Table 4 Comparison of the radiographic results in octogenarians who underwent primary or revision total knee arthroplasty

Mechanical axis (degrees)

Preoperative

Varus 12.3 ± 7.3 (varus 27.3 – valgus 15.1)

Varus 8.8 ± 9.7 (varus 22.8 – valgus 9.8)

0.045

Postoperative

Varus 1.0 ± 3.3 (varus 5.3 –valgus 4.7)

Varus 2.8 ± 4.3 (varus 7.4 – valgus 5.2)

0.003

Position of components (degrees)

α angle

95.6 ± 1.9 (92.6–99.8)

95.7 ± 2.9 (92.1–99.9)

0.938

β angle

90.8 ± 2.0 (86.3–93.7)

90.5 ± 1.7 (86.6–93.9)

0.316

γ angle

4.2 ± 3.3 (− 2.5–7.9)

3.2 ± 4.1 (− 2.3–7.2)

0.096

δ angle

86.2 ± 3.1 (84.5–89.7)

86.1 ± 3.7 (81.5–90.2)

0.923