Clinical Orthopaedics and Related Research®

, Volume 473, Issue 2, pp 602–607 | Cite as

Femoroacetabular Impingement Negates the Acetabular Labral Seal During Pivoting Maneuvers but Not Gait

  • Maureen K. DwyerEmail author
  • Hugh L. Jones
  • Richard E. Field
  • Joseph C. McCarthy
  • Philip C. Noble
Symposium: 2014 Hip Society Proceedings



Experimental disruption of the labrum has been shown to compromise its sealing function and alter cartilage lubrication. However, it is not known whether pathological changes to the labrum secondary to femoroacetabular impingement (FAI) have a similar impact on labral function.


Does damage to the labrum occurring in association with abnormal femoral morphology affect the labral seal?


Using 10 fresh cadaveric specimens (mean age 50 years, ± 8), we measured the capacity of the central compartment of the hip (the iliofemoral joint) to maintain a seal during fluid infusion, which may help elucidate the function of the labrum during weightbearing. Specimens with and without abnormal femoral morphology (six normal-appearing specimens and four whose geometry suggested cam-type FAI) were tested in postures observed during functional activities, including simulations of normal gait, stooping, and pivoting. Each specimen with FAI morphology exhibited secondary damage of the labrum and the adjacent chondral surface, whereas specimens of normal morphology were undamaged.


Average peak central compartment pressure was reduced during pivoting for specimens with the presence of labral damage secondary to FAI. When placed in pivoting positions, hips with FAI maintained lower fluid pressures within the central compartment compared with intact specimens (15 ± 3 versus 42 ± 8 kPa, respectively; effect size: 1.08 [−0.36 to 2.31]; p = 0.007). No differences in peak pressure were observed between groups (FAI versus normal) for postures simulating either gait (21 ± 6 versus 22 ± 4 kPa; p = 0.902) or stooping (9 ± 2 versus 8 ± 3 kPa; p = 0.775) with the numbers available.


The acetabular seal, quantified by the maximum intraarticular pressure, was reduced during pivoting; however, the seal was maintained during simulated gait and stooping.

Clinical Relevance

Because degeneration is progressive with repetitive impingement, loss of the labral seal starts to be seen during pivoting and may progress from there, but in this small-sample cadaver study that evaluated specimens in middle adulthood, the seal remains intact during simulated gait and stooping. Our study suggests that labral damage secondary to cam-type FAI may reduce the ability of the labral to provide an adequate seal of the central compartment of the hip during loading; however, the extent to which this is affected requires further investigation.


Femoral Head Central Compartment Joint Position Peripheral Compartment Femoroacetabular Impingement 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We acknowledge Mr Michael Hogen, Mr Stephen Wallace, and Mr Andrew Moorman for their assistance with data collection and specimen dissection; Mr Jerry Alexander for his assistance in acquiring specimens; and Mr Sabir Ismaily for his assistance with capturing the motion analysis data.


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Copyright information

© The Association of Bone and Joint Surgeons® 2014

Authors and Affiliations

  • Maureen K. Dwyer
    • 1
    • 2
    Email author
  • Hugh L. Jones
    • 3
  • Richard E. Field
    • 4
  • Joseph C. McCarthy
    • 1
    • 2
  • Philip C. Noble
    • 3
    • 5
  1. 1.Department of OrthopaedicsMassachusetts General HospitalBostonUSA
  2. 2.Kaplan Joint CenterNewton-Wellesley HospitalNewtonUSA
  3. 3.The Institute of Orthopedic Research and EducationHoustonUSA
  4. 4.St Anthony’s HospitalSurreyUK
  5. 5.Baylor College of MedicineHoustonUSA

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