femoral vs. tibial, medial and lateral each) to identify regional differences during the osteoarthritic process. From an enduring series of 108 patients undergoing implantation of TKA, 34 osteochondral samples with lesions macroscopically classified as ICRS grade 1b (group A) and 34 samples with ICRS grade 3a/3b lesions (group B) were compared with 21 healthy controls. RESULTS: Concerning 3D analysis, the medial femoral condyle and tibia showed the most significant increase in bone volume fraction and a decrease in the trabecular number in group B frequently accompanied by subchondral bone resorption pits and enchondral ossification. Under physiological conditions, tibia plateaus show lower bone volume fraction than the corresponding femoral site and this difference enlarges with advancing OA. Partially even contradictory behavior was observed such as trabecular separation at the lateral tibial and medial plateau in osteochondral OA samples of the same patients. Collagen type II expression levels show faster and varying changes than type I during the OA process, leading to a lower positive or negative correlation with bone microstructural analysis, especially on the tibia plateau. CONCLUSIONS: Structural bone and cartilage parameter changes showed varying developments and correlations among each other in the different compartments of the knee. As a clinical conclusion, therapies to postpone or prevent cartilage degeneration by influencing the loss of mineralized bone could be site dependent.

Regional differences of tibial and femoral cartilage in the chondrocyte gene expression, immunhistochemistry and composite in different stages of osteoarthritis.

The function of articular cartilage as an avascular tissue is mainly served by collagen type II and proteoglycan molecules. Within this matrix homeostasis between production and breakdown of the matrix is exceptionally sensitive. The current study was conducted to identify regional differences in specific alterations in cartilage composition during the osteoarthritic process of the human knee joint. Therefor the changes in the expression of the key molecules of the extracellular matrix were measured in dependence of the anatomical side (femoral vs tibial) and associated with immunohistochemistry and quantitative measurement. 60 serial osteochondral femoral condyle and the tibial plateau samples of patients undergoing implantation of total knee endoprosthesis of areas showing mild (Group A, macroscopically ICRS grade 1b) respectively advanced (Group B, macroscopically ICRS grade 3a/3b) (30 each) osteoarthritis according to the histological-histochemical grading system (HHGS) were compared with 20 healthy biopsies with immunohistochemistry and histology. We quantified our results on the gene expression of collagen type I and II and aggrecan with the help of real-time (RT)-PCR. Proteoglycan content was measured colorometrically. In group A slightly increased colour intensity was found for collagen II in deeper layers, suggesting a persisting but initially still intact repair process. But especially on the medial tibia plateau the initial Col II increase in gene expression is followed by a decrease leading to the lowest over all Col II expression on the medial plateau, here especially in the central part. There in late stage diseases the collagen type I expression was also more pronounced. Markedly decreased safranin O staining intensity was observed in the radial zone and less reduced intensity in the transitional zone with loss of zonal anatomy in 40% of the specimens in group A and all specimens in group B. Correlation between colorometrically analysed proteoglycan GAG content and aggrecan Real Time PCR is mainly weak. Tibial and femoral cartilage in contrast to patellar cartilage both are preferential exposed to compressive stresses, but presence of menisci affects the load distribution at the tibial side, which creates varying conditions for the different cartilage surfaces in the knee. As directly measured Poissons ratio in tibial cartilage is higher but Younǵs modulus is lower than in femoral cartilage, different resulting feedback amplification loops interact with proceeding cartilage damage. The initial loss of aggrecan may support Matrix metalloproteinases (Mmps) in the access to the collagen network and the considerably differing mechanical properties at both joint surfaces result in varying increased synthesis and release of matrix degrading enzymes. The present study has identified a selection of events which reflect the response of cartilage structure and composite, chondrocytes itself and their productivity to changes in mechanical stress depending on the anatomical site.

[Important Aspects of Diagnosis and Minimally Invasive Treatment of Metastases in the Spine Through the Plasma Field Therapy (Cavity Coblation Method)]. / Besonderheiten der Diagnostik und der minimalinvasiven chirurgischen Behandlung von multiplen Metastasen an der Wirbelsäule durch Plasmafeldtherapie (Cavity-Coblation-Methode).

Background and objectives: Until recently, it was almost impossible to perform major surgery on metastases in the spine. This is especially the case for multiple spinal metastases and for older multi-morbid patients with higher OP risks. It is very important in such cases that the operation should be as minimally invasive as possible, and should aim to reduce pain, treat fractures and to improve the quality of life. The aim of this publication is to present and discuss the specific features of the methodology, problems, surgical techniques, as well as the effectiveness of the modernised cavity/coblation method and results of the treatment of 240 patients with spine metastases. Patients/Material and Method: Patients: Patients of every age with bone destruction were treated, with osteolysis and pathological fractures of vertebrae caused by metastases. The pre-operative diagnosis was evaluated by X-Ray, MRT, CT, whole-body F18-FDG-PET, whole-body bone scintigraphy, histology. Cavity/coblation method: Tumour resection was carried out by the plasma field (42 °C, cold energy) over the percutaneous trans-/extrapedicular access and was followed by balloon kyphoplasty. Tumour tissue was removed, deformation corrected and stability enhanced. The treatment clearly reduced the risks of recurrence, fracture and compression of the neural structures. Local radiotherapy and chemotherapy were performed post-operatively. Clinical and radiological follow-ups, included tumour staging, were performed regularly after the OP (after 2 and 14 days and 3, 6,12, 24, 36, 48 and 60 months), including data on pain and improvement in quality of life. Results: Within 6 years (03/08-04/14), we treated 240 patients with multiple spinal metastases (146 female, 94 male, age range 31-92 years, average age 65.5 years) or 784 vertebral bodies. 61 patients were also given dorsal percutaneous instrumentation and straightening. All patients experienced a significant reduction in pain, and improvements in satisfaction and quality of life. Treatment was combined with chemotherapy and local radiotherapy to reduce tumour cell growth or recurrence rate. Patients could be rapidly mobilised after surgery, blood loss was minimal, and the next oncology treatment could be initiated immediately. Discussion/Conclusions: Cavity/coblation is a safe and minimally invasive procedure, as confirmed by our own short- and long-term results, as well as by reports/publications of other workers. OP risks, blood loss, and surgical time are lower and shorter. This new method is very promising for the future. It is important that the indication is correct and the treatment strategy must be adapted individually. Prognosis must be assessed and the surgical technique must be precise.

