Adamczyk Mark J, Odell Tim, Oka Richard, Mahar Andrew T, Pring Maya E, Lalonde François D, Wenger Dennis R
Akron Children's Hospital, Akron, OH, USA.
J Pediatr Orthop. 2007 Apr-May;27(3):314-8. doi: 10.1097/BPO.0b013e318034038f.
The purpose of this study was to compare the biomechanical stability of triple innominate osteotomies fixed with either bioabsorbable or stainless steel screws. Triple innominate osteotomies were performed on composite hemipelves and fixed with either three 4.5-mm bioabsorbable screws or three stainless steel 4.5-mm screws. Two screws were placed from the iliac wing into the acetabular fragment, and 1 screw was placed from below the acetabular fragment into the iliac wing. Eight specimens for each screw type were biomechanically tested in an anatomical position (replicating weight bearing) and in a flexed and abducted position (replicating spica cast positioning). Specimens were cyclically loaded between 10 and 450 N to simulate the hip contact force in this population. Lower screws were then removed, and specimens were tested under identical conditions. Fragment displacement (mm) and construct stiffness (N/mm) were compared with a 2-way analysis of variance (P < 0.05). There were no significant differences between materials for fragment displacement or construct stiffness. Anatomical position showed significantly less displacement than spica position for both materials. Initial displacement in the spica position was significantly less during lower loads for stainless steel fixation. Bioabsorbable screws demonstrate comparable biomechanical stability to stainless steel screws in anatomical and spica positions at physiological loads. Flexion and abduction of the femur adversely affect the stability of the construct for both materials. Bioabsorbable screws behave similarly to steel screws when stabilizing triple innominate osteotomies and would have the advantage of not requiring a second surgery for screw removal. Confirmation of biocompatibility should be completed before widespread clinical application.
本研究的目的是比较使用生物可吸收螺钉或不锈钢螺钉固定的三联无名骨截骨术的生物力学稳定性。对复合半骨盆进行三联无名骨截骨术，并用3枚4.5毫米生物可吸收螺钉或3枚4.5毫米不锈钢螺钉进行固定。2枚螺钉从髂骨翼置入髋臼碎片，1枚螺钉从髋臼碎片下方置入髂骨翼。每种螺钉类型的8个标本在解剖位置（模拟负重）和屈曲外展位置（模拟髋人字石膏固定位置）进行生物力学测试。标本在10至450牛之间循环加载，以模拟该人群中的髋关节接触力。然后取出下方的螺钉，在相同条件下对标本进行测试。采用双向方差分析比较碎片位移（毫米）和结构刚度（牛/毫米）（P<0.05）。两种材料在碎片位移或结构刚度方面无显著差异。两种材料在解剖位置的位移均显著小于髋人字石膏固定位置。在较低负荷下，不锈钢固定在髋人字石膏固定位置的初始位移显著较小。在生理负荷下，生物可吸收螺钉在解剖位置和髋人字石膏固定位置的生物力学稳定性与不锈钢螺钉相当。股骨的屈曲和外展对两种材料的结构稳定性均有不利影响。在稳定三联无名骨截骨术时，生物可吸收螺钉的表现与钢螺钉相似，且具有无需二次手术取出螺钉的优势。在广泛临床应用之前，应完成生物相容性的确认。
