不同固定表面生物型人工膝关节假体的骨长入实验研究

The bone ingrowth study of prostheses with different biological fixation surfaces in total knee arthroplasty

目的比较人工膝关节不同孔径的固定表面生物型假体植入兔体内的骨长入情况,为人工膝关节生物学固定方法的改进提供理论依据。方法自行设计制作兔部分限制型人工全膝关节表面置换假体,股骨髁和胫骨平台假体固定表面用激光焊接两层不锈钢网,一组设计为两层不锈钢网孔大小相同,网孔均为(2×2)mm,称大孔假体(实验组假体)。另一组设计为两层不锈钢网孔大小不同,大网孔大小为(2×2)mm,小网孔大小为(1.5×1.5)mm,大网孔钢网焊接在紧贴假体固定表面,小网孔叠放在其外面,称小孔假体(对照组假体)。两组假体两层钢网均错开焊接。30只成年新西兰大白兔随机分成两组,每组15只,分别行左侧人工膝关节置换术,髌骨不置换。术后1、3、6个月处死动物取材,每个时间点各5只,进行硬组织切片染色,计算假体骨界面新生骨形成率,假体与骨界面的骨结合率。结果假体骨界面新生骨形成率,假体与骨界面的骨结合率,实验组大于对照组(P<0.05)。结论生物型人工膝关节假体的固定表面孔径不同影响假体与骨界面的骨长入,大孔假体骨界面新生骨形成率及假体与骨界面的骨结合率要优于小孔假体。

Objective To compare the bone ingrowth of different mesh surface prostheses for total knee arthroplasty in rabbit, and to offer the morphology evidence to improve the biological fixation of prosthesis for total knee arthroplasty. Methods The partially restrained prostheses of total knee arthroplasty were designed personally. The basic shape of the prostheses consisted of femur condyle and tibia plateau that were welded with the extended stem by laser. The articular surface was polished smoothly. There were two species of double-layer mesh prostheses： the controlled prosthesis consisted of two layers with different pore size（ 1.5 mmx 1.5 mm at outer layer and 2 mmx 2 mm at inner layer） , known as micro-pore prosthesis ; the experimental prosthesis consisted of two layers with the same pore size （2 mmx 2 mm ）, known as macro-pore prosthesis. Both of the prostheses were 0. 25 mm per layer in thickness and the meshes were welded with the basic surface of the prostheses by laser. 30 New Zealand rabbits were divided randomly into two groups（ 15 for each group） and underwent left total knee arthroplasty using different prothesis respectively. The patella was reserved. There were five animals of each group at each time spot. The rabbits were sacrificed and the femur and tibia （including the knee prosthesis） were evaluated by histomorphometry in 1st, 3rd and 6th month postoperatively. The rate of new bone formation and the rate of osseointegration were calculated. Results The formation rate of new bone and the integration rate of bone and prosthesis interface in the experiment group were higher those that in control group （ P 〈 0. 05 ） in 1 st month , 3rd and 6th month postoperatively. Conclusions Differencnt surfaces of mesh prostheses alignment style may affect the effectiveness of bone ingrowth. The effect of the macro-pore prosthesis was better than that of the micro prosthesis.