| Objectives To evaluate the biomechanical strength at the femoral site in anterior cruciate ligament(ACL) reconstruction with Cortical press-fit bolt(CPB). Investigate the turnover of histology in ACL reconstruction with CPB. Observe the clinical outcome of the application of CPB in ACL reconstruction. Methods 8 swine fresh frozen knee specimens were used. All specimens were rearmed at room temperature (28℃) for 24 hours. An ACL reconstruction was performed on each specimens, using four-stranded hamstring tendon graft. At femoral site, every four-stranded hamstring tendon graft was fixed with Cortical press-fit bolt. On each sample, a load-to-failure test was performed. Ultimate failure load, stiffness, displacement of 100N, displacement of 400N, and mode of failure were recorded respectively. Animal models of the ACL reconstruction in 24 healthy F/M New Zealand White rabbits (2-3 months old) were made using extensor digitorum longus tendon and randomly divided into 2 groups-experimental group(CPB) and Control group. The animals were killed at 4,8,12 weeks each after operation for histological and X-ray examination. The specimens were stained with Hematoxylin-Eosin method to observe the pathology changes of the graft.7 patients underwent arthroscopic ACL reconstruction procedures between Jan,2010 and Apr,2010. There were 6 males and 1 female who were 30 years old for average. All the patients were accepted the Rolimeter measurement and X-ray examination at pre-operation,3 days and 1 month post-operation. Results Test showed the average maximum load,100N displacement,400N displacement and stiffness in Cortical press-fit bolt group were 418±50N,6±2mm,15±6mm, 41±10N/mm respectively. All the statistical data have no statistical difference between cortical press-fit bolt fixtion and bioabsorbable interference screw fixtion (P>0.05). The histology results showed good healing in tendon-bone, tendon-CPB and bone-CPB site. All patients received the Rolimeter test and X-ray examination. The statistic data of the test pre-operation and post-operation at 3 days and 1 month were performed by Newman-Keuls method. The result showed that there were significant difference between pre-operation and post-operation of tibial movement(p≤0.01), and no significant difference between 3 days and 1 month post-operation(P>0.05). Conclusions The biomechanical strength at the femoral site fixation with Cortical press-fit bolt is similar to Bioabsorbable interference screw, and can meet physiological demand. Cortical press-fit blot can improve the tendon-bone healing after ACL reconstruction in rabbits. It's a good choice to use the cortical press-fit blot in ACL reconstruction.
|
PDF Full Text Request