The effect on the extracellular matrix of the deep fascia in response to leg lengthening.
BACKGROUND
Whereas the alterations of diverse tissues in cellular and molecular levels have been investigated during leg lengthening via microscopy and biochemical studies, little is known about the response of deep fascia. This study aims to investigate the changes of the extracellular matrix in deep fascia in response to leg lengthening.


METHODS
Animal model of leg lengthening was established in New Zealand white rabbits. Distraction was initiated at a rate of 1 mm/day and 2 mm/day in two steps, and preceded until increases of 10% and 20% in the initial length of tibia had been achieved. Alcian blue stain and picrosirius-polarization method were used for the study of the extracellular matrix of deep fascia samples. Leica DM LA image analysis system was used to investigate the quantitative changes of collagen type I and III.


RESULTS
Alcian blue stain showed that glycosaminoglycans of fascia of each group were composed of chondroitin sulphate and heparin sulphate, but not of keratan sulphate. Under the polarization microscopy, the fascia consisted mainly of collagen type I. After leg lengthening, the percentage of collagen type III increased. The most similar collagen composition of the fascia to that of the normal fascia was detected at a 20% increase in tibia length achieved via a distraction rate of 1 mm/d.


CONCLUSIONS
The changes in collagen distribution and composition occur in deep fascia during leg lengthening. Although different lengthening schemes resulted in varied matrix changes, the most comparable collagen composition to be demonstrated under the scheme of a distraction rate of 1 mm/day and 20% increase in tibia length. Efficient fascia regeneration is initiated only in certain combinations of the leg load parameters including appropriate intensity and duration time, e.g., either low density distraction that persist a relatively short time or high distraction rates.
Wang
Hai-Qiang
HQ
Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China, 710032. wanghaiqiangfmmu@hotmail.com
Li
Xin-Kui
XK
Wu
Zi-Xiang
ZX
Wei
Yi-Yong
YY
Luo
Zhuo-Jing
ZJ
D000423:Alcian Blue; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001852:Bone Lengthening / Q000379:methods*; D002809:Chondroitin Sulfates / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D004396:Coloring Agents; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism*; D005205:Fascia / Q000378:metabolism* / Q000473:pathology; D000071938:Fasciotomy; D006493:Heparin / Q000031:analogs & derivatives / Q000378:metabolism; D006614:Hindlimb; D007091:Image Processing, Computer-Assisted; D008859:Microscopy, Polarization; D011509:Proteoglycans / Q000378:metabolism; D011817:Rabbits; D013314:Stress, Mechanical
D015415:Biomarkers; D024042:Collagen Type I; D024061:Collagen Type III; D004396:Coloring Agents; D011509:Proteoglycans; C036090:heparin proteoglycan; D006493:Heparin; D002809:Chondroitin Sulfates; D000423:Alcian Blue