Table 3 Comparison of primary and secondary outcome measures between the HD and non-HD groups

AKSS-knee score at the two year follow-up

95.0 ± 9.8 (72–100)

96.8 ± 5.5 (69–100)

0.4641

Pain

48.1 ± 6.0 (30–50)

49.2 ± 2.8 (30–50)

0.7978

Total range of flexion

23.8 ± 3.6 (12–25)

24.2 ± 1.9 (14–25)

0.3893

Stability

25.0 ± 0.0 (25–25)

25.0 ± 0.0 (25–25)

1.0000

Flexion contracture

1.2 ± 3.3 (0–15)

0.5 ± 0.9 (0–2)

0.7817

Extension lag

0.7 ± 1.8 (0–5)

0.5 ± 2.7 (0–20)

0.1175

Alignment

0.0 ± 0.0(0–0)

0.5 ± 2.3 (0–15)

0.2653

Increase from preoperative score

50.1 ± 19.3 (26–90)

50.2 ± 17.1 (14–91)

0.8633

AKSS-function score at the two year follow-up

73.1 ± 27.2 (0–100)

78.9 ± 18.8 (15–100)

0.6314

Walking

41.4 ± 14.2 (0–50)

45.8 ± 7.9 (20–50)

0.2368

Stairs

33.3 ± 12.8 (0–50)

36.0 ± 10.8 (0–50)

0.6052

Walking aids used

2.1 ± 4.6 (0–20)

3.0 ± 4.9 (0–20)

0.2639

Increase from preoperative score

42.4 ± 29.7 (− 35–90)

45.9 ± 20.6 (− 20–90)

0.8923

AKSS-knee score at the last follow-up

95.4 ± 7.7 (72–100)

97.6 ± 3.4 (83–100)

0.9048

Pain

48.8 ± 3.1 (40–50)

49.3 ± 1.8 (45–50)

0.8595

Total range of flexion

23.5 ± 3.6(12–25)

24.2 ± 2.4 (8–25)

0.8083

Stability

24.5 ± 1.5 (20–25)

25.0 ± 0.0 (25–25)

0.0089

Flexion contracture

1.2 ± 3.3 (0–15)

0.5 ± 1.0 (0–5)

0.6166

Extension lag

0.2 ± 1.1 (0–5)

0.07 ± 0.6 (0–5)

0.3572

Alignment

0.0 ± 0.0(0–0)

0.3 ± 1.5 (0–9)

0.3409

Increase from preoperative score

50.5 ± 18.5 (27–90)

51.0 ± 16.7 (20–98)

0.7979

AKSS-function score at the last follow-up

66.9 ± 33.0 (0–100)

79.2 ± 18.2(15–100)

0.2674

Walking

38.6 ± 16.5 (0–50)

46.1 ± 7.7 (20–50)

0.0330

Stairs

30.0 ± 16.1 (0–50)

36.1 ± 9.9 (0–50)

0.3110

Walking aids used

2.1 ± 4.6 (0–20)

3.0 ± 4.6 (0–20)

0.2640

Increase from preoperative score

36.2 ± 34.3 (− 35–90)

46.1 ± 20.0 (10–85)

0.3269

Postoperative length of stay (days)

25.4 ± 30.8 (9–154)

17.2 ± 3.4 (12–32)

0.4968

Postoperative follow-up period (months)

42.2 ± 25.2 (24–98)

62.7 ± 30.4 (25–150)

0.0047

Operating time (minutes)

83.8 ± 14.5 (64–109)

80.4 ± 20.6 (46–139)

0.2391

Anesthesia time (minutes)

120.3 ± 17.3 (90–155)

117.8 ± 28.1 (67–214)

0.3473

Hemoglobin count on the first postoperative day (g/dL)

10.4 ± 1.5 (7.8–13.2)

10.1 ± 1.2 (7.2–13.2)

0.4453

Hemoglobin count at one week postoperation (g/dL)

9.3 ± 1.2 (7–11.2)

9.7 ± 1.3 (6.8–14.1)

0.3147

Platelet count on the first postoperative day (× 10⁹/L)

18.2 ± 6.1 (8.4–31.3)

17.9 ± 6.8 (5.3–34.0)

0.8269

Platelet count at one week postoperation (× 10⁹/L)

23.2 ± 7.0 (9.1–38.1)

25.2 ± 8.6 (3.0–50.2)

0.2764

Volume of allogenic blood transfusion (mL)

1.1 ± 3.2 (0–14)

0.08 ± 0.5 (0–4)

0.0077