Healing Potential of the Anterior Cruciate Ligament Remnant Stump.
OBJECTIVE
The aim of this study was to analyze the microstructural architecture and cellular differentiation of the anterior cruciate ligament (ACL) stumps in different stages after injury, as this could augment graft biointegration.


METHODS
The histological appearance and immunoreaction for cluster of differentiation 34 antigen (CD34) of 54 biopsies from 27 remnants were compared to 10 biopsies from 5 normal cruciate ligaments.


RESULTS
CD34 reaction in endothelial cells, fibroblasts and fibrocytes was consistently positive in small synovial vessels. Remnants also exhibited CD34(+) cells among collagen fibers. Blood vessel density varied between specimens. The mean vascular microdensity was 43 per ×200 field in remnants compared to 15.2 in controls. A total of 94.44% of remnant ACL samples had significant hyperplasia of stellate and fusiform stromal cells, CD34(+); 22.4% had developed capillary vessels inside the ligament; 33% exhibited ongoing angiogenesis.


CONCLUSIONS
Significant differences exist between torn and intact ACL regarding microvascularization. The remnants contain stellate stromal cells and CD34(+) fibrocytes, and display angiogenesis both at synovia as well as in the ligament itself. These findings underline the potential contribution to neoligament healing when remnants are preserved.
Department of Orthopedics and Trauma, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania.
Ilie
I
Trocan
Department of Microscopic Morphology/Histology, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania.
Raluca A
RA
Ceausu
Department of Microscopic Morphology/Histology, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania.
Andreea A
AA
Jitariu
Department of Orthopedics and Trauma, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania horia.haragus@yahoo.com.
Horia
H
Haragus
Faculty of Medicine, Dentistry and Pharmacy, Vasile Goldis Western University, Arad, Romania.
Gratian
G
Damian
Department of Microscopic Morphology/Histology, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania Angiogenesis Research Center, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania.
Marius
M
Raica
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000098:blood supply / Q000503:physiopathology*; D000070598:Anterior Cruciate Ligament Injuries / Q000378:metabolism / Q000503:physiopathology*; D018952:Antigens, CD34 / Q000378:metabolism; D001808:Blood Vessels / Q000166:cytology / Q000378:metabolism / Q000503:physiopathology*; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000166:cytology / Q000378:metabolism; D014945:Wound Healing; D055815:Young Adult
D018952:Antigens, CD34
Anterior cruciate ligament (ACL); CD34+; angiogenesis; remnant stump; stellate cells