Graft healing after anterior cruciate ligament reconstruction in rabbits.
Anterior cruciate ligament reconstruction with patellar tendon was performed in 50 rabbits (two groups of 25 animals) by the outside-in (Group I) and the inside-out (Group II) techniques. Five animals from each group were sacrificed at different times (2 weeks, 1, 3, 6, and 9 months). Histologic analysis showed that the intraarticular part of the graft was morphologically similar to a normal ligament in both groups at 9 months. In Group 1, a newly formed bone-graft junction along the tunnel walls was observed inside the femoral tunnel. At 6 months, this junction resembled a direct type junction. The old bone-tendon junction showed an early disappearance of the fibrocartilage and was differentiated as a direct junction only at 9 months. In Group 2, at the site of the old bone-tendon junction a fibrocartilaginous layer was present during the whole process of remodeling, and at 6 months this area resembled a direct junction. These observations would suggest that when the junction is placed inside the tunnel (outside-in technique) the process of remodeling is more dramatic and slower than when it is placed at the intraarticular exit of the tunnel (inside-out technique), probably because of the formation of a new bone-graft junction along the tunnel walls that partially unload the old junction.
Panni
A S
AS
Department of Orthopaedics, Catholic University, Rome, Italy.
Milano
G
G
Lucania
L
L
Fabbriciani
C
C
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology / Q000601:surgery*; D016723:Bone Remodeling; D001863:Bone Screws; D001864:Bone Wires; D002113:Calcification, Physiologic; D002358:Cartilage, Articular / Q000473:pathology; D002454:Cell Differentiation; D002455:Cell Division; D019902:Chondrocytes / Q000473:pathology; D003238:Connective Tissue / Q000473:pathology; D005260:Female; D005269:Femur / Q000473:pathology / Q000601:surgery; D005500:Follow-Up Studies; D010020:Osteonecrosis / Q000473:pathology; D010026:Osteosclerosis / Q000473:pathology; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods; D010329:Patella / Q000473:pathology / Q000601:surgery; D017847:Patellar Ligament / Q000637:transplantation*; D011817:Rabbits; D013314:Stress, Mechanical; D013977:Tibia / Q000473:pathology / Q000601:surgery; D014182:Transplantation, Autologous; D014945:Wound Healing