[From Pathomorphology to Hip Osteoarthritis - Femoroacetabular Impingement as an Example]. / Von der Fehlform zur Coxarthrose ­ Beispiel Hüftimpingement.

From Pathomorphology to Hip Osteoarthritis - Femoroacetabular Impingement as an Example Abstract. Femoroacetabular impingement (FAI) occurs due to abnormal morphology and subsequent contact between the proximal femur and the acetabulum and can be a source of labral and chondral damage in the hip joint. While there is evidence that Cam-type FAI is correlated with hip osteoarthritis, there is yet no clear link between osteoarthritis and Pincer-FAI in which primarily the labrum gets injured. Hips with evident deformity and beginning chondral and/or labral damage should undergo surgery. Most cases (80-90 %) can be successfully treated by hip arthroscopy. At the time of surgery, the typical FAI-patient is 30 years old. With correct indication and proper surgical technique, favorable outcomes are achieved in more than 80 % of the cases at a short- to mid-term follow-up.

[Biomechanical properties of articular cartilage after high hydrostatic pressure treatment]. / Biomechanische Eigenschaften von Gelenkknorpel nach hydrostatischer Hochdruckbehandlung.

AIM: Reconstruction of bone defects due to malignant tumors can be realized by several methods. Up to now, two methods, irradiation and autoclaving, are available for extracorporeally devitalizing resected tumor-bearing osteochondral segments. Previous investigations have shown that human normal and tumor cells in culture were irreversibly impaired when subjected to extracorporeal high hydrostatic pressure (HHP) of 350 MPa. The aim of this study was to examine the biomechanical and immunohistochemical properties of cartilage after exposure to HHP MATERIALS AND METHODS: Osteochondral segments of bovine femoral condyles were exposed to pressure of 300 and 600 MPa (n=20 each). Biomechanical and biological properties of untreated and treated segments were evaluated by repetitive ball indention testing and immunohistochemical labelling aggrecan, link protein and collagen II. The contralateral segments served as untreated control. RESULTS: No significant alterations concerning stiffness and relaxation of osteochondral segments even after 600 MPa were observed. Immunohistochemically, staining was positive in all cases and no differences in the labeling pattern of proteoglycanes were observed between untreated and HHP-treated specimens. CONCLUSION: These findings give hope that HHP eventually will be used as a new gentle way of treating resected cartilage and bone without alteration of biomechanical properties to inactivate tumor cells in order to allow autologous reimplantation.

High hydrostatic pressure-induced cell death in human chondrocytes and chondrosarcoma cells.

BACKGROUND: In orthopedic surgery, sterilization of bone used for reconstruction of osteoarticular defects caused by malignant tumors is carried out in different ways. At present, to devitalize tumor-bearing osteochondral segments, extracorporal irradiation or autoclaving is mainly used, although both methods have substantial disadvantages, e.g. loss of biomechanical and/or biological integrity of the bone and destabilization of the articular surface. In this regard, high hydrostatic pressure (HHP) treatment of bone is a new, advancing technology, now being used in preclinical testing to inactivate tumor cells. To find out if this technique is also suited for extracorporal inactivation of chondrocytes and chondral tumor cells, the effect of HHP on cell viability and morphology of human chondrocytes / chondrosarcoma cells was investigated in the present study. MATERIALS AND METHODS: SW1353 chondrosarcoma cells and chondrocytes were subjected to HHP in the range of 50 to 350 MPa (10 min, 37 degrees C) and, subsequently, cell viability and cell morphology assessed. RESULTS: After exposure at 350 MPa, all HHP-treated chondral cells showed explicit morphological changes, evident by membrane ruffling and bleb formation; chondrosarcoma cells treated this way were irreversibly damaged and not alive. CONCLUSION: We anticipate that, in orthopedic surgery, HHP eventually can serve as a novel, promising technical approach for cell inactivation (including tumor cells) and allow subsequent reimplantation of the osteoarticular autograft.