Ischiofemoral Ligament Research Articles

Microscopic analysis of the iliofemoral and ischiofemoral ligaments in the hip joint: collagen fiber direction and crimp distribution

Since no previous studies have described the functional significance of the iliofemoral and ischiofemoral ligaments on the basis of microscopic analyses, we examined the direction of collagen fiber alignment and crimp distribution of the collagen fibers in sections cut in different directions. Polarized microscopic images of sections along the longitudinal (L) and transverse (T) planes of each ligament were obtained from 20 cadavers (8 males and 12 females, age at death 81.7 ± 9.4 years old). Results showed that the microscopic direction of collagen fibers in the iliofemoral ligament was parallel to the macroscopic direction, suggesting that this ligament may play a part in restricting extension of the hip joint. In contrast, the microscopic direction of collagen fibers in the ischiofemoral ligament was not parallel to the macroscopic direction, suggesting that this ligament may contribute not only to the restriction of medial rotation but also retstriction of flexion of the hip joint. From the low density of the crimp distribution in the L plane, the iliofemoral ligament may contribute to stability of the hip joint in the standing position in the living body. In conclusion, the microscopic observations of the direction of collagen fibers as well as the crimp distribution shown in the present study provide a better understanding of the functional significance of the iliofemoral and ischiofemoral ligaments.

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

To use computer navigation software to investigate the specific origins of the hip capsuloligamentous complex. 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. 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). 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 IV anatomic cadaveric study. See the guidelines online for a complete description of level of evidence.

An Anatomic Arthroscopic Description of the Hip Capsular Ligaments for the Hip Arthroscopist

To examine and describe the normal anatomic intra-articular locations of the hip capsular ligaments in the central and peripheral compartments of the hip joint. Eight paired fresh-frozen human cadaveric hips (mean age, 73.3 years) were carefully dissected free of soft tissue to expose the hip capsule. Needles were placed through the capsule along the macroscopic borders of the hip capsular ligaments. Arthroscopy was performed on each hip, and the relations of the needles, and thus the ligaments, to the arthroscopic portals and other soft-tissue and osseous landmarks in the hip were recorded by use of a clock-face reference system. The iliofemoral ligament (ILFL) ran from 12:45 to 3 o'clock. The ILFL was pierced by the anterolateral and anterior portals just within its lateral and medial borders, respectively. The pubofemoral ligament was located from the 3:30 to the 5:30 clock position; the lateral border was at the psoas-U perimeter, and the medial border was at the junction of the anteroinferior acetabulum and the cotyloid fossa. The ischiofemoral ligament (ISFL) ran from the 7:45 to the 10:30 clock position. The posterolateral portal pierced the ISFL just inside its superior/lateral border, and the inferior/lateral border was located at the posteroinferior acetabulum. In the peripheral compartment the lateral ILFL and superior/lateral ISFL borders were in proximity to the lateral synovial fold. The medial ILFL and lateral pubofemoral ligament borders were closely approximated to the medial synovial fold. The hip capsular ligaments have distinct and consistent arthroscopic locations within the hip joint and are associated with clearly identifiable landmarks in the central and peripheral compartments. The standard hip arthroscopy portals are closely related to the borders of the hip capsular ligaments. These findings will help orthopaedic surgeons know which structures are being addressed during arthroscopic surgery and may help in the development of future hip procedures.

Soft tissue injuries: 4 Hip and thigh

In this fourth paper in the Soft Tissue Injury series we cover aspects of soft tissue injury relating to the hip. Our understanding of injuries to the hip and thigh...

The Function of the Hip Capsular Ligaments: A Quantitative Report

Our purpose was to analyze the anatomy and quantitative contributions of the hip capsular ligaments. The stabilizing roles of the medial and lateral arms of the iliofemoral ligament, pubofemoral ligament, and ischiofemoral ligament were examined in 12 matched pairs of fresh-frozen cadaveric hips (6 male and 6 female hips). The motion at the hip joint was measured in internal and external rotation through ranges of motion from 30 degrees flexion to 10 degrees extension along a neutral swing path. The motion was standardized by use of frame stabilization and motion tracking. There is a clear and consistent ligamentous pattern within the hip corresponding to a distinct function and contribution to internal and external rotation. On releasing the ischiofemoral ligament, the greatest gain in range of motion was that of internal rotation. The largest increase of motion by releasing the pubofemoral ligament was observed in external rotation, especially during extension. The release of the medial and lateral arms of the iliofemoral ligament each gave the greatest increase of motion in external rotation, with the lateral arm release providing more range of motion in flexion and in a neutral position. The lateral arm release also showed a significant motion increase in internal rotation, primarily in extension. The ischiofemoral ligament controls internal rotation in flexion and extension. The lateral arm of the iliofemoral ligament has dual control of external rotation in flexion and both internal and external rotation in extension. The pubofemoral ligament controls external rotation in extension with contributions from the medial and lateral arms of the iliofemoral ligament. Together, these findings can have significant clinical applications. When abnormal muscular and osseous pathology can be eliminated as a cause of instability or restrictive range of motion, the understanding of the independent functions of the hip ligaments will aid in defining accurate assessment and nonsurgical and arthroscopic treatment techniques.

