Table 3 Intra-observer measurement agreements

Group A (n = 58)

 Hip-knee-ankle angle

0.996

0.993–0.997

< 0.001

0.990

0.983–0.994

< 0.001

 Weight-bearing line ratio

0.995

0.991–0.997

< 0.001

0.965

0.942–0.980

< 0.001

 Medial proximal tibial angle

0.935

0.890–0.962

< 0.001

0.954

0.923–0.973

< 0.001

 Lateral distal femoral angle

0.940

0.899–0.964

< 0.001

0.988

0.981–0.993

< 0.001

 Joint-line convergence angle

0.937

0.894–0.963

< 0.001

0.980

0.967–0.988

< 0.001

 K-L grade (FLWAP radiographs)

0.844

0.933

 K-L grade (PA radiographs)

0.845

0.843

Group B (n = 85)

 Hip-knee-ankle angle

0.987

0.980–0.991

< 0.001

0.979

0.968–0.986

< 0.001

 Weight-bearing line ratio

0.995

0.992–0.997

< 0.001

0.992

0.987–0.995

< 0.001

 Medial proximal tibial angle

0.879

0.814–0.921

< 0.001

0.904

0.853–0.938

< 0.001

 Lateral distal femoral angle

0.961

0.940–0.975

< 0.001

0.988

0.980–0.992

< 0.001

 Joint-line convergence angle

0.927

0.887–0.952

< 0.001

0.925

0.884–0.951

< 0.001

 K-L grade (FLWAP radiographs)

0.885

0.856

 K-L grade (PA radiographs)

0.834

0.854

Group C (n = 32)

 Hip-knee-ankle angle

0.996

0.992–0.998

< 0.001

0.999

0.998-1.000

< 0.001

 Weight-bearing line ratio

0.997

0.993–0.998

< 0.001

0.958

0.915–0.980

< 0.001

 Medial proximal tibial angle

0.867

0.727–0.935

< 0.001

0.885

0.765–0.943

< 0.001

 Lateral distal femoral angle

0.927

0.852–0.964

< 0.001

0.985

0.969–0.993

< 0.001

 Joint-line convergence angle

0.901

0.797–0.951

< 0.001

0.893

0.781–0.948

< 0.001

 K-L grade (FLWAP radiographs)

0.751

0.841

 K-L grade (PA radiographs)

0.823

0.832