1994, 9(2):67-77. DOI: 10.3871/j.1004-7220.1994.2.77.
Abstract:Six post mortem specimens of the knee joint were studied for the measurement of contact pressure on the tibial plateaus.Transistor pressure transducers and Bourdon tube pressure gauges were used for this purpose.At an extended position of the knee joint with the intact menisci,the peak pressure increased up to on the cartilage covered by the meniscus did not reach to 2.0 MPa,except on near the free margin of the meniscus.After excision of 30% of the meniscus and total meniscectomy,the peak contact pressures showed 5.6 and 76 MPa respectively under the load of 2700N.
1994, 9(2):78-83. DOI: 10.3871/j.1004-7220.1994.2.83.
Abstract:It is the first time in literature that the PPC signal was proved in vivo in this study to be originated from friction between the articular surfaces of the patellofemoral joint.Seventeen patients(17 knee joints) of knee injuries whose joints were inspected by arthroscopy and 24 patients(36 knee joints) of degenerative osteoarthritis(OA) to whom total knee replacement was peformed were included in this study.physiological patellar crepitus(PPC) signals which were obtained preoperatively were compared with the operative findings of the knee joint.Five young and five old normal volunteers were also included for age controlled comparison.Normal PPC signals occurred throughout the whole cycle of knee flexion and extension in the individual with intact patellofemoral articular cartilage.The mean root mean square(RMS) of the PPC signal which represents the amplitude and energy content of the vibration waves of the normal young individuals was 67.3 mv and 48.9 mv for the normal old individual s.The mean RMS for those knee injury patients whose patellofemoral joints were intact was 46.0 mv and for the OA patients was 18.4 mv.The mean RMS value for the latter was significantly smaller than the others(P<0.001).For OA patients,three types of PPC signals can be identified.Each represents a unique pattern of degeneravive involvement of the knee joint.PPC measurement is a simple non-invasive diagnostic technique for evaluating the integrity of articular cartilage of the patellofemoral joint.Not only the severity of pathology but also the area of involvement in the knee joint can be assessed.There is a geat future for PPC to be used clinically.
1994, 9(2):84-89. DOI: 10.3871/j.1004-7220.1994.2.89.
Abstract:The authors designed a new internal fixator for scoliosis---multi-screw fixed distractor-compressor via the vertebral pedicle.The new device has strong forces of fixation,distraction,compression and anti-rotation.It can produce free movememt in three-different levels and fix the vertebral column in three-dimensions.Its anti-rotaion ability is 34-46 per cent higher than that of Harrington-Luque rods,and is 35-48 per cent higher than that of two Luque rods.Its anti-lateral bend ability is 130-141 per cent higher than that of Harrington-Luque rods,and is 130-145 per cent higher than that of two Luque rods(P<0.001).
1994, 9(2):90-93. DOI: 10.3871/j.1004-7220.1994.2.93.
Abstract:Traditionally only the transmission of the radial displacement wave used to be emphasized in the theories that analyse the transmission of the pulse wave in the elastic tube.To understand the behavior of the axial displacement wave in the elastic tube,especially,in the arteries,this context analysing the transmission of the axial displacement wave in the elastic tube,and comparison being made with the radial displacement wave in wave velocity and wave damping in the physiologic range,and in quantities describing the effect of these waves on the cardiovascular system.The result shows that,on most conditions and in most arteries,the axial displacement wave exerts much less influence on the cardiovascular system than the radial displacement wave,so it can be omitted;but on some special conditions,the axial displacememt wave is as important as the radial displacement wave.
1994, 9(2):94-98. DOI: 10.3871/j.1004-7220.1994.2.98.
Abstract:The purpose of this study is to confirm the effect of Eriqeron Breviscvps(EB), a Chinese medicinal herb, to speed up orthodontic tooth movement by means of biomechanic analysis. Ten cases, who had labioversion malposition of upper canines and had their upper first premolars extracted, were selected in this study. The upper canines and first molars of all cases had been placed standard orthodontic appliances which could force the canines to move distally. The gauze connected with positive electrode were touched at gingival area of the canines with right side infiltrated with solution of, EB and left side with distilled water served as control. The ion-introduction was performed every other week with direct current of 0.2mA and testing over 20min every time.The results showed there were significant differences in biomechanics of canines movement between two sides, with average velocity, acceleration and periodontal resistance in right canines being 0.168(mm/day),3.42×10-3(mm/day2)and 82. 60(g),and in control side being 0.099(mm/day),1.91×10-3(mm/day2)and 109.36(g).The study observed the mechanical characteristics of canines' movement which could quantitatively and scientifically prove that EB iontophoresis had a high ability to reconstruct periodontal tissues during the orthodontic tooth movement, which would lay the experimental foundation for applying EB into clinial practice.
1994, 9(2):99-102. DOI: 10.3871/j.1004-7220.1994.2.102.
Abstract:The influence of electro-acupuncture Neiguan point at different time on circadian rhythms of systolic time intervals of normal young male adults were studied in this work. It was found that the indices of STI of normal young male adults were all shown approximate circadian rhythms. The acrophase and significant level of rhythms could be changed by electro-acupuncture at Neiguan point, but the period of rhythms kept constant. The results show that the time factor plays an important role in the effects of acupuncture or electro-acupuncture. So acupuncture may be looked on as a chronizer and applied to modulate some rhythms.