Objective To investigate and compare the difference between two implants of reconstructing anterior cruciate l igament (ACL) for the early heal ing of implants tunnel interface in terms of biological mechanism. Methods Fiftyfive adult New Zealand rabbits weighing 2.0-2.8 kg were selected. Patellar l igament with tibia-bone block was obtained fromthe left knee joint serving as donor site, right knee joint served as the recipient site of autograft for ACL reconstruction. Thebone block end of implant was bone-bone interface heal ing model, while the l igament end was tendon-bone interface heal ing model. The general condition of rabbits was observed after operation, the gross observation and histology observation were conducted at 2, 4 and 8 weeks after operation (n=5), and biomechanics examination was conducted at 4 and 8 weeks after operation (n=20). Results Rabbits behaved normally after operation. The gross observation indicated that ACL had complete continuity and moderate tension during experiment. Histology observation: most part of bone-bone interface was connected by fibrous tissue, while the tendon-bone interface was mainly filled by granulation tissue 2 weeks after operation; most part of bone-bone interface was bone union, and there were osteogenesis reaction and large quantity of fibroblasts in the tendonbone interface 4 weeks after operation; complete bone union was evident in bone-bone interface, and the appearance of Sharpey fibers and the formation of indirect insertion occured in part of tendon-bone interface 8 weeks after operation. Biomechanics observation: the pull-out rate for tendon-bone interface and bone-bone interface 4 weeks after operation was 85% and 15%, respectively; while it was 95% and 5% 8 weeks after operation, respectively; indicating there was a significant difference between two groups (P lt; 0.001). Conclusion In the early stage after ACL reconstruction, bone-bone interface is better than tendonbone interface in terms of intensity and speed of heal ing.
Objective To study the operative procedure and effect of arthroscopic reconstruction of both anterior cruciate l igament (ACL) and posterior cruciate l igament (PCL) with anterior tibial is tendon allograft. Methods From February 2005 to July 2006, 10 cases of both ACL and PCL rupture were reconstructed with anterior tibial is tendon allograft, including 7 men and 3 women, aging 18-45 years with an average of 30.2 years. The locations were left knee in 6 cases and right knee in 4 cases. All of them had identified trauma history. The disease course was about 1-3 weeks (mean 1.8 weeks). Both ACLand PCL were reconstructed under arthroscope with allograft anterior tibial is tendon of 26-28 cm in length and immobil ization with extention position brace was given for 4 weeks after operation. The active flex knee exercise was done from 0-90° at 4 weeks and more than 90° at 6 weeks. Results All operations were finished successfully, there were no blood vessel and nerve injury. The operative time was 90-110 minutes (mean 100 minutes). The wound healed by first intention and no early compl ication occurred. Ten cases were followed up for 12 months to 15 months with an average of 13.5 months. Thier gait was normal, knee activity degree was 0-135°. The anterior drawing tests and media and lateral stress tests were negative after operation in 10 cases; and the posterior drawing tests were negative in 8 cases and 2 cases was at grade I. Hydra arthrosis of knee occurred in 2 cases and was cured after remove of fluid and injection of sodium hyaluronate. The Lysholm knee function score was increases from 24.89 ± 5.39 before operation to 96.00 ± 4.59 at 12 months after operation, showing significant difference (P lt; 0.05). Conclusion Arthroscopic reconstruction of both ACL and PCL with anterior tibial is tendon allograft has the advantages of short operation time, less compl ications and good cl inical effects.