Acetabular labral tear is associated with high pelvic incidence with or without femoroacetabular impingement morphology

Abstract

Purpose The aim of this study was to investigate the association between pelvic sagittal parameters and acetabular labral tears. Methods Three-hundred and sixty-five patients (449 hips) who underwent magnetic resonance imaging (MRI) or magnetic resonance arthrogram (MRA) for hip pain were enrolled in this study. Pelvic sagittal parameters, including the pelvic incidence, pelvic tilt, and sacral slope, were measured with a standing lumbosacral lateral radiograph. All subjects were divided into two groups according to the presence or absence of radiologic acetabular labral tears and compared. Furthermore, the two groups were divided into subgroups according to whether femoroacetabular impingement (FAI) morphology was present or not and compared. Results Pelvic incidence was greater in the labral tear group than in the non-labral tear group (52.3° ± 8.2° versus 47.1° ± 6.8°, p < 0.001). After accounting for potentially confounding variables, we found that higher age (odds ratio 1.04, 95% confidence interval [CI] 1.02 to 1.06, p = 0.001), FAI (odds ratio 15.11, 95% CI 7.43 to 30.75, p < 0.001), and high pelvic incidence (odds ratio 1.13, 95% CI 1.09 to 1.17, p < 0.001) were independently associated with acetabular labral tear. When only the patients without FAI (308 hips) were divided into groups with and without acetabular labral tear, we found that higher age (odds ratio 1.03, 95% CI 1.01 to 1.06, p = 0.008) and high pelvic incidence (odds ratio 1.15, 95% CI 1.11 to 1.19, p < 0.001) were independently associated with acetabular labral tear. Conclusion Acetabular labral tear is associated with high pelvic incidence with or without FAI morphology. Level of evidence III.

The Effect of Pelvic Incidence on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement and Acetabular Labral Tears

“…2,23,52,54 Additionally, spine users may compensate by posteriorly tilting their pelvis; however, this maladaptive postural response effectively causes functional undercoverage of the femoral head anteriorly, thereby creating a more verticalized articular loading surface of the acetabulum. 13,23,24,27,48 Even in the absence of FAI, previous literature has suggested that the deleterious loading of the anterior acetabulum may be the impetus for acetabular labral tears, nontraumatic femoral head collapse, and accelerated rates of osteoarthritis. 14,23,24,54 Thus, impingement may not be the primary driver of symptoms for all patients with FAI, but rather the resulting compensatory adjustments seen in the setting of high PI could underlie the relatively worse functional outcomes observed in the present study.…”

“…42,48 As a result, patients with low PI often attempt to maintain sagittal alignment and a normal degree of lumbar lordosis by anteriorly tilting the pelvis (ie, decreasing PT). 23,52,54 This anterior tilt of the pelvis may impose overcoverage of the anterosuperior acetabulum and reduced flexion at the hip joint, a hallmark of symptomatic FAI. Although the etiopathogenesis of FAI remains highly debated, studies have gone further to suggest that cam deformities may be directly associated with decreased PI.…”

“…21 However, independent of FAI, studies have found sagittal alignment to be closely correlated with health-related quality of life measures, and recent investigations have further revealed that abnormal spinopelvic anatomy may be innately linked to pathologies of the spine and hip. 2,14,16,19,23,24,47…”

“…42 Over time, degenerative stiffening of the lumbar spine may demand further extremes of hip/pelvis mobility to maintain native alignment, with hip-specific literature citing associations with the development of acetabular labral tears, femoral head osteonecrosis, premature osteoarthritis, and even inferior outcomes after THA. 2,14,19,23,24,47 Overall, the misappropriation of load absorption and force transduction imposed by spinopelvic malalignment can contribute to accelerated arthrosis of both adjacent facets and neighboring large joints. 27,45 Thus, while osteoplasties may mitigate degenerative loading patterns caused by FAI, native variations in lumbosacral alignment may continue to pose deleterious implications in the context of hip preservation surgery.…”

The significance of the pelvic incidence measurement as a possible predictor of TKA outcome

“…The pelvic incidence is calculated as the sum of the pelvic tilt and sacral slope and, thus, is a position‐independent anatomical parameter of sagittal plane spinopelvic balance, with the normal range of 35 − 85° [18]. Several studies have previously shown that the pelvic incidence is associated with the development of spondylolisthesis [29], hip osteoarthritis [8], progression in osteonecrosis of the femoral head [15], and acetabular labral tear [16]. Consistent with the current study (Fig.…”