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. 2015 Jul;2(2):175-83.
doi: 10.1093/jhps/hnv034. Epub 2015 May 18.

Is labral hypotrophy correlated with increased acetabular depth?

Felix Toft  1 , Elmar Anliker  2 , Martin Beck  3
Affiliations

Is labral hypotrophy correlated with increased acetabular depth?

Felix Toft et al. J Hip Preserv Surg. 2015 Jul.

Abstract

Labral hypertrophy is a distinct feature in hip dysplasia. Occasionally, very small, hypotrophic labra are observed. However, there is no literature concerning this pathology. We investigated if the size of the labrum correlated with any radiologic parameters reflecting the amount of acetabular coverage. It was hypothezised that there is a negative correlation between labrum size and acetabular coverage. Labra were categorized into three groups depending on the relation between length of the articular sided surface and height of bony attachment. Labra with a height:length ratio of 2 were classified as hypotrophic, with a height:length ratio of 1 as normal and with a ratio of 0.5 as hypertrophic. Labral cross-sectional areas (CSA) were measured on radial magnetic resonance imaging-arthrography slices using the measuring tool of the PACS system of 20 hips with hypotrophic labra (group 1), 20 hips with normal labral appearance (group 2) and 10 hips with hypertrophic labra (group 3). These values were then analyzed against following parameters: neck-shaft-angle (NSA), lateral center-edge angle (LCE), acetabular index (AI), femoral extrusion index (FEI) and acetabular retroversion index (ARI). Analyses of variance were used to determine differences in mean values between the three groups. Mean labral CSA differed significantly between all groups (group 1: 12.1 ± 2.9 mm(2); group 2: 25.2 ± 6.2 mm(2); group 3: 41.1 ± 12.3 mm(2); P < 0.001). NSA, LCE, AI and FEI all showed a significant difference between group 3 and 1 or 2. The ARI showed no difference between groups. Stepwise linear regression analyses showed a significant correlation between LCE angle and labral CSA with a corrected R (2)-value of 0.301. Labral CSA correlates with the LCE. No statistically significant difference between groups 1 and 2 concerning the LCE, AI or FEI could be identified. Nevertheless, group 1 had the highest mean coverage of all groups, hips with hypertrophic labra the lowest.

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Figures

Fig. 1.
Fig. 1.
MR-arthrography showing a hypotrophic labrum (arrow) in the anterosuperior area of the acetabulum.
Fig. 2.
Fig. 2.
Categorization of the labra.
Fig. 3.
Fig. 3.
Clockwise orientation of the analized planes around the acetabulum.
Fig. 4.
Fig. 4.
Boxplot of the size of the labrum of the three groups. 1) hypotrophic, 2) normal, 3) hypertrophic.
Fig. 5.
Fig. 5.
Schematic representation of the size of the labrum for hypotrophic, normal and hypertrophic labra (in mm2).
Fig. 6.
Fig. 6.
Distribution of labral disorders.
See this image and copyright information in PMC

References

    1. Tan V, Seldes RM, Katz MA, et al. Contribution of acetabular labrum to articulating surface area and femoral head coverage in adult hip joints: an anatomic study in cadavera. Am J Orthop 2001; 30: 809–12. - PubMed
    1. Takechi H, Nagashima H, Ito S. Intra-articular pressure of the hip joint outside and inside the limbus. Nippon Seikeigeka Gakkai Zasshi 1982; 56: 529–36. - PubMed
    1. Terayama K, Takei T, Nakada K. Joint space of the human knee and hip joint under a static load. Eng Med 1980; 9: 67–74.
    1. Crawford MJ, Dy CJ, Alexander JW, et al. The 2007 Frank Stinchfield Award. The biomechanics of the hip labrum and the stability of the hip. Clin Orthop Relat Res 2007; 465:16–22. - PubMed
    1. Song Y, Safran M, Ito H, et al. Articular cartilage friction increases in hip joints after partial and total removal of the acetabular labrum . J Biomech 2012; 45: 524–30. - PubMed

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