A novel positioner for accurately sitting the acetabular component: a retrospective comparative study

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Medical device development

Background:

• Hip replacement surgery aims to restore function by accurately reconstructing the hip's center of rotation (COR).
• Conventional methods can lead to inaccuracies in COR reconstruction, potentially affecting clinical outcomes.
• A novel positioner integrating preoperative planning and intraoperative guidance was developed to enhance COR reconstruction accuracy.

Purpose of the Study:

• To evaluate the efficacy of a new positioner in improving the accuracy of hip joint center of rotation (COR) reconstruction during total hip arthroplasty.
• To compare the radiological and clinical outcomes between patients who underwent hip replacement using the new positioner versus conventional methods.

Main Methods:

• A retrospective study comparing 32 patients (Group A) using the positioner with 40 patients (Group B) using conventional techniques.
• Collection and analysis of radiological parameters (COR height, horizontal displacement, cup inclination, and anteversion) and clinical measurements (Harris Hip Score) preoperatively and at follow-up.

Main Results:

• The positioner group (A) achieved a reconstructed COR significantly closer to the anatomic COR in height (0.19 mm vs. 3.45 mm vertical dislocation, P < 0.005).
• Group A demonstrated improved accuracy in cup inclination (42.14° ± 3.57° vs. 38.73° ± 7.65°, P = 0.015).
• All cups in Group A were radiologically stable, with higher mean postoperative Harris Hip Scores in both groups.

Conclusions:

• The developed positioner enables more precise restoration of the COR position in hip replacement surgery.
• Satisfactory short-term radiological and clinical outcomes were observed with the use of the positioner.
• Further research is recommended for complex cases before widespread adoption.