Table 3 Comparison of preoperative and two years postoperative period of functional outcomes between the cemented polyethylene (PE) and convertible metal-backed (MB) groups

Follow-up, months

26.8 ± 3.0

26.7 ± 2.5

Pain, VAS

Preoperative

7.0 ± 1.9

6.9 ± 1.3

2-year follow-up

1.5 ± 2.2

0.5 ± 1.1

p-value

< 0.001^*

< 0.001^*

Forward flexion, °

Preoperative

110.9 ± 32.7

121.2 ± 33.7

2-year follow-up

144.8 ± 26.3

156.8 ± 21.9

p-value

< 0.001^*

< 0.001^*

External rotation, °

Preoperative

29.6 ± 14.1

31.5 ± 11.7

2-year follow-up

66.5 ± 17.1

69.2 ± 12.5

p-value

< 0.001^*

< 0.001^*

Internal rotation at back, VL

Preoperative

14.1 ± 2.9

13.3 ± 3.1

2-year follow-up

9.6 ± 2.4

9.4 ± 2.1

p-value

< 0.001^*

< 0.001^*

ASES score

Preoperative

37.7 ± 18.6

42.5 ± 8.7

2-year follow-up

87.2 ± 15.0

91.8 ± 12.3

p-value

< 0.001^*

< 0.001^*

SST

Preoperative

2.8 ± 2.3

3.1 ± 1.6

2-year follow-up

8.1 ± 3.9

9.9 ± 2.7

p-value

< 0.001^*

< 0.001^*

DASH score

Preoperative

55.7 ± 22.9

46.2 ± 19.1

2-year follow-up

11.0 ± 15.2

8.7 ± 9.0

p-value

< 0.001^*

< 0.001^*