BACKGROUND: The effect of fixed @entity85 on a functional pelvis from standing to sitting is not fully understood. We aimed to assess the change in preoperative sagittal pelvic tilt angle (SPTA) from standing to sitting in @entity1 undergoing total hip arthroplasty, comparing flexible and fixed @entity85 . METHODS: Between July 2011 and October 2011, 68 consecutive unilateral total hip arthroplasties were implanted in 68 @entity1 with a mean age of 71    6 years. Fixed @entity85 was defined as <10   of the change in SPTA from standing to sitting. Preoperative radiographic evaluation included standing (weight-bearing) anteroposterior and lateral pelvic and lumbosacral radiographs and a sitting lateral pelvic radiograph. RESULTS: The mean standing and sitting SPTA was 3.7   of anterior tilt and 17.7   of posterior tilt, respectively (change of 21.4    12.5  ). Seventy-five percent had flexible pelvises, all of which had a posterior tilt from standing to sitting. One @entity1 in the fixed pelvis (1.4%) had a loss of posterior tilt from standing to sitting. The mean change of SPTA from standing to sitting in the fixed and flexible pelvis groups was 5.9    3.5   to 26.7    9.6   of posterior tilt, which was statistically significant (P < .05). CONCLUSION: There was a significant change in sagittal pelvic tilt from standing to sitting, especially in @entity1 with a flexible spine, in which the functional anteversion increases with sitting. The @entity1 with a fixed pelvis had significantly less SPTA in standing (less anteversion) with less posterior sagittal tilt in sitting, which should be incorporated in cup positioning.

Effect of XXXX on Pelvic Orientation from Standing to Sitting Position.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity85 :: ('MESH:D009140', 'Disease') :: ['spinal deformities', 'spinal deformity']
@entity85 :: (MESH:D009140,Disease) :: ['Spinal Deformity']
