Relationship between hip joint proximity area and sagittal balance parameters: an upright computed tomography study

Abstract

Purpose A close relationship between sagittal spinal alignment and hip osteoarthritis (OA) has been documented. This study aimed to examine the relationship between hip joint proximity area and sagittal balance parameters in healthy subjects. Methods This prospective study enrolled 47 healthy volunteers who underwent 320-detector row upright computed tomography. Acquired data were reconstructed in a virtual three-dimensional space. The proximity area was determined by < 1 mm of the Hausdorff distance between the acetabulum and the femoral head. Volunteers were divided into the anterior and posterior proximity groups depending on the position of the closest area. Sagittal balance parameters [sagittal vertical axis (SVA), T1 spinopelvic inclination (T1-SPi), T1-pelvic angle, pelvic tilt, sacral slope, pelvic incidence, lumbar lordosis, thoracic kyphosis), offset distance between the centre of the acoustic meati (CAM) and C7 plumb line (CAM-C7-offset), and offset distance between the CAM and hip axis (HA) (CAM-HA-offset)] were compared between the two groups using independent sample t test. Results The anterior proximity group (n = 24) had higher SVA (p = 0.016) and T1-Spi (p = 0.015) than the posterior proximity group (n = 23). CAM-HA-offset was higher in the posterior than in the anterior proximity group (p < 0.000). There was no difference in other parameters (p > 0.05). Conclusion The anterior proximity group had a positive anterior spinal balance; the posterior proximity group may have a more posterior gravity line than the hip joint centre. The anterior spinal balance may contribute to the anterior loading of the hip joint, with known relation with the initiation and onset of hip OA.

Correlation between Acetabular Anteversion with a False-Profile View and Spinopelvic Parameters in Adult Spinal Deformity after Long-Segment Corrective Spinal Surgery

“…However, there are no reports directly evaluating the changes in the anterior coverage of the acetabulum in the standing position. Recently, reports have evaluated these changes using upright CT, which may be useful for providing detailed bone morphometry in the upright position 12 ; however, this imaging modality lacks versatility and can subject the patient to radiation exposure. In this regard, the false-profile view can be easily evaluated with a simple X-ray in the evaluation of standing acetabular coverage.…”