Structural Properties of the Native Ligamentum Teres.

Background: A majority of studies investigating the role of the ligamentum teres (LT) have focused primarily on anatomical and histological descriptions. To date, however, the structural properties of the LT have yet to be fully elucidated.

Purpose: To investigate the structural properties of the native LT in a human cadaveric model.

Study Design: Descriptive laboratory study.

Methods: A total of 12 human cadaveric hemipelvises (mean age, 53.6 years; range, 34-63 years) were dissected free of all extra-articular soft tissues to isolate the LT and its acetabular and femoral attachments. A dynamic tensile testing machine distracted each femur in line with the fibers of the LT at a displacement-controlled rate of 0.5 mm/s. The anatomic dimensions, structural properties, and modes of failure were recorded.

Results: The LT achieved a mean yield load of 75 N and ultimate failure load of 204 N. The LT had mean lengths of 38.0 and 53.0 mm at its yield and failure points, respectively. The most common (75% of specimens) mechanism of failure was tearing at the fovea capitis. On average, the LT had a linear stiffness of 16 N/mm and elastic modulus of 9.24 MPa. The mean initial length and cross-sectional area were 32 mm and 59 mm(2), respectively.

Conclusion: The human LT had a mean ultimate failure load of 204 N. Therefore, the results of this investigation, combined with recent biomechanical and outcomes studies, suggest that special consideration should be given to preserving the structural and corresponding biomechanical integrity of the LT during surgical intervention.

Clinical Relevance: The LT may be more important as a static stabilizer of the hip joint than previously recognized. Further studies are recommended to investigate the appropriate indications to perform surgical repair or reconstruction of the LT for preservation of hip stability and function.