Mechanical analysis of femoral neck fracture fixation in synthetic bone

Acta Ortop Bras. 2014;22(3):155-8. doi: 10.1590/1413-78522014220300914.

Abstract

Objective: To analyze statistically results obtained between biomechanical assays on fixation of femoral neck fracture type Pauwels III, on synthetic bone, using 7.5 mm non parallel cannulated screws and control group.

Methods: Ten synthetic bones from a national brand were used. Test group: fixation of 70((o)) tilt femoral neck osteotomy was performed using three 7.5 mm non parallel cannulated screws. We analyzed the resistance of this fixation with 5 mm of displacement, and rotational deviation (phase 1) and with 10 mm offset (phase 2).

Control group: the models were tested in their integrity until the femoral neck fracture occurred.

Results: the values of the test group in phase 1, in sample 1-5 had a mean of 517N and SD = 96N. Rotational deviations showed a mean of 3.79° e SD = 2. 03°. In phase 2, mean was 649N and SD = 94N. The values of the maximum load in the control group were: 1544N, 1110N, 1359N, 1194N, 1437N; respectively. Statistical analysis between the groups showed a statistically significant lower value in the test group.

Conclusion: the analysis of mechanical resistance between the groups has determined statistically significant value for the test group.

Keywords: Biomechanical phenomenas; Femoral neck fractures; Fracture fixation, internal.