Table 2 Risk factors for THA requirement after RAO assessed by univariate and multivariate regression analyses

  Age at the time of surgery

1.248

1.059–1.471

0.008

  Body mass index

0.986

0.711–1.369

0.934

  Smoking history

0.036

0.000–67.106

0.386

  Presence of cysts

7.329

0.900–59.685

0.063

  Deformity of the femoral head

0.515

0.063–4.208

0.536

  Center edge angle (°)

0.958

0.909–1.011

0.119

  Sharp angle (°)

1.056

0.892–1.250

0.527

  Acetabular head index (%)

0.964

0.909–1.022

0.220

  Acetabular roof obliquity (°)

1.023

0.923–1.134

0.662

  Obturator foramen-head distance (mm)

1.200

0.972–1.481

0.091

  Joint space width (mm)

0.655

0.449–0.957

0.029

  Radiographic stage

2.691

1.205–6.013

0.016

  Center edge angle (°)

0.996

0.944–1.052

0.896

  Sharp angle (°)

1.058

0.969–1.154

0.206

  Acetabular head index (%)

0.992

0.931–1.057

0.803

  Acetabular roof obliquity (°)

1.023

0.966–1.083

0.435

  Obturator foramen-head distance (mm)

0.982

0.838–1.152

0.828

  Joint space width (mm)

0.674

0.428–1.060

0.088

  Radiographic stage

1.693

0.664–4.317

0.271

  Joint congruity

1.981

0.898–4.372

0.091

  Thickness of the transferred acetabulum

0.991

0.848–1.159

0.911

 Age at the time of surgery

1.293

1.041–1.606

0.020

 Preoperative Joint space width

1.327

0.533–3.301

0.543

 Radiographic stage

4.155

0.413–41.812

0.227