ABSTRACT
Objective: To assess the influence of absorbable poly-D, L-lactide acid (PDLLA) rods on the development of epiphyseal plate after implanted into the distal femoral epiphysis in skeletally immature New Zealand white rabbits. Methods: Seventy-five New Zealand white rabbits were evenly randomized into 3 groups according to the diameter of rods: 1.5 mm PDLLA rod group, 2.2 mm PDLLA rod group, and 3.2 mm PDLLA rod group. The absorbable PDLLA rods were placed into a drill hole of equal size in the intercondylar portion of the right femur, crossing the central portion of epiphyseal plate; empty drill holes of same size were made across the left femoral physis, which served as a control. The area of injured epiphyseal plates was calculated before operation. The animals were sacrificed at 3, 6, 9, 12 and 24 weeks after operation. Measurement of femur bone length, radiographic measurement of both knee joint valgus angles, histology sections and transmission electron microscopic examination of the physis and adjacent bones were performed to evaluate the influence of implanted rods on epiphyseal plate. Results: The proportions of injured area caused by the drill holes in 1.5 mm group, 2. 2 mm group, and 3.2 mm group were (1.86±0.10)%, (4.03±0.52)% and (7.52±1.02)%, respectively. At 24 weeks after operation, femur bone lengths (mm) of experimental and control sides were 90.60±0.55 and 90.27±0.84 in 1.5 mm group,87.53±0.67 and 87.06±0.78 in 2.2 mm group, and 85.30±1.39 and 84.91±1.40 in 3.2 mm groups, respectively; their knee joint valgus angles (°) were 7.863±1.26 and 8.110±1.18 in 1.5 mm group, 8.858±1.30 and 9.453±1.95 in 2.2 mm group, and 11.90±2.80 and 14.448±5.17 in 3.2 mm group, respectively. There was no significant difference in femur lengths and valgus angles between 2 sides in each group (P>0.05). Both femur bone lengths in 3.2mm group were shorter than those in the 1.5 mm and 2.2 mm groups. No abnormalities of cartilage cells were observed, without obvious histological evidence of inflammation; only nonspecific foreign body reaction and macrophage infiltration were noticed. Conclusion: PDLLA rod itself does not cause any disturbance to the development of the epiphyseal plate. The growth disturbance of epiphyseal plate depends on the area of injured epiphyseal plate; a injured area over 7% of epiphyseal plate may cause the growth disturbance of epiphyseal plate.
ABSTRACT
Objective To discuss whether the separating block of sensory nerve with acupoint-injection and epidural analgesia by ropivacaine during labour.Methods Ninty full term primigravidae with ASAⅠ～Ⅱwere randomly divided into 3 groups:group E(n = 30),group C(n = 30)and group A(n = 30).When the external cervi- cal os was dilated to 3cm,group A:acupiont-injection to Ci Liao;group E:epidural analgesia with 0.075% ropiva- caine and fentanyel 2?g/ml;group C:combining group A and group E except fentanyel 2?g/ml.Level of pain(VAS scores),degree of sensory and motor block,the mode of delivery,the progress of labour and side effects were recorded and compared.Results The level of pain(VAS scores)in group A was higher than that of group C and group E,and there were no significant differences in group C and group E,Bur there were some side effects discovered in group E. There was no significant differences of the mode of delivery in the groups.Conclusion The method that acupoint- rejection combined with epidural analgesia by 0.075% ropivacaine is effective and has no side effects for labour.