The mechanical properties of the human hip capsule ligaments

The human hip capsule is adapted to facilitate upright posture, joint stability, and ambulation, yet it routinely is excised in hip surgery without a full understanding of its mechanical contributions. The objective of this study was to provide information about the mechanical properties of the ligaments that form the hip capsule. Cadaver bone[ndash ]ligament[ndash ]bone specimens of the iliofemoral, ischiofemoral, and femoral arcuate ligaments were tested to failure in tension. The hip capsule was found to be an inhomogeneous structure and should be recognized as being composed of discrete constituent ligaments. The anterior ligaments, consisting of the 2 arms of the iliofemoral ligament, were much stronger than the posterior ischiofemoral ligament, withstanding greater force at failure and exhibiting greater stiffness. Knowledge of the anatomy and mechanical properties of the capsule may help the hip surgeon choose an appropriate surgical approach or repair strategy.

Traumatic dislocation of hip joint following low-velocity trauma, similarities to glenohumeral instability

Acute posterior hip dislocation following low velocity trauma in a young healthy adult is a rare injury. Almost 30 cases previously have been described in the literature. They are usually associated with prior trauma to the hip joint and will lead to recurrent instability after relocation. This injury is similar to shoulder instability: lesions and anomalies present in the hip joint with posterior instability are identical to the ones in the shoulder with instability. These are Bankart-like lesion of the posterior labrum, defect in ischiofemoral ligament similar to inferior glenohumeral ligament laxity of the shoulder, relative retroversion of femoral neck angle similar to loss of retroversion of the humeral neck and, finally, Pipkin type 1 fracture of the femoral head resembling a Hill-Sachs lesion of the humeral head. Successful treatment of this injury depends on addressing these pathologies. We present three cases of acute posterior hip dislocation in young adults after low-energy trauma, which presented to our unit over a 4-year period, and a review of another 21 cases of similar injury previously described in the literature. We will demonstrate these lesions and discuss the investigation and treatment modalities for posterior instability of the hip joint. We conclude that hip dislocation caused by low-energy trauma must be investigated and treated to avoid recurrence of dislocation and associated complications.

Regional material properties of the human hip joint capsule ligaments

The hip joint capsule functions to constrain translation between the femur and acetabulum while allowing rotational and planar movements. Despite the crucial role it plays in the pathogenesis of hip instability, little is known about its biomechanical properties. The goal of this study was to determine the regional material properties of the iliofemoral and ischiofemoral ligaments of the capsule. Ten human cadaveric specimens of each ligament were tested to failure in tension. The stress at failure, strain at failure, strain energy density at failure, toe- and linear-region elastic moduli, and the Poisson's ratio were measured for each ligament. The strain to failure was greatest in the ischiofemoral ligament, while no significant difference was noted in failure stress by region or ligament. The Young's moduli of elasticity ranged from 76.1 to 285.8 MPa among the different ligaments, and were generally consistent with properties previously reported for the shoulder capsule. The elastic moduli and strain energy density at failure differed by region. No significant differences in Poisson's ratio were found by region or ligament. The average Poisson's ratio was approximately 1.4, consistent with anisotropic behavior of ligamentous tissues. Understanding the material properties of the hip capsule may help the orthopaedic surgeon better understand normal ligament function, and thereby choose a surgical approach or strategy of repair. Furthermore, knowledge of the normal mechanical function of the hip capsule ligaments could assist in the evaluation of the success of a repair.

New aspects of the morphology and function of the human hip joint ligaments

The capsular ligaments of the human hip joint were submitted to exact morphological analysis, and they proved to be multiple and numerous. We have described various ligamentous systems and their interconnections, and have suggested new terminologies and systematics. The ligaments were subjected to functional analysis by means of measuring strips to determine the positions in which the ligaments are taut. The ligament systems were all found to serve a restrictive function, and various parts of the apparatus restricted all possible movements in the hip joint. Extension is restricted by the medial iliofemoral complex, abduction by the pubofemoral ligament, and adduction by the posterior coxal ligaments and by the superior ischiofemoral ligament. Flexion is restricted by the inferior ischiofemoral ligaments, inward rotation by the superior ischiofemoral ligament, and outward rotation by the lateral iliofemoral complex. Only the ligament of the femoral head is unable to exert a restricting function, despite reaching a state of tension in extreme adduction.