ePoster #303 - ISHA Annual Scientific Meeting 2016

Entheseal Insertion of the Iliofemoral Ligament and Its Relationship with Femoral and Acetabular Anatomy

Ricardo Goncalves Schroder, PT, Dallas, TX UNITED STATES
Robroy L. Martin, PhD, PT, CSCS, Pittsburgh, PA UNITED STATES
Anthony Khoury, MSc, Dallas, TX UNITED STATES
Juan Gomez Hoyos, MD, Medellin, ANTIOQUIA COLOMBIA
Ian James Palmer, PhD, Oklahoma City, OK UNITED STATES
Hal David Martin, DO, Dallas, TX UNITED STATES

Hip Preservation Center Hip Preservation Center at Baylor Scott&Withe Health System, Dallas, Texas, UNITED STATES

FDA Status Not Applicable

Summary: A number of studies have demonstrated the capsular ligaments as the primary stabilizers during rotational movements of the hip joint. The Iliofemoral ligament is anatomically and functionally divided into the medial and lateral arms as it crosses the anterior aspect of the joint. The present study aim to identify, measure and determine the relationship of variations of the femoroacetabular anatomy

Abstract:
Introduction
A number of studies have demonstrated the influence of capsular ligaments as the primary stabilizers during rotational movements of the hip joint. The ILFL is anatomically and functionally divided into the medial and lateral arms as it crosses the anterior aspect of the joint. According to the hip position, both arms have different functions stabilizing the femoral head during repetitive rotational and translational forces. The present study aims to (1) identify and measure width and length of the distinct entheseal femoral insertion of the medial and lateral arm of the (ILFL). (2) Establish a validated and reliable MRI technique to measure the entheseal of the Lateral Arm of the ILFL (LAILFLch), and (3) determine the relationship and differences of the LAILFLch between femoral and acetabular version (FV and AV).

Methods
107 human cadaveric femurs were investigated. A clay impression molds of the femoral insertion of the lateral and medial of the ILFL arm was utilized to measure width and length. 50 MRI of subjects who underwent to examination due to hip pain were separated into four groups: Decreased femoral version <20° (n= 74 hips), increased femoral version = 20°(n= 26), decreased acetabular version <20° (n=65), and increased acetabular version =20° (n=35). A consistent and reliable technique (ICC 0.89 and 0.94) to measure the LAILFLch was determined using axial MRI. FV, AV and LAILFLch were bilaterally measured. A statistical analysis determined the influence of FV and AV on the LAILFLch and the relationship of FV and AV with the LAILFLch.

Results
A distinct entheses were present for the medial and lateral arms of the ILFL in 93% (100/107) and 100% (107/107) of anatomical specimens, respectively. The medial and lateral entheses had the following values respectively: width 6.6 mm ± 3.4 and 10.4mm ± 2.4; and length 13.3 mm ± 6.2 and 17.7 mm ± 4.3. The decrease FV group had a significant increased LAILFLch in comparison to increased FV (p = 0.026), 4.40 ± 1.59 mm and 3.45 ± 1.97 mm respectively. The LAILFLch had no differences (p = 0.74) between increased AV 4.16 ±1.78 and decreased AV 4.22 ±1.77. FV displayed a moderate but significant relationship (R2 = -0.47; p = 0.005) in comparison to AV (R2 = -0.18; p = 0.08).

Conclusion
The medial and lateral arms of the iliofemoral ligament were identified as unique and separate entheseal attachments at the intertrochanteric knob and greater trochanteric crest. The MRI technique was a consistent and reliable method to measure the LAILFLch. Decreased FV increased LAILFLch in comparison to increased FV and variations of AV, suggesting a potential secondary osseous response to increased load on the lateral arm of the iliofemoral ligament. The present study defines the importance of proximal femoral anatomy for radiographic evaluation, treatment, and surgical planning of iliofemoral ligament repair or reconstruction.