To observe the histology change of the insertion using different diamertrical bone tunnel in anterior cruciate l igament (ACL) reconstruction. Methods Ninety Japanese rabbits were selected, wihout female and male l imit, weighing 2.5-3.0 kg, and were randomly divided into 3 groups, 30 in each group. The ratio of transplantation l igament diameter and bone tunnel diameter was 1/1 (group A), the ratio was 1/1.5 (group B), and the ratio was 1/2 (group C). Bone tunnel observation and histology observation were carried out in the 4th, 8th and 16th weeks postoperat ively. Results Wound healed well in 3 groups. The mean time of walking functional recovery was 1.5, 2.0 and 3.5 days in groups A, B and C respectively. After 4 weeks of operation, more soft tissues at tunnel entry were observed in group A and group B than in group C; after 8 weeks of operation, there was no crevice at bone-tunnel entry of the groups A and B, there was no improvement in group C; after 16 weeks of operation, groups A and B showed the normal insertion, group C had no normal insertion. Histology observation: in groups A, B and C, bone-tunnel was filled with loose connective tissue after 4 weeks of operation; group A and group B emerged the discontinuation ACL insertion tidal l ine after 8 weeks of operation, group C had no insertion; groups A and B emerged the similarity normal ACL insertion tidal l ine structure after 16 weeks of operation, but group C had no this structure. The results of ultimate tensile strength in groups A, B and C were (75.44 ± 7.06), (91.37 ± 6.14) and (126.91 ± 4.61) N respectively at 4 weeks; the results were (74.31 ± 4.81), (88.30 ± 7.46) and (124.34±8.44) N respectively at 8 weeks; and the results were (62.20 ± 5.32), (71.53 ± 5.99) and (83.62 ± 5.69) N respectively at 16 weeks. There was no significant difference between group A and group B (P gt; 0.05), and there were significant differences between groups A, B and group C (P lt; 0.05). Conclusion In the ACL reconstruction, the ratioof transplantation l igament diameter and bone tunnel diameter being 1/1.5 will not affect the insertion outcome, but if theratio less than the l imit it will affect the insertion outcome.
ObjectivesTo systematically review the influence for catheter mechanical dysfunction of different peritoneal dialysis catheterization methods.MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and VIP databases were searched to collect randomized controlled trials (RCTs) and cohort studies on comparisons of different peritoneal dialysis catheterization from inception to March 31st, 2018. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies. Network meta-analysis was then performed by using ADDIS 1.16.6 software.ResultsA total of 33 studies (9 RCTs and 24 cohort studies) involving 3 301 patients were included. Network meta-analysis showed that the incidence of catheter mechanical dysfunctionwas the least and had statistically significant difference compared with that in percutaneous catheterization (OR=3.60; 95%CI, 1.64 and 15.38) and open surgery catheterization (OR=5.86; 95%CI, 2.68 and 14.53). Percutaneous catheterization was superior to open surgery catheterization, but there was no significant difference.ConclusionsLaparoscopic catheterization may be the best technique for catheter insertion in peritoneal dialysis considering catheter dysfunction. Each technology has its own advantages. Choice of insertion method should be based on the characteristics of both the patient and the insertion techniques.
In unicompartmental replacement surgery, there are a wide variety of commercially available unicompartmental prostheses, and the consistency of the contact surface between the common liner and the femoral prosthesis could impact the stress distribution in the knee after replacement in different ways. Medial tibial plateau fracture and liner dislocation are two common forms of failure after unicompartmental replacement. One of the reasons is the mismatch in the mounting position of the unicompartmental prosthesis in the knee joint, which may lead to failure. Therefore, this paper focuses on the influence of the shape of the contact surface between the liner and the femoral prosthesis and the mounting position of the unicompartmental prosthesis on the stress distribution in the knee joint after replacement. Firstly, a finite element model of the normal human knee joint was established, and the validity of the model was verified by both stress and displacement. Secondly, two different shapes of padded knee prosthesis models (type A and type B) were developed to simulate and analyze the stress distribution in the knee joint under single-leg stance with five internal or external rotation mounting positions of the two pads. The results showed that under a 1 kN axial load, the peak contact pressure of the liner, the peak ACL equivalent force, and the peak contact pressure of the lateral meniscus were smaller for type A than for type B. The liner displacement, peak contact pressure of the liner, peak tibial equivalent force, and peak ACL equivalent force were the smallest for type A at 3° of internal rotation in all five internal or external rotation mounting positions. For unicompartmental replacement, it is recommended that the choice of type A or type B liner for prosthetic internal rotation up to 6° should be combined with other factors of the patient for comprehensive analysis. In conclusion, the results of this paper may reduce the risk of liner dislocation and medial tibial plateau fracture after unicompartmental replacement, providing a biomechanical reference for unicompartmental prosthesis design.