Damborg Frank, Nissen Nis, Jørgensen Hans R I, Abrahamsen Bo, Brixen Kim
Department of Orthopedics, Fredericia and Kolding Hospitals, Denmark.
Acta Orthop. 2008 Aug;79(4):494-8. doi: 10.1080/17453670710015481.
THA changes the pattern of strain distribution in the proximal femur. We quantified the changes in BMD for 5 years after insertion of the cemented Exeter stem in women.
18 women aged 55-79 years, undergoing unilateral THA with the cemented Exeter stem, were included in the study. The BMD was measured in 7 femoral regions of interest according to Gruen, and the contralateral hip and spine using dual-energy X-ray absorptiometry postoperatively, at 18 and at 60 months of follow-up. Results were tested using Wilcoxon matched-pairs signed-rank test.
During the first 18 months, a significant decrease in BMD was seen in zones 2, 3, 6, and 7. No significant changes were seen in zones 4 and 5, in the contralateral hip, or at the spine. In zone 1, there was a small but significant rise in BMD. From 18 to 60 months, we observed a statistically significant rise in BMD in all zones except 4 and 7. Despite this, the total periprosthetic BMD decreased during the follow-up relative to the immediate postoperative situation. There was no significant reduction in BMD in the contralateral hip. In the spine, we observed a significant rise in BMD.
18 months after THA, BMD had decreased in Gruen zones 2, 3, 6, and 7. The bone loss was similar to that seen after other implants and appears to be related to the changes in stress pattern within the proximal femur. At 5 years, BMD had increased again in these zones. It remained lower than baseline, however.
全髋关节置换术（THA）会改变股骨近端的应变分布模式。我们对女性患者植入骨水泥型埃克塞特柄后5年内的骨密度变化进行了量化。
本研究纳入了18名年龄在55 - 79岁之间、接受单侧骨水泥型埃克塞特柄全髋关节置换术的女性患者。术后、随访18个月和60个月时，使用双能X线吸收法在根据Gruen划分的7个股骨感兴趣区域以及对侧髋关节和脊柱测量骨密度。结果采用Wilcoxon配对符号秩检验进行分析。
在最初的18个月内，2区、3区、6区和7区的骨密度显著下降。4区和5区、对侧髋关节以及脊柱未见显著变化。1区的骨密度有小幅但显著的升高。从18个月到60个月，除4区和7区外，所有区域的骨密度均有统计学意义的升高。尽管如此，与术后即刻情况相比，随访期间假体周围的总骨密度仍有所下降。对侧髋关节的骨密度没有显著降低。在脊柱，我们观察到骨密度显著升高。
全髋关节置换术后18个月，Gruen 2区、3区、6区和7区的骨密度下降。这种骨质流失与其他植入物后的情况相似，似乎与股骨近端应力模式的改变有关。5年后，这些区域的骨密度再次升高。然而，仍低于基线水平。
