Comparison of short-term curative effects between three fixations of the tibial end in reconstruction of the anterior cruciate ligament / 中华创伤骨科杂志

Objective:To compare the short-term curative effects between 3 fixations of the tibial end with an interface screw, an interface screw + a portal nail and an interface screw + a knotless rivet in reconstruction of the anterior cruciate ligament (ACL).Methods:A retrospective study was conducted to analyze the data of 150 patients who had undergone reconstruction surgery for ACL injury at Department of Orthopaedics, Jinling Clinical Medical College, Nanjing Medical University from January 2019 to December 2021. The patients were divided into 3 groups according to their different fixations of the tibial end. In group A of 51 cases subjected to fixation of the tibial end with an interface screw, there were 40 males and 11 females with a mean age of (29.8±10.6) years. In group B of 55 cases whose tibial end was fixated with an interface screw + a portal nail, there were 47 males and 8 females with a mean age of (28.6±6.9) years. In group C of 44 cases whose tibial end was fixated with an interface screw + a knotless rivet, there were 39 males and 5 females with a mean age of (28.6±8.1) years. The 3 groups were compared in terms of International Knee Documentation Committee (IKDC) scoring and Lysholm knee function scoring at 12 and 48 weeks after operation, incidence of local pain at 4 weeks after operation, and stability of the knee at 48 weeks after operation.Results:There was no significant difference in the preoperative general data or follow-up time between the 3 groups, indicating comparability ( P>0.05). At 12 weeks after surgery, in Group B and Group C, the IKDC scores [(74.27±3.32) and (76.48±3.83) points] and Lysholm knee joint scores [(77.65±3.14) and (79.75±5.39) points] were significantly better than those in Group A [(69.73±6.04) and (71.63±3.36) points] ( P<0.05). However, there was no statistically significant difference in the above scores among the 3 groups at 48 weeks after surgery ( P>0.05). The incidence of local pain at the tibial end in group B (9.1%, 5/55) was significantly higher than that in group A (0, 0/51) and group C (2.3%, 1/44) at 4 weeks after surgery, and the results of the anterior drawer test in group A (36 negative cases, 14 cases of grade Ⅰ, and 1 case of grade Ⅱ) were significantly worse than those in group B (50 negative cases, and 5 cases of grade Ⅰ) and group C (40 negative cases, and 4 cases of grade Ⅰ) at 48 weeks after surgery ( P<0.05). Conclusions:In ACL reconstruction, all the 3 fixations of the tibial end can achieve fine short-term curative effects. Fixation with an interface screw + a knotless rivet may lead to a lower rate of ligament relaxation and a higher score of early knee function than fixation with an interface screw, and a lower incidence of local pain at the tibial end than fixation with an interface screw + a portal nail.

Effects of polydopamine-coated porous titanium alloy scaffolds loaded with zoledronic acid-gelatin nanoparticles for topical sustained drug release on osteoclasts: an in vitro study / 中华创伤骨科杂志

Objective:To analyze the effects of a novel type of polydopamine (PDA)-coated porous titanium alloy scaffolds loaded with zoledronic acid-gelatin nanoparticles (ZOL-GNPs) for topical sustained drug release on osteoclasts in vitro. Methods:After porous titanium alloy scaffolds were fabricated using electron beam melting technique and ZOL-GNPs with different ZOL concentrations (0, 1, 10, 50, 100, 500 μmol/L) were prepared by desolvation method, PDA-coated porous titanium alloy scaffolds loaded with ZOL-GNPs were constructed by combining the two. The characteristics of the scaffolds were analyzed. The biomechanics of 3 different scaffolds (bare porous titanium alloy scaffolds, PDA-coated porous titanium alloy scaffolds, and PDA-coated porous titanium alloy scaffolds loaded with ZOL-GNPs) were investigated. Drug release detection was carried out by high performance liquid chromatography on the 1st, 4th, 7th, 14th, 21st, and 28th days respectively. The osteoclasts were inoculated into the novel scaffolds with different ZOL concentrations. The expression of osteoclast-related genes was detected by real-time quantitative (RT)-polymerase chain reaction (PCR); the expression of osteoclast-related proteins was detected by Western-blot.Results:The PDA-coated porous titanium alloy scaffolds loaded with ZOL-GNPs were successfully constructed. Electron microscope scanning showed that the GNPs were well spheroidized, smooth in surface, and uniformly dispersed, with a particle size of (243.6±63.4) nm. The ZOL-GNPs were uniformly compounded on the surface and in the pores of the scaffolds, and the spheres were regular in shape with no adhesion. The biomechanical experiments showed that the elastic moduli of the porous titanium alloy scaffolds under 3 different conditions were (1.81±0.12) GPa, (1.80±0.23) GPa and (1.81±0.15) GPa, showing no significant difference ( P> 0.05). The drug release percentage in the porous titanium alloy scaffolds was obviously high on the first day, and increased gradually and slowly in the subsequent 27 days. In the scaffolds with a low concentration ZOL, more osteoclasts adhered and proliferated; in the 50 μmol/L scaffolds, spheroid cells appeared; the spheroid cells increased and even apoptosis occurred with an increase in the ZOL concentration. RT-PCR showed that the expression of Ctsk gene and TRAP gene increased with the increased ZOL concentration, peaked in the 50 μmol/L scaffolds, and then decreased with the increased concentration, showing statistically significant differences ( P < 0.05). Western-blot showed that the expression pattern of Ctsk and TRAP was similar to that of their related genes. Conclusions:The novel PDA-coated porous titanium alloy scaffolds loaded with ZOL-GNPs demonstrate good mechanical properties and an anti-osteoporosis effect via their topical sustained drug release. The scaffolds with a ZOL concentration of 50 μmol/L may exert the best effect on inhibition of osteoclasts.

