An In Vivo Comparison of the Orientation of the Transverse Acetabular Ligament and the Acetabulum

Abstract

Aligning the acetabular component with the Transverse Acetabular Ligament (TAL) to ensure optimal anteversion has been reported to reduce dislocation rates. However, to our knowledge in vivo measurement of the TAL angle has not yet been reported in a large cohort of normal hips. CT scans of 218 normal hips were analyzed. The TAL and four acetabular rim anteversion angles were measured (superiorly to inferiorly) relative to the anterior pelvic plane. The mean TAL anteversion angle was 20.5° ± 7.0°, and the acetabular rim angles from superior to inferior were 11.0° ± 12.9°, 19.9° ± 8.8°, 20.9° ± 6.2° and 25.1° ± 6.2° respectively. Both the TAL and the acetabular rim were significantly more anteverted in females than in males. The TAL anteversion angle was comparable to the predominant orientation (central rim section) of the native acetabulum while the superior acetabulum was comparatively retroverted and the inferior was relatively more anteverted.

Preoperative Evaluation of Transverse Acetabular Ligament Orientation using CT for Total Hip Arthroplasty

“…We evaluated the operative anteversion of TAL preoperatively using 3D-CT. The average angle of the TAL and variations corresponded to previously reported anatomical, intraoperative, and image evaluation of the TAL [8,9,12,15,20,21]. These findings suggest that our instrumentation using 3D-CT can achieve accurate measured values.…”

“…Archbold et al reported that the transverse acetabular ligament (TAL) and acetabular labrum were useful for determining the anteversion of the acetabular component [7]. TAL has been evaluated as an anatomic landmark for acetabular component orientation [7][8][9][10][11][12][13][14][15][16][17]. The usefulness of TAL as a landmark is still controversial.…”

Three-Dimensional Templating for Acetabular Component Alignment During Total Hip Arthroplasty

“…The research questions examine previously reviewed crite- Studies suggest that the rate of dislocation can be reduced to 0.6% by using the TAL as a reference for acetabular cup alignment. 21,22 The position of the cup was also determined to be anteverted, aligned, or retroverted to the native TAL. Using the software, 2 lines were created from the center of the cup to the acetabular edge to form a reference for assigning clock values to (1) where the cup was within bone, (2) where the cup was not inside the bone (Figure 2), and (3) where the lateral most aspect of the acetabulum was.…”

Three Dimensional Architecture of the Acetabular Transverse Ligament and its Connection with the Acetabular Labrum

“…However, the acetabular transverse ligament is considered to be a factor that limits femoral head reduction in the developmental dislocation of the hip, and its excision and resection release the acetabular entrance, rendering the femoral head easier to reduce to the acetabulum (9,10). The acetabular transverse ligament is easy to visualize, even in the joints with arthritic changes; thus, it is clinically useful (e.g., as an indicator of acetabular component placement in total hip arthroplasty) (11)(12)(13). Ligaments usually connect to bones; however, the transverse ligament also connects to the anterior and posterior angles of the acetabulum.…”