[Inclusion of AMIS surgical approach in the Methods Used for Total Hip Arthroplasty: Learning Curve, Risks, Surgical Technique].

Abstract

Purpose of the study: The study aims to point out the risks and matters associated with the inclusion of a new anterior approach in total hip replacement methods and to determine when and whether the values of investigated parameters would come close to those of the established surgical technique. Another aim was to compare the blood loss in AMIS and DLA approaches.

Material and methods: The study covers 62 total hip arthroplasties in a breakdown by surgical approach. It investigated the progress of the entire surgical team - surgeon's learning curve, time curve of preparation for surgery, placement of the acetabular component, blood loss, and postoperative haemoglobin drop. The control group consisted of patients in whom the established surgical technique, i.e. the direct lateral approach, was used. The component placement was assessed on standard centered AP view radiographs of the operated joint by using the ellipse method to calculate the Liaw's anteversion and inclination.

Results: A total of 62 surgeries were included in the study. The AMIS group (31 surgical procedures) was composed of 19 women and 12 men, with the mean age of 70 years. The preparation of the operating field took 11.5 minutes on average and the duration of surgery from incision to suture was 66 minutes. The blood loss reached 295 ml, with the mean Hb drop of 16 g/l. The mean anteversion and inclination were 22° and 43°, respectively. The DLA group (31 surgical procedures) was composed of 14 women and 17 men, with the mean age of 67.5 years. The preparation of the operating field took 8 minutes on average and the duration of surgery from incision to suture was 53 minutes. The blood loss reached 300 ml, with the mean Hb drop of 21 g/l. The mean anteversion and inclination were 17° and 43°, respectively. The duration of the 1st to 10th AMIS surgeries was 80 minutes; the duration of the 11th to 20th surgeries was 58 minutes; and in the case of the 21st to 31st surgeries it was 55 minutes.

Conclusions: The results showed that there is no need to worry about an excessively long learning curve of the surgeon and the entire team when introducing a new surgical procedure as long as they have a positive attitude thereto. The data obtained in other countries reveal that the AMIS approach is on the rise ever more often. The authors therefore hope that this study will contribute to its widespread adoption.