Abstract
ObjectiveTo explore the difference in pelvic tilt and hip joint parameters with developmental dysplasia of the hip (DDH) comparing the anteroposterior (AP) pelvic radiographs taken in supine and standing positions.MethodsA prospective study of DDH patients undergoing Bernese periacetabular osteotomy (PAO) was conducted. AP pelvic radiographs were taken in supine and standing positions before surgery The pelvic tilt and hip joint parameters from the two radiographs were compared. Contrast parameters included the distance between the pubic symphysis to sacrococcygeal distance (PSSC), lateral center‐edge angle (LCEA), Tönnis angle (TA), and angle of sharp (SA).ResultsA total of 110 young DDH patients were enrolled, including 32 men and 78 women, aged 18–49 years. The male PSSC was 45.63 ± 13.69 mm in supine position and 36.91 ± 12.33 mm in standing position (P < 0.05). The female PSSC was 56.76 ± 13.54 mm in supine position and 48.62 ± 15.44 mm in standing position (P < 0.05). In this study, LCEA <20° in AP pelvic radiographs in the supine position was found in 52 men and 135 women. For male patients, in supine position and standing position, LCEA were 5.51° ± 11.88° and 4.45° ± 12.22°, respectively (P < 0.05); TA were 20.20° ± 9.63° and 21.30° ± 9.97°, respectively (P < 0.05), and SA comparison showed no significant differences. For female patients, in supine position and standing position, LCEA were 3.07° ± 12.07° and 1.69° ± 12.11°, respectively (P < 0.05), TA were 22.62° ± 9.31° and 23.82° ± 9.45°, respectively (P < 0.05), and SA were 48.01° ± 4.68° and 48.49° ± 4.74°, respectively (P < 0.05).ConclusionCompared with the supine position, the young DDH patients have pelvic tilt backward and a decrease in hip coverage in the standing position.
Highlights
Anteroposterior (AP) pelvic radiographs are usually taken in supine position
Characteristics of Hip Cover Changes from Supine to Standing Position in Patients with Developmental Dysplasia of the Hip In this study, lateral center-edge angle (LCEA)
In supine position and standing position, LCEA were 3.07 Æ 12.07 and 1.69 Æ 12.11, respectively (P < 0.05), Tönnis angle (TA) were 22.62 Æ 9.31 and 23.82 Æ 9.45, respectively (P < 0.05), and SA were 48.01 Æ 4.68 and 48.49 Æ 4.74, respectively (P < 0.05). These results showed that LCEA was decreased, and TA and SA were increased in developmental dysplasia of the hip (DDH) patients from supine position to standing position (Table 3). (Figs 2 and 3)
Summary
Anteroposterior (AP) pelvic radiographs are usually taken in supine position. Surgeons have tended to take AP pelvic radiographs in standing position as it obtains acetabular coverage and joint appositions in functional position[1]. Except that the pelvis needs to bear the weight of the upper body in standing position, the question remains of whether there are any other differences between the two positions. Konishi et al.[2] measured the lateral pelvic radiographs and reported the presence of an approximate 5. Difference in the pelvic tilt between supine position and standing position. Lateral pelvic radiographs can be used to assess the pelvic tilt, there are particular requirements in regard to shooting position. Several shots were required to Received 1 September 2019; accepted 15 October 2019
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