To compare the stability of the acetabulum prosthesis after using different methods of filing acetabulum to reconstruct acetabulum, find out more stable methods and provide reference for clinical application.

Complete 10 antiseptic pelvic specimens from the Anatomy Teaching and Research Section of West Anhui Health Vocational College were collected. The concentric circular sequence filing (CCSF), the concentric circular non-sequence filing (CCNSF), the non-concentric circular sequence filing(NCCSF) and the concentric circular non-sequence filing(NCCNSF) were used to file the acetabulum. Both sides of the pelvic acetabulums were sat on one block. On one side the acetabulum was filed using concentric circles to reconstruct acetabulum by two ways: the acetabulum was sequence filed, the prosthesis was pressed for trial and measured. Based on the sequence filing, the acetabulum was then non-sequence filed and measured again. On the other side the non-concentric circles filing was applied to reconstruct acetabulum, by which the acetabulum was sequence and non-sequence filed, and the prosthesis was pressed for trial again. Rotary torque resistance and pull-out capacity of the acetabulum prosthesis were measured. Four kinds of acetabulum filing methods were designed to be four different groups. Data were compared by variance analysis and SNK - q test.

In CCSF group, the pull-out capacity of the acetabulum prosthesis was (83.8±3.3)N, rotating torque resistance was(26.5±2.6) Nm In CCNSF group, the pull-out capacity was(93.6±2.2)N, rotating torque resistance was (34.8±2.2) Nm. In NCCSF group, the pull-out capacity was (69.2±2.9) N, rotating torque resistance was (12.1±2.6) Nm, while in NCCNSF group, the pull-out capacity was (75.3±2.2) N, and rotating torque resistance was (16.8±1.9) Nm. The differences in rotary torque resistance among the groups and the different blocks were statistically significant(F =443.8, 6.2, both P<0.05). SNK - q test showed the rotating torque resistance was non-equal between the four groups. The differences in axial pull-out capacity among the groups were statistically significant(F =187.2, P<0.05), while there was no-difference among the different blocks(F=1.9, P>0.05). SNK-q test showed the pull-out capacity complete no-equal. Pull-out capacity and rotary torque resistance presented as CCNSF>CCSF>NCCNSF>NCCSF.

In the pelvic specimen experiments, posterior hemispherical cup prosthesis is more stable in concentric circular reconstruction of acetabulum, the stability of prosthesis in the acetabulum fossa reconstructed by non-sequence filing is stronger. The concentric circular and non-sequence filing can increase prosthesis stability.