Reliability of two different measuring techniques with computer tomography for penetration and distribution of cement in the proximal tibia after total knee arthroplasty

Table 2 The median percentages cement at 1, 3 and 5 mm beneath the tibial tray

Distance beneath tibial tray	Quadrant	Observer 1 first measurement % surface cement^a	Observer 1 second measurement % surface cement^a	Observer 2% surface cement^a
		Median [IQR]	Median [IQR]	Median [IQR]
1 mm*	AM	86.37 [80.87–91.56]	86.56 [77.50–91.87]	86.24 [77.03–91.93]
	AL	88.06 [80.87–91.56]	88.08 [80.47–91.42]	88.47 [80.72–91.72]
	PM	85.19 [78.76–91.29]	85.21 [78.09–91.25]	85.25 [78.59–90.84]
	PL	81.95 [73.46–87.73]	82.45 [72.91–88.06]	81.99 [72.50–88.03]
3 mm^#	AM	39.83 [21.96–53.94]	39.19 [22.72–55.58]	38.41 [22.27–53.34]
	AL	53.75 [36.71–66.84]	53.21 [35.76–68.46]	54.34 [37.13–68.31]
	PM	45.76 [24.17–60.07]	46.08 [25.14–58.30]	44.95 [24.96–60.77]
	PL	52.10 [37.64–63.28]	51.86 [36.58–62.26]	52.84 [36.41–64.14]
5 mm^¥	AM	15.07 [11.55–21.98]	15.72 [11.17–19.39]	14.94 [10.80–20.85]
	AL	21.86 [14.79–40.07]	22.27 [15.74–39.52]	21.97 [15.89–40.71]
	PM	17.31 [13.44–29.62]	17.49 [13.03–28.50]	17.59 [13.95–27.59]
	PL	24.80 [16.88–39.25]	25.54 [16.99–38.87]	25.49 [17.05–39.54]

AM Antero-medial, AL Antero-lateral, PM Postero-medial, PL Postero-lateral
^a % Surface cement = percentage of trabecular bone surface that is filled with cement
*Distribution over the quadrants was equal (p = 0.076)
#Distribution over the quadrants was not equal (p = 0.006). Post hoc analysis with a Bonferroni adjustment revealed differences between AM and PL (p = 0.025) and between AM and AL (p = 0.012)
^¥Distribution over the quadrants was not equal (p < 0.001). Post hoc analysis with a Bonferroni adjustment revealed differences between AM and PL (p < 0.001) and between AM and AL (p = 0.005)