Total hip arthroplasty: Direct anterior approach in the supine position provides more accurate component positions

The retrospective analysis of 76 total hip arthroplasty cases compared the fluoroscopy-guided direct anterior approach in the supine position (S-DAA) with the lateral decubitus position (L-DAA). Results suggested that in the supine group, the DAA provided more accurate positioning of the femoral and acetabular components. However, the study showed no significant difference between the two groups at follow-up in hip joint function and activity.

Total hip arthroplasty (THA) is one of the most reliable and successful orthopaedic procedures, and there is a continuous increase in the demand for THA given its success and improved quality of life for patients, where the accurate placement of the acetabular component is both difficult and important to achieve.

Accurate positioning of the acetabular component in THA can reduce the occurrence of postoperative complications, such as slowing the wear of the polyethene liner, increasing the stability of the hip joint, reducing the risk of prosthesis loosening and the difference in bilateral leg length. This implies the importance of the position of femoral and acetabular components for wear resistance and stability.

Weifeng Ji, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province, China, and colleagues set out to determine whether the fluoroscopy-guided direct anterior approach in the supine position is more helpful in improving the position of femoral and acetabular components than the fluoroscopy-guided direct anterior approach in the lateral decubitus position.

For this purpose, the researchers performed a retrospective analysis of 76 cases of fluoroscopy-guided DAA total hip arthroplasty (38 cases in the S-DAA and 38 cases in the L-DAA group) in one hospital from 2019 to 2021. They analyzed differences in anteversion, inclination, global offset (GO), femoral offset (FO), and leg length discrepancy (LLD) measurements during and after surgery. The postoperative FO, GO, LLD, and postoperative and preoperative Harris hip scores were compared between the groups.

The researchers reported the following findings:

· In the S-DAA group, there were no significant differences in the mean intraoperative inclination angle anteversion angle, FO, GO, and LLD compared to the postoperative values,

· In the L-DAA group, there were significant differences between the intraoperative and postoperative measurements.

· There were significant differences in the accuracy of LLD, FO, and GO between the two groups.

· Compared with the L-DAA group, the average differences of inclination, anteversion, LLD, FO, and GO during and after operation in the S-DAA group were smaller, and the consistency was higher.

· There was a significant difference in Harris hip score between the two groups one week after surgery.

· There was no significant difference in Harris hip score between 1 month and three months after surgery.

"The findings showed DAA in the supine position to be more accurate for positioning the prosthesis than the DAA in the lateral position under fluoroscopy," the researchers wrote.

"In the follow-up, we found no significant difference in the range of motion and function of the hip joint, and the quality of life improved in both patients in the lateral position and patients in the supine position after total hip arthroplasty with DAA.

Reference:

Chen, P., Liu, W., Wu, C. et al. Fluoroscopy-guided direct anterior approach total hip arthroplasty provides more accurate component positions in the supine position than in the lateral position. BMC Musculoskelet Disord 24, 884 (2023). https://doi.org/10.1186/s12891-023-07014-4