[Comparative study on differences in acetabular position during total hip arthroplasty between by direct anterior...

To compare the differences in acetabular position during total hip arthroplasty (THA) between by direct anterior approach and by posterolateral approach.

Between December 2008 and December 2015, 102 patients undergoing THA were included in the study. THA was performed by anterior approach in 51 cases (anterior group) and by posterolateral approach in 51 cases (posterolateral group). There was no significant difference in gender, age, body mass index, side, and cause of illness between 2 groups ( P>0.05), with comparability. The acetabular abduction angle and anteversion angel were measured on the X-ray film at 1 day after operation to evaluate whether the acetabular prosthesis was displaced in the safe zone.

The acetabular abduction angle was (42.28±5.77)° in the anterior group and was (43.93±7.44)° in the posterolateral group, showing no significant difference ( t=1.30, P=0.19). The acetabular anteversion angle was (21.14±5.17)° in the anterior group and was (21.05±4.10)° in the posterolateral group, showing no significant difference ( t=0.05, P=0.96). The ratio in the target safe zone of the acetabular abduction angle in the anterior group and the posterolateral group were 88.2% (45/51) and 84.3% (43/51) respectively, showing no significant difference ( χ²=0.33, P=0.56). The ratio in the target safe zone of the acetabular anteversion was 80.4% (41/51) in the anterior group and was 82.4% (42/51) in the posterolateral group, showing no significant difference between 2 groups ( χ²=0.06, P=0.79). The ratio in the target safe zone of both the abduction and anteversion angel was 70.6% (36/51) in the anterior group and was 68.6% (35/51) in the posterolateral group, showing no significant difference ( χ²=0.05, P=0.82).

There is no differences in the acetabulum position during THA between by direct anterior approach and posterolateral approach.