Tibial component rotation alters soft tissue balance in a cruciate retaining total knee arthroplasty

Figures & data

Table 1. Contact pressure results obtained for each tibial rotation with mean pressures (Psi) and range in brackets.

		Tibial component rotation
Degrees of knee flexion	Compartment	Akagi’s line	Insall’s axis	p Value (t-test)
10°	Medial	18.3 (6–36)	33.7 (8–63)	0.049
	Lateral	15.9 (5–37)	40 (11–124)	0.018
	Difference	5.2 (0–13)	25.5 (2–61)	<0.001
45°	Medial	18.3 (6–44)	32.2 (5–94)	0.115
	Lateral	12.7 (6–35)	27.8 (7–81)	0.038
	Difference	10.8 (1–30)	27.6 (5–76)	0.023
90°	Medial	20.3 (8–82)	30.7 (6–134)	0.392
	Lateral	13.6 (5–36)	34.6 (10–85)	0.008
	Difference	13.5 (1–76)	34.9 (10–117)	0.060

Bold values were the significant values with p<0.05

Table 2. Number of TKA exceeding maximal recommended contact pressure at each tibial rotation (n = 12).

Number of knees exceeding maximal recommended contact pressure of 30Psi (n = 12)
Knee flexion	Akagi’s line	Insall’s axis	p Value (chi-square)
10°	1	8	0.003
45°	4	7	0.219
90°	3	9	0.014

Bold values were the significant values with p<0.05

Figure 1. (a–c) Box and whisker plots of intercompartmental pressure differences(psi) observed when tibial component rotated to each tibial rotational landmark at 10°(a), 45°(b) and 90°(c) of knee flexion.

Table 3. Number of TKA balanced at each tibial rotation (n = 12 patients).

	Tibial component rotation
Knee flexion	Akagi’s line	Insall’s axis	p Value (chi-square)
10°	12	5	0.002
45°	8	2	0.013
90°	9	3	0.014

Bold values were the significant values with p<0.05