Aim: The aim was to report a fenestration technique for gap reduction of acetabular depression fractures. Case presentation: A 76-year-old man suffered from severe left leg pain. The computed tomography scanning showe...Aim: The aim was to report a fenestration technique for gap reduction of acetabular depression fractures. Case presentation: A 76-year-old man suffered from severe left leg pain. The computed tomography scanning showed a displaced acetabular depression fracture, including a third fracture fragment in the center of the acetabular weight-bearing area. We performed a fenestration technique to fenestrate the outer plate of ilium to push down the dislocated fragment of the fracture. The patient was pain-free with good functional outcome of the hip joint at three years after operation. Conclusion: The fenestration technique is useful for displaced acetabular depression fractures. We performed open reduction in this particular case, but the technique may be done less invasively with the use of hip arthroscopy.展开更多
Introduction: To investigate a long-term in vivo deterioration of polymethylmethacrylate (PMMA) bone cement over time, we evaluated retrieved PMMA cement in terms of chemical elements presenting in the cement using en...Introduction: To investigate a long-term in vivo deterioration of polymethylmethacrylate (PMMA) bone cement over time, we evaluated retrieved PMMA cement in terms of chemical elements presenting in the cement using energy dispersive analysis of X-rays;Knoop hardness;and the Young’s modulus using scanning acoustic microscopy. Materials and Methods: For mechanical evaluation, we could neglect the influences of entrapped air bubbles or blood by the use of small specimens. The study was based on thirteen cement samples (six used in the acetabulum and seven in the femur) derived from eight patients (age at revision surgery: mean 72.5, range 68 to 79). All of these samples were Simplex-P?cement. They were functioning well at least ten years after the previous surgery. Duration until revision surgery was ranged 12 to 25 years (average, 17.4 years). The reason for revision was aseptic mechanical loosening. Twenty samples of Simplex-Preg;cement were served by manually mixing as a control. Results: The average of the hardness of the cement was 17.0 ± 1.2 (range, 13.4-20.6). In the control, the hardness was 17.8 ± 1.5 (range, 14.0-24.6). There was no significant difference between these values. The mean of Young’s modulus of the cement was 5.61 ± 0.19 GPa (range, 5.09-6.10). In the control, the modulus was 6.04 ± 0.13 GPa (range, 5.68-6.45). Although the modulus was significantly less than that of the control, there was only 7% decrease in average between twelve and twenty-five years in vivo. Conclusions: Our results suggest that long-term implantation and functional loading in vivo may not be the limiting factor in the mechanical integrity of the bone cement.展开更多
文摘Aim: The aim was to report a fenestration technique for gap reduction of acetabular depression fractures. Case presentation: A 76-year-old man suffered from severe left leg pain. The computed tomography scanning showed a displaced acetabular depression fracture, including a third fracture fragment in the center of the acetabular weight-bearing area. We performed a fenestration technique to fenestrate the outer plate of ilium to push down the dislocated fragment of the fracture. The patient was pain-free with good functional outcome of the hip joint at three years after operation. Conclusion: The fenestration technique is useful for displaced acetabular depression fractures. We performed open reduction in this particular case, but the technique may be done less invasively with the use of hip arthroscopy.
文摘Introduction: To investigate a long-term in vivo deterioration of polymethylmethacrylate (PMMA) bone cement over time, we evaluated retrieved PMMA cement in terms of chemical elements presenting in the cement using energy dispersive analysis of X-rays;Knoop hardness;and the Young’s modulus using scanning acoustic microscopy. Materials and Methods: For mechanical evaluation, we could neglect the influences of entrapped air bubbles or blood by the use of small specimens. The study was based on thirteen cement samples (six used in the acetabulum and seven in the femur) derived from eight patients (age at revision surgery: mean 72.5, range 68 to 79). All of these samples were Simplex-P?cement. They were functioning well at least ten years after the previous surgery. Duration until revision surgery was ranged 12 to 25 years (average, 17.4 years). The reason for revision was aseptic mechanical loosening. Twenty samples of Simplex-Preg;cement were served by manually mixing as a control. Results: The average of the hardness of the cement was 17.0 ± 1.2 (range, 13.4-20.6). In the control, the hardness was 17.8 ± 1.5 (range, 14.0-24.6). There was no significant difference between these values. The mean of Young’s modulus of the cement was 5.61 ± 0.19 GPa (range, 5.09-6.10). In the control, the modulus was 6.04 ± 0.13 GPa (range, 5.68-6.45). Although the modulus was significantly less than that of the control, there was only 7% decrease in average between twelve and twenty-five years in vivo. Conclusions: Our results suggest that long-term implantation and functional loading in vivo may not be the limiting factor in the mechanical integrity of the bone cement.