ObjectiveTo study the effectiveness of internal tension-relieving technique for arthroscopic assisted anterior cruciate ligament (ACL) reconstruction. MethodsBetween March 2011 and September 2014, 51 cases of complete ACL rupture were randomly divided into 2 groups. Arthroscopic assisted single-bundle ACL reconstruction combined with internal tension-relieving technique was performed in 26 cases (group A), arthroscopic assisted single-bundle ACL reconstruction in 25 cases (group B). There was no significant difference in gender, age, cause of injury, injured side, body mass index, Outerbridge classification of articular cartilage injury, disease duration, and the preoperative International Knee Documentation Committee (IKDC) score, Lysholm score, and KT-1000 test value between 2 groups (P>0.05). At 3, 6, and 12 months after operation, the KT-1000 was used to measure the anterior stability, and IKDC and Lysholm scores to evaluate the function of knee joint. ResultsHealing of incision by first intention was obtained in all patients of 2 groups, without complications of infection, deep vein thrombosis of lower extremity, and blood vessels and nerves injury. The patients were followed up 12 months after operation. All patients received second microscopic examination. The reconstructed ACL had good continuity and good coverage of synovial tissue. There was no re-rupture in any cases. The range of motion of the knee joint was close to normal. The MRI showed good healing of the ligament and the bone tunnel at 12 months after operation. KT-1000 test value, IKDC score, and Lysholm score at 3, 6, and 12 months after operation were significantly improved when compared with preoperative ones (P<0.05), but no significant difference was found among different time points after operation (P>0.05). There was no significant difference in IKDC score and Lysholm score between 2 groups at 3 and 12 months (P>0.05); but IKDC score and Lysholm score of group A were significantly higher than those of group B (P<0.05) at 6 months. At diffenent time points after operation, the KT-1000 test values of group A were significantly lower than those of group B (P<0.05) except the value at 3 months (P>0.05). ConclusionFor patients with ACL rupture, using internal tension-relieving technique can effectively alleviate tension force of reconstructed ligament, which is beneficial to the healing of reconstructed ligament and early rehabilitation of the knee joint.
ObjectiveTo explore a method of three-dimensional (3D) printing technology for preparation of personalized rat brain tissue cavity scaffolds so as to lay the foundation for the repair of traumatic brain injury (TBI) with tissue engineered customized cavity scaffolds. MethodsFive male Sprague Dawley rats[weighing (300±10) g] were induced to TBI models by electric controlled cortical impactor. Mimics software was used to reconstruct the surface profile of the damaged cavity based on the MRI data, computer aided design to construct the internal structure. Then collagen-chitosan composite was prepared for 3D bioprinter of bionic brain cavity scaffold. ResultsMRI scans showed the changes of brain tissue injury in the injured side, and the position of the cavity was limited to the right side of the rat brain cortex. The 3D model of personalized cavity containing the internal structure was successfully constructed, and cavity scaffolds were prepared by 3D printing technology. The external contour of cavity scaffolds was similar to that of the injured zone in the rat TBI; the inner positive crossing structure arranged in order, and the pore connectivity was good. ConclusionCombined with 3D reconstruction based on MRI data, the appearance of cavity scaffolds by 3D printing technology is similar to that of injured cavity of rat brain tissue, and internal positive cross structure can simulate the topological structure of the extracellular matrix, and printing materials are collagen-chitosan complexes having good biocompatibility, so it will provide a new method for customized cavity scaffolds to repair brain tissue cavity after TBI.