Radiographic Identification of Arthroscopically Relevant Acetabular Structures

Area of Science:

• Orthopedic surgery
• Radiographic anatomy
• Hip arthroscopy

Background:

• Acetabular anatomy is well-documented, but standardized radiographic guidelines are lacking.
• This study establishes a radiographic map of acetabular landmarks in the hip.

Purpose of the Study:

• To quantify the precise radiographic locations of arthroscopic landmarks around the acetabulum.
• To test the hypothesis that these landmark locations are reproducible despite anatomical and positional variations.

Main Methods:

• Descriptive laboratory study involving ten fresh-frozen cadaveric specimens.
• Placement of radio-opaque hardware at key landmarks, followed by anteroposterior (AP) and false-profile radiography.
• Digital measurement of landmark positions and distances using a Picture Archiving and Communication System (PACS).

Main Results:

• On AP radiographs, rectus femoris heads were located proximally to the teardrop line, with specific distances noted for insertions and the anterior inferior iliac spine to the acetabular rim.
• False-profile views revealed mean distances between rectus femoris heads and between the anterior labral sulcus and transverse acetabular ligament.
• Landmarks were mapped to specific clockface positions on the acetabulum, with the transverse acetabular ligament midpoint at 7 o'clock.

Conclusions:

• Quantitative measurements confirmed the reliable radiographic locations of described surgical landmarks.
• Distances between landmarks and reference lines were reproducible on both AP and false-profile radiographs.
• Understanding these radiographic presentations can improve intraoperative portal and hardware placement, as well as preoperative and postoperative assessments in hip arthroscopy.