Fluoroscopic Categorization of Cementless Acetabular Component Positioning.

Area of Science:

• Orthopedic surgery
• Medical imaging
• Biomedical engineering

Background:

• Accurate measurement of the angle of lateral opening (ALO) is crucial in hip arthroplasty.
• Existing methods for intraoperative ALO assessment can be complex or imprecise.
• The BioMedtrix BFX acetabular component features a recess that projects as an ellipse at varying ALO values.

Purpose of the Study:

• To evaluate a novel fluoroscopic method for categorizing ALO.
• To determine the association between actual ALO and categorization based on a visible elliptical recess.
• To assess the feasibility of using fluoroscopy for intraoperative ALO estimation.

Main Methods:

• A custom jig with an inclinometer and a BFX acetabular component was used.
• Fluoroscopic reference images were acquired at 35, 45, and 55 degrees ALO with 10 degrees retroversion.
• A blinded observer categorized 30 randomized fluoroscopic images based on the visible elliptical recess.

Main Results:

• The fluoroscopic categorization method demonstrated perfect agreement (30/30) with actual ALO values.
• A weighted kappa coefficient of 1 indicated flawless concordance.
• The method proved highly reliable in distinguishing between different ALO categories.

Conclusions:

• The evaluated fluoroscopic method accurately categorizes the angle of lateral opening (ALO).
• This technique offers a simple and effective approach for estimating intraoperative ALO.
• The findings support the clinical utility of this fluoroscopic method in hip arthroplasty procedures.