Paper #13 - ISHA Annual Scientific Meeting 2016

Anatomic Analysis of the Native Ligamentum Teres

Jacob D. Mikula, BS, Vail, CO UNITED STATES
Jorge Chahla, MD, Vail, CO UNITED STATES
Erik Slette, BA, Vail, CO UNITED STATES
Alex W. Brady, MSc, Vail, CO UNITED STATES
Cristiano Trindade, MD, Vail, CO UNITED STATES
Matthew T. Rasmussen, BS, Vail, CO UNITED STATES
Matthew Harris, MD, West Palm Beach, FL UNITED STATES
Robert F. LaPrade, MD, PhD, Vail, CO UNITED STATES
Marc J. Philippon, MD, Vail, CO UNITED STATES

Steadman Philippon Research Institute, Vail, CO, UNITED STATES

FDA Status Not Applicable

Summary: This study provides qualitative and quantitative anatomical descriptions of the ligamentum teres attachments and their relationship to arthroscopically pertinent bony structures on the acetabulum and femur.

Abstract:
Objectives: While many studies have emerged in recent years addressing the function of the ligamentum teres (LT) and providing descriptions of LT reconstruction techniques, its anatomy remains relatively undocumented, with a paucity of quantitative data describing LT’s origin at the acetabulum and insertion in the fovea capitis. As arthroscopic treatment of LT pathologies gains acceptance among surgeons, a clear understanding of the LT’s anatomy is needed. Therefore, the purpose of this study was to provide a qualitative and quantitative anatomic description of the LT attachments and relate its attachments to arthroscopically pertinent landmarks on the acetabulum and femur. Methods: Ten human cadaveric pelvises, complete with femurs, (mean age: 59.6, range 47-65) were dissected free of all extra-articular soft tissues to allow for isolation of the LT and its acetabular and femoral attachments. A 3-D coordinate measuring device (7315 Romer Absolute Arm) was used to quantify the attachment areas and their relationships to pertinent arthroscopic landmarks on both the acetabulum and femur. All anatomic landmarks were related using means [95% Confidence Interval, lower limit, upper limit] and anatomic directions. The clock-face reference system was used to describe acetabular anatomy for increased application to arthroscopic procedures. Results: The LT had a broad acetabular origin with six distinct anchoring points: pubic attachment, ischial attachment, iliac attachment, anterior attachment, posterior attachment, and transverse attachment. Superficially, the LT blended with the transverse acetabular ligament along its entire length (25.0 mm [95% CI, 22.9, 27.0). Beneath the transverse attachment, two substantial bands acted to anchor the LT to the ischial and pubic sides of the acetabular notch. The anterior attachment was substantially larger, and had a mean cross-sectional attachment area of 79.4 mm2 [95% CI, 53.8, 105.0], and was located at a mean clock-face position of 4:53 o’clock [95% CI, 4.45, 5.02]. The smaller posterior attachment and had a mean cross-sectional attachment area of 54.5 mm2 [95% CI, 53.8, 105.0], and was located at a mean clock-face position of 6:33 o’clock [95% CI, 6:23, 6:43]. Superior to these landmarks, there were three attachments to each of the three bones that converge within the cotyloid fossa (ilium, ischium, and pubis). The ischial attachment possessed the largest cross-sectional attachment area (127.3 mm2 [95% CI, 103.0, 151.7]) out of all of the LT’s acetabular attachments, followed closely by the iliac attachment (124.2 mm2 [95% CI, 93.31, 155.15]), located at a mean location of 1:49 o’clock [95% CI, 1:04, 2:34]. Finally, a smaller attachment was located on the pubic aspect of the acetabulum and often split into two separate bands (n = 8) located at 3:50 o’clock [95% CI, 3:41, 4:00] and 4:10 o’clock [95% CI, 4:02, 4:19] . As the LT coursed distally towards the femoral head, there was a confluence of its fibers to a single location within the anterosuperior region of the fovea capitis (Figure 2). The femoral attachment of the LT was an oval shape and had a mean area of 84.40 mm2 [95% CI, 64.90, 103.90], which comprised approximately 43.38% [95% CI, 37.76, 48.99] of the fovea capitis. Conclusion: The most important finding of this study was that the LT consistently had six anchoring points on the acetabulum and one anchoring point on the femur in all specimens. The qualitative and quantitative descriptions of the LT can be used to arthroscopically identify the LT’s attachments and guide arthroscopic surgical interventions.