کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2781675 1153331 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of age and mechanical stability on bone defect healing: Age reverses mechanical effects
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شناسی تکاملی
پیش نمایش صفحه اول مقاله
Influence of age and mechanical stability on bone defect healing: Age reverses mechanical effects
چکیده انگلیسی

Non-unions and delayed healing are still prevalent complications in fracture and bone defect healing. Both mechanical stability and age are known to influence this process. However, it remains unclear which factor dominates and how they interact. Within this study, we sought a link between both factors.In 36 female Sprague–Dawley rats, the left femur was osteotomized, distracted to an osteotomy gap of 1.5 mm and externally fixated. Variation of age (12 vs. 52 weeks — biologically challenging) and fixator stiffness (mechanically challenging) resulted in 4 groups (each 9 animals): YS: young semi-rigid, OS: old semi-rigid, YR: young rigid and OR: old rigid. Qualitative and quantitative radiographical analyses were performed at weeks 2, 4 and 6 after surgery. Six weeks post-op, rats were sacrificed and femora were harvested for biomechanical testing (torsional stiffness (TS) and maximum torque at failure (MTF)).Six weeks after surgery, TS showed a significant interaction between age and fixation stiffness (p < 0.0001). TS in YR was significantly higher than that in the other groups (YS: p < 0.001; OR: p < 0.001; OS: p < 0.001). Additionally, YS showed a significantly higher TS compared to the OS (p = 0.006) and OR (p = 0.046). Testing of MTF showed a significant interaction of both variables (p = 0.0002) and led to significant differences between OR and YS (p < 0.001), OS (p = 0.046) and YR (p < 0.001). The YR showed a higher MTF compared to YS (p = 0.012) and OS (p = 0.001), whereas OR's MTF was inferior compared to OS. At 2-week follow-up, YR (p = 0.006), and at 6-week follow-up, YS and YR (p = 0.032) showed significantly higher radiographic scores. At 2-week follow-up, YS's callus was larger than that of the old groups (OS: p = 0.025; OR: p = 0.003). In YR a significantly smaller callus was observed compared to YS at time points 4 and 6 weeks (p = 0.002 for both) and compared to OS at 6-week follow-up (p = 0.03).The effect of age seems to invert the effect of mechanical properties of the callus, which was not correlated to callus size. Optimization of mechanics alone seems to be not sufficient. The underlying mechanisms and causes of the age-related influences and their clinical counterparts need to be further investigated.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Bone - Volume 42, Issue 4, April 2008, Pages 758–764
نویسندگان
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