Interspecies variation in the fibroblast distribution of the anterior cruciate ligament.
BACKGROUND
The future of the treatment of a ruptured anterior cruciate ligament is likely to involve cell-based therapies. These therapies are intrinsically dependent on the cellular distributions in the ligament. Thus, when selecting an animal model for testing of these new treatment methods, it is important to select a model that has similar cellular distributions to that of the normal human anterior cruciate ligament.


OBJECTIVE
There are interspecies differences in the histology of the anterior cruciate ligament.


METHODS
A descriptive histological study comparing the cell and vessel distribution of normal human anterior cruciate ligaments with that of 3 animal models and anterior cruciate ligaments from osteoarthritic human knees.


METHODS
The histology of each of the anterior cruciate ligament sources was quantified in terms of cell number density, expression of alpha-smooth muscle actin, blood vessel density, and cell nuclear morphology using standardized histomorphometric techniques.


RESULTS
The normal human anterior cruciate ligament was similar to the canine anterior cruciate ligament and the anterior cruciate ligament from patients with osteoarthritis with respect to cell density, blood vessel density, and cell nuclear shape. The normal anterior cruciate ligament had significantly fewer vessels than the bovine anterior cruciate ligament and rounder cells than the bovine and ovine anterior cruciate ligaments.


CONCLUSIONS
There is significant interspecies variation in the histology of the anterior cruciate ligament, with the canine anterior cruciate ligament most similar to the human anterior cruciate ligament.


CONCLUSIONS
This finding may have an effect on the accuracy of testing of new, cell-based treatments for the ruptured anterior cruciate ligament, such as guided tissue regeneration.
Department of Orthopedic Surgery, Children's Hospital of Boston, Harvard Medical School, Boston, Massachusetts, USA. martha.murray@tch.harvard.edu
Martha Meaney
MM
Murray
Andreas
A
Weiler
Kurt P
KP
Spindler
D000199:Actins / Q000032:analysis / Q000096:biosynthesis; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000098:blood supply / Q000166:cytology*; D002417:Cattle; D002467:Cell Nucleus / Q000648:ultrastructure; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D005347:Fibroblasts / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000503:physiopathology* / Q000662:veterinary; D012756:Sheep
D000199:Actins