Inverted Rearfoot posture in subjects with coexisting patellofemoral osteoarthritis in medial knee osteoarthritis: an exploratory study

Table 2 Comparison of calcaneus inverted angle and calcaneus alignment in knees with and without PFOA (n = 68)

Variables	Coexisting Any PFOA (n = 38 knees)	Isolated TFOA (n = 30 knees)	p-value^†	Difference in mean (95% CI)^††	p-value
Calcaneus inverted angle, degrees§	1.046 ± 5.053	−2.245 ± 5.648	0.014	3.109 (0.037, 6.181)	0.047
Calcaneus alignment, no (%)§§			0.218
Everted calcaneus	5 (13.2)	8 (26.7)
Normal calcaneus	27 (71.1)	20 (66.7)
Inverted calcaneus	6 (15.8)	2 (6.7)

PFOA: patellofemoral osteoarthritis; TFOA: tibiofemoral osteoarthritis; 95% CI: 95% confidence interval
Except where otherwise indicated, values are mean ± SD
^†Based on Student t-test (calcaneus inverted angle) and the Fisher’s exact tests (calcaneus type) between two groups
^††Adjusted for age, (continuous), sex (0: male, 1: female), body mass index (continuous), tibiofemoral joint Kellgren/Lawrence grade (continuous), corrected anatomical axis angle (continuous), presence of varus thrust (0: absence, 1: presence), and knee flexion range of motion (continuous)
^§A positive value indicates inversion direction of the calcaneus.
^§§Inverted calcaneus: calcaneus angle ≤ − 5 degree; normal calcaneus: −5 degree < and ≤ 5 degree; everted calcaneus: calcaneus angle > 5 degree.
Bold type represents a statistically significant result

ISSN: 1757-1146