[Effects of the cementing technique on cementing results concerning the coxal end of the femur].

The purpose of this study was to determine the influence of jet-lavage and cement pressurising techniques upon cement penetration into proximal femoral cancellous bone. In a cadaver study 60 left human cadaver femora were used for implantation of cemented stem components. Four different groups of cementing techniques were generated, the allocation to the groups was randomized. Bone lavage was carried out either using jet-lavage or manual syringe lavage, cement application differed with regard to the amount of pressurisation used. Five different stem designs were used. Radiographs were taken and horizontal sections were obtained at predefined levels (2 cm) using a diamond saw. Microradiographs were taken and analysed using image analysis to assess cement penetration into cancellous bone. In an additional study the influence of jet-lavage (1000 ml) versus syringe lavage (1000 ml) was studied in 11 paired human cadaver femora. The specimens were imbedded in specially designed pots. Bone cement was applied in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3000 N. The analysis protocol was identical to the main experiment. Both jet-lavage and pressurisation of bone cement significantly improved the penetration of cement into cancellous bone (p = 0.027 and p = 0.003, respectively). In the presence of strong, dense cancellous bone the findings were more pronounced. In the additional comparative study cement intrusion was significantly better (p < 0.001) in the jet-lavage group. We did not observe an influence of the stem type upon outcome (penetration). The use of jet-lavage yields significantly improved cement penetration and should be regarded mandatory in cemented total hip arthroplasty. High pressurising techniques are effective means to improve the interdigitation between cancellous bone and cement, but should only be administered in combination with jet-lavage to reduce the risk of thrombo-embolic complications.