Traumatic anterior cruciate ligament tear and its implications on meniscal degradation: a preliminary novel lapine osteoarthritis model.
BACKGROUND
Injury patterns of the meniscus following impact trauma resulting in anterior cruciate ligament (ACL) rupture are not well understood. This study explored the spatial and temporal distribution of meniscal tears in a novel in vivo lapine model.


METHODS
Skeletally mature Flemish Giant rabbits were subjected to either tibiofemoral impaction resulting in ACL rupture or surgical ACL transection. Meniscal damage was assessed acutely and after 12 wk for traumatically torn, and after 12 wk in ACL transected animals. Morphological grading was assessed using previously established criteria, and descriptions of meniscal damage were diagnosed by a Board certified orthopedist. Histological assessment was also made on 12 wk traumatically torn and ACL transected animals using Fast-Green/Safranin-O staining.


RESULTS
Traumatic ACL rupture resulted in acute tears predominately in the lateral menisci. Animals subjected to both surgical transection and traumatic ACL rupture experienced degradation of the lateral and medial menisci 12 wk after injury. However, traumatic ACL rupture resulted in acute lateral damage and chronic degradation of the menisci, as well as more severe degradation of the menisci 12 wk after injury.


CONCLUSIONS
This study showed that unconstrained high-intensity impacts on the tibiofemoral joint lead to meniscal damage in conjunction with ACL ruptures. Both acute and chronic changes to the menisci following traumatic impaction were observed. This research has implications for the future use of lapine models for osteoarthritis, as it incorporates traumatic loading as a more realistic mode contributing to the progression of osteoarthritis (OA) compared to surgically transected models.
Killian
Megan L
ML
Soft Tissue Mechanics Laboratory, Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931, USA.
Isaac
Daniel I
DI
Haut
Roger C
RC
Déjardin
Loic M
LM
Leetun
Darin
D
Donahue
Tammy L Haut
TL
D000818:Animals; D000070598:Anterior Cruciate Ligament Injuries; D004195:Disease Models, Animal; D005269:Femur / Q000293:injuries / Q000473:pathology; D008592:Menisci, Tibial / Q000473:pathology*; D010003:Osteoarthritis / Q000150:complications / Q000473:pathology / Q000601:surgery*; D011817:Rabbits; D012422:Rupture, Spontaneous / Q000209:etiology; D013977:Tibia / Q000293:injuries / Q000473:pathology; D000070600:Tibial Meniscus Injuries; D016474:Weight-Bearing