[Quality of tibial cementing in total knee arthroplasty: one or two phase cementing of the tibial and femoral implants].

Purpose Of The Study: When implanting a total knee prosthesis, the tibial component can be cemented either independently in the flexion position by maintaining an axial force on the implant, or simultaneously in extension by applying a compression force on both the tibial and femoral implants after reducing the prosthesis. The purpose of this study was to determine whether the quality of the cementing depends on the method used: independently in the flexion position, or simultaneously in the extension position.

Material And Methods: This was a prospective comparative study between two groups of 20 patients assigned alternatively to one of two study arms: Group 2 with a tibial implant cemented independently and Group 1 with a tibial implant cemented simultaneously with the femoral implant. The cancellous surfaces were prepared by irrigation and gravity flow wash-out. Aspiration of the cancellous section surface was maintained until the radio-opaque cement with standard viscosity (CMW3) was inserted. The penetration of cement into the cancellous bone was noted by zone on the postoperative radiographs (seven days and one month). Implant position, presence of early lucent lines and cement debris were noted. Radiographs were taken under fluoroscopic guidance in order to obtain the best image of the joint space and the tibial plateau.

Results: Cement penetration into the tibial plateau was significantly more pronounced in Group 2 for zones 1, 2 (p<0.01) and 3 (p<0.05) on the above proof view. Early translucent lines were noted in 15 of 20 knees in Group 1 (p<0.01). Cement debris and microfractures were noted in five knees in Group 1 (one in Group 2). The position of the implants was not affected by the method used for cementing.

Conclusion: This study demonstrates the theoretical and radiographic interest of cementing the tibial piece independently with the knee in the flexion position for total knee replacement. It is important to apply sustained pressure to obtain good quality cement-bone interpenetration.