[Tumours and metastases of the spine : cavity/coblation surgery and vertebroplasty/kyphoplasty]. / Tumoren und Metastasen an der Wirbelsäule : Cavity/Coblation-Operation und Vertebro-/Kyphoplastie.

BACKGROUND: Radical surgery for metastases in the spine is in many cases not possible, includingthe higher risk of surgery in older patients with co-morbidities. The aims of treatment are: minimally invasive and maximally effective tumour removal, fracture position, stabilization, pain reduction, and improved quality of life. The specific features and problems of diagnosis and treatment using the cavity/coblation method, , the surgical technique, and the results of the treatment of 250 patients with spinal tumours/metastases are presented. MATERIALS AND METHODS: Tumour resection is carried out by plasma field, via percutaneous trans-/extrapedicular access, followed by kyphoplasty. Clinical and radiological follow-up was carried out postoperatively, including data on pain reduction and improvement of quality of life. RESULTS: Within 6 years (March 2008t February 2014) a total of 250 patients, or 812 spines were treated. In 59 cases dorsal percutaneous instrumentation and straightening were carried out. Minimal blood loss and a very low complication rate were recorded. After surgery, significant pain reduction, satisfaction, early mobilization, and improvement in quality of life were demonstrated in all patients. Immediate radio- and chemotherapy could be carried out. In 38 cases cement escaped laterally into the intervertebral space, but this had no clinical relevance. 188 patients have since died because of tumour manifestations. CONCLUSIONS: The cavity/coblation method has been demonstrated to be a safe, minimally invasive procedure, with good short- and long-term results and lower complication rates. A comprehensive diagnostic, including tumour staging, the correct indication, and prognosis estimation, is important.

[Minimally invasive treatment of tumours and metastases in the spine by plasma field therapy (cavity coblation) and vertebro-/kyphoplasty with and without additional dorsal percutaneous instrumentation]. / Minimalinvasive Therapie der Tumoren und Metastasen der Wirbelsäule durch Plasmafeldtherapie (Cavity Coblation) und Vertebro-/Kyphoplastie mit und ohne zusätzliche dorsale perkutane Instrumentation.

BACKGROUND: Realisation of a major operation of tumours/metastases in the backbone is in many cases not possible, above all in older multimorbid patients with higher OP risks. So it is important to proceed here so minimally invasive as possible, but at least actually to reduce above all pain for the patient and the danger of other fractures and deformations and to improve thereby the quality of life. The modern method of the percutaneous cavity coblation by plasma field has been known for a short time and has been used by us for 5.5 years successfully. The aim of this work is to present the specific features of the methodology, problems, OP technology, results of the treatment of more than 218 patients with spine tumours/metastases. PATIENTS/MATERIAL AND METHODS: Old and young patients with spinal tumours (painful large haemangiomas) and metastases were treated. The Cavity SpineWand device (ArthroCare) provides a space in the tumour by patented coblation technology (coblation = controlled ablation, based on plasma-provided high-frequency energy) and can be used with additional procedures such as, for example, cement injection for vertebral stabilisation - kypho-/vertebroplasty. Access to the backbone occurs percutaneously and transpedicularly, in some cases extrapedicularly. By the removal of tumour tissue not only space for the cement replenishment is achieved, but also complete destruction/vaporisation of the tumour cells. Recurrence risk, fracture danger and compression of the neural structures are clearly reduced thereby. RESULTS: Within the 5.5 years (03/2008-09/2013) we treated 218 patients (144 f., 74 m., age 31-92 years) with spinal tumours and backbone metastases with this method. In 59 cases it was carried out in addition to dorsal percutaneous instrumentation and erection. RESULTS of clinical and radiological evaluations were assessed at 2 and 14 days as well as at 3, 6, 12, 24, 36, 48 and 60 months post-surgery (but not for control with all patients on account of the shorter method application time). A clear pain reduction and with it satisfaction and quality of life improvement were seen for all patients. In several cases treatment was combined with chemotherapy or radiotherapy by which also tumour cell growth or recurrence could be clearly diminished. Patients could be mobilised quickly after surgery, blood loss was minimal, further oncological treatment could be initiated immediately. Especially for haemangiomas in one or several levels with massive bleeding tendency and danger of cement embolism, these risk factors were clearly minimised by ablation and coagulating the tumour vessels. COMPLICATIONS: in 29 cases with especially large osteolytic defects slight cement escape was observed paravertebrally (forwards, lateral and in the intervertebral disc field), without clinical relevance, an intervention was not necessary. 65 patients (43 f., 22 m.) died due to tumour intoxication. CONCLUSION: The percutaneous cavity coblation method for the treatment of tumours and metastases in the spine represents a sure, minimally invasive procedure for patients as demonstrated by short-term and long-term results. Due to the percutaneous, minimally invasive access, the OP risks, especially blood loss and OP times are clearly low and shorter. This new method is as yet only available in a few medical centres in Germany as well as in other countries but at the moment it is being used successfully and from our point of view has a promising future.