Analysis of Plantar Pressure before and after Occurrence of Neurogenic Intermittent Claudication in Patients with Central Lumbar Spinal Stenosis / 医用生物力学

Objective To investigate the changes of plantar pressure distributions and risk of falling before and after the occurrence of neurogenic intermittent claudication (NIC) in patients with central lumbar spinal stenosis (LSS), so as to provide theoretical and data references for the application of plantar pressure analysis in judgment of walking abilities for LSS patients. Methods Twelve patients with LSS at the L4-5 segment were selected as the LSS group, while twelve healthy adults at the same age were selected as the control group. Footscansystem was used to measure plantar pressure of these subjects during walking. Contact area percentage of the total foot contact area (CA%), pressure-time integral (PTI), foot progression angle (FPA), contact time percentage of the stance time (CT%) and total stance time (CT) in both LSS group and control group were compared to evaluate changes of plantar pressures during walking．Results Before the occurrence of NIC, compared with the control group, the LSS group had lower CT% during the forefoot push-off phase (FFPOP) and higher CT% during the initial contact phase (ICP), the total CT and FPA also increased, and the PTI of the 1st-3rd metatarsals and the CA% of the 2nd and 3rd metatarsals were higher. After the NIC occurred, for LSS group, CT% during ICP and forefoot contact phase (FFCP) decreased, CT% during the foot flat phase (FFP) and FFPOP as well as total CT and FPA increased, the PTI and CA% increased in 1st-4th metatarsals. Moreover, the CA% also increased in toe zone, both the PTI and CA% decreased in heel zone. Conclusions In patients with central LSS during walking, the distribution of plantar pressure shifts forward, with abnormal phase of the stance time occurring. Such abnormality will be further aggravated by NIC, indicating a higher risk of falling.

The Ability and Helplessness of the Surgeon / 中国医学伦理学

With the development of science and technology and the progress of society, the application of a se-ries of new theories, new technologies and new materials makes surgeons' skills improve. But due to the limitations of technological development, public cognition and regulations construction, current surgeons have a variety of helplessness and still face many problems that need to be solved urgently. The solution of these problems needs not only the perfection and progress of the surgeons, but also the understanding and inclusion of the society as well as the perfection and implementation of the policies and regulations. Only with the cooperation of all sides, it can give full play to surgeon' s ability, reduce the surgeon' s helplessness, make the doctor-patient relationship more har-monious, and promote the healthy development of medical and health services.

Mandibular movement characteristics in patients with skeletal class Ⅲ malocclusion during chewing movement / 实用口腔医学杂志

Objective: To investigate mandibular movement characteristics in patients with skeletal class Ⅲ malocclusion during chewing different foods. Methods: 14 skeletal class Ⅲ adult patients with mandibular asymmetry, 10 patients without mandibular asymmetry and 10 normal control cases were chosen to find out the different condylar and incisor movement area ratio based on the aid of ARCUSdigma mandibular moving track analysis system. Results: First,during chewing soft food, the condylar tracing length of skeletal class Ⅲ adult patients with mandibular asymmetry were significant different in sagittal and horizontal plane compared with the other two groups(P<0.05), while the incisor point trajectory difference was not statistically significant. Second, the condylar and incisor movement characteristic showed much more different among three samples during chewing brittle food(P<0.05). Third, in sagittal plane, the deflective condylar movement area ratio was significantly higher than that of the other two groups during chewing hand food(P<0.01). Conclusion: The mandibular movement in skeletal class Ⅲ adult patients are affected obviously by the shape and texture of food. Asymmetric lower mandible patients have a greater preponderance of this phenomenon.