뼈에 부하자극을 줄때, 가까운 부위는 골막, 먼부위는 골내막 뼈형성이 잘 된다!!

[문형철]

fracture healing환자에게 체중부하는 언제부터 주어야 하고, 어떤 강도로 주어야하는가?

최적의 자극강도는 무엇일까? 

골절재생이 잘 되기 위해서 어느 관절에 체중부하가 주어져야 할까? 

기계적 압박을 가할때 bone formation은 두가지. 

1) periosteal bone formation(골막 뼈형성) - 압박에 가까운 부위

2) endosteal bone formation(골내막 뼈형성) - 압박에서 먼 부위 

참재미있는 결과! 

발목에 부하가 주어질때, periosteal bone formation은 발목 가까운 부위가 더 많이 됨. 

그런데, endosteal bone formation은 발목에서 먼부위에서 더 많이 형성!

panic bird...

이 질문에 대한 해답을 구하고 있다. 

2009년 논문이다. 

Joint loading-driven bone formation and signaling pathways predicted from genome-wide expression‎ profiles

abstract

Joint loading is a recently developed loading modality that induces anabolic responses by lateral loads applied to a synovial joint such as an elbow and a knee. The present study extended this loading modality to an ankle and addressed a question: 

does ankle loading promote bone formation in the tibia? 

If so, what signaling pathways are involved in the anabolic responses? 

Using C57BL/6 female mice as a model system, lateral loads of 0.5 N were applied to the ankle at 5 Hz for 3 min/day for 3 consecutive days and load-driven bone formation was eval‎uated at three tibial cross-sections (the proximal, middle,

and distal diaphysis). Furthermore, total RNA was isolated for 3 pairs of microarray experiments as well as quantitative real-time PCR analyses. 

The histomorphometric results revealed that in all cross-sections ankle loading elevated the cortical area and thickness as well as the calcein-labeled surface. Signaling pathway analysis from microarray-derived whole-genome mRNA expression‎ profiles and quantitative real-time PCR predicted that molecules in phosphoinositide 3-kinase (PI3K), ECM-receptor interactions, TGFβ signaling, and Wnt signaling were involved in the joint-loading driven responses. Since ankle

loading stimulates bone formation throughout the tibia both in the endosteum and the periosteum, it may provide a non-pharmacological approach to effectively activate molecular signaling necessary for preventing bone loss.

Summary of loading effects on the periosteum and endosteum in the mouse diaphysis

Fig. 1. Experimental setup. (A) Mouse on a loading table for ankle loading. (B) Schematic diagram illustrating the piezoelectric mechanical loader. (C) Location of three cross-sections

for bone morphometry. (D) Strain measurements with ankle and knee loading. The best-fit regression line is: y=12.4 x+3.7 with ankle loading (r2=0.99), and y=4.8 x+1.2 with

knee loading (r2=0.99).

Increase in bone morphometric parameters with ankle loading

무지막지하게 어려운 healing pathway

Summary of bone formation rate with joint loading

- 와우 완전 재미있네 ㅎㅎㅎ