Smartphone Application Helps Improve the Accuracy of Cup Placement by Young, Less-Experienced Surgeons during Primary Total Hip Arthroplasty.

Background Dislocation after total hip arthroplasty (THA) partly under the surgeon's control, by appropriate placement of the components. We aimed in this study to determine the accuracy of using intra-operative smartphone applications (Apps) to place the acetabular cup within the safe abduction angle by less experienced surgeons during THA surgery when compared to the conventional freehand technique for cup placement. Methods Sixty primary THAs were performed, 30 using the conventional freehand technique (control group) and 30 using the smartphone app technique (study group) to determine the acetabular cup abduction angle by the same young surgeon with less than one year of experience. Postoperative mean cup abduction angle, mean cup anteversion angle, and the percentage of cups within the safe abduction zone as measured on radiographs were compared between the two groups. Results In the study group, the mean cup abduction angle was significantly lower (P=0.0008), and the acetabular cup was placed within the safe zone in a significantly higher (P<0.001) percentage of patients (93% vs 63%) when compared to the control group. However, there was no significant difference (P=0.40) between the two groups when the mean cup anteversion angle was compared. Conclusion The smartphone app technique may help achieve an accurate acetabular cup abduction angle and a higher percentage of cups placed within the safe zone of abduction by a less experienced surgeon when compared to the conventional freehand technique. Using tools such as the smartphone app to measure the acetabular cup position can reduce intraoperative errors by young and less experienced surgeons during THA surgery.