2021 ISAKOS Biennial Congress ePoster
The Effect That Ligamentum Teres Deficiency Has On The Central Compartment Suction Seal Of The Hip: A Biomechanical Evaluation
Ian Al'khafaji, MD, Richmond, VIC AUSTRALIA
Yvonne Olszewski, BS, MS, Melbourne, Victoria AUSTRALIA
Edward Settle, BS, MS, Melbourne, Victoria AUSTRALIA
Georgina Clarnette, BS, MS, Melbourne, Victoria AUSTRALIA
Lukas Ernstbrunner SWITZERLAND
John M. O'Donnell, MBBS, FRACS, FAOrthA, Hawthorn, VIC AUSTRALIA
David Auckland, PhD, Melbourne, Victoria AUSTRALIA
University of Melbourne, Melbourne , Victoria , AUSTRALIA
FDA Status Not Applicable
Summary
The native hip suction seal is decreased in a ligamentum teres deficient state compared to an intact control
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Abstract
Introduction
In present literature, the function of the ligamentum teres (LT) is not well understood. It has been established, however, that the suction seal of the hip plays an important role in normal biomechanics. Anatomically, the hip is not a congruent joint due to the fact the cotyloid fossa does not directly articulate with the femoral head. Given the fact that the LT occupies the cotyloid fossa, it is theorized that the LT is critical in maintaining a normal suction seal. This cadaveric study evaluated the changes of the biomechanical suction seal in LT deficient hips compared to intact controls.
Methods
Six fresh-frozen unpaired human cadaveric hips were analyzed for average peak distraction force (APDF), average stiffness (AS), and average total energy (ATE) when distracting the hips to the point of breaking the seal. This was performed in the native intact LT state and a deficient LT state. Each specimen was examined in 20° of flexion, neutral, and 10° of extension. Statistical analysis was conducted through a t-test.
Results
In the neutral position, the deficient state displayed a significant decrease in APDF (33.20 N:83.32 N, p>.001), AS (63.72 N/mm:211.31 N/mm, p=.016), and ATE (82.34:151.79, p=.022) compared to the intact control. In extension, the deficient state exhibited a significant decrease in APDF (73.40 N:30.58 N, p>.001) and ATE (81.87:154.72, p=.007) compared to the intact control. There was no significant different in AS between the deficient and intact state in extension (104.50 N/mm:170.69 N/mm, p=.13). In flexion, the deficient state displayed a significant decrease in APDF (46.63 N:123.63 N, p=.003). No significant difference was exhibited in AS (157.13 N/mm:238.67 N/mm, p=.251) and ATE (120.87:205:93, p=.079) for the deficient versus intact state respectively.
Conclusion
Deficiency of the LT in the hip leads to a decreased biomechanical suction seal compared to an intact LT state. This loss of suction seal is most prominent when the hip is in neutral and extension. The LT plays a less prominent role of maintaining suction seal when the hip is in flexion.