Defining the Origins of the Iliofemoral, Ischiofemoral, and Pubofemoral Ligaments of the Hip Capsuloligamentous Complex Utilizing Computer Navigation

Abstract

Purpose To use computer navigation software to investigate the specific origins of the hip capsuloligamentous complex. Methods Six fresh frozen cadaver hips were anatomically landmarked utilizing a three-dimensional computer navigation system. The acetabular origins of the iliofemoral, pubofemoral, and ischiofemoral ligaments were statically digitized. Computer software was used to create a 180° (6:00) meridian line positioned over the midpoint of the acetabular notch, and to present the results in a clocklike manner in hours and minutes (00:00) and also degrees relative to the 12 o'clock position. Results The iliofemoral ligament origin starts at 17° (±31°) from the 12 o'clock position, or 12:35 (±1:02) in hours and minutes, and ends at 69° (±13°) or 2:18 (±0:25), spanning a mean distance of 52° (±19°). The ischiofemoral ligament has the broadest origin, starting at 262° (±12°) or 8:44 (±0:24), and ending at 353° (±17°) or 11:45 (±0:14), spanning a mean distance of 90° (±6°). The pubofemoral ligament origin is the smallest, starting at 121° (±5°) or 4:02 (±0:11), and ending at 163° (±9°) or 5:27 (±0:18), spanning a mean distance of 42° (±5°). The iliofemoral ligament origin demonstrates the greatest anatomic variability with regards to its location and its size ( p = 0.002). Conclusion This study demonstrates that there is significant variability in the size and location of the iliofemoral ligament origin versus the pubofemoral and ischiofemoral ligaments. Level of Evidence Level IV anatomic cadaveric study. See the guidelines online for a complete description of level of evidence.