Association of Knee Osteoarthritis and Flexion Contracture With Localized Tibial Articular Cartilage Loss: Data From the Osteoarthritis Initiative

T. Mark Campbell; Odette Laneuville; Guy Trudel

doi:10.3899/jrheum.2023-0743

Article Figures & Data

Tables

Additional Files

View popup

Table 1.

Participant demographics.

	All Participants, n = 578	Participants With Contracture, n = 190	Participants With No Contracture, n = 388
Age, yrs	61.6 (8.9)	62.3 (9.2)	61.2 (8.8)
Female sex, %	59.7	53.2^*	62.9
BMI, kg/m²	30.7 (4.7)	31.1 (4.8)	30.6 (4.7)
KL grade	2.2 (0.7)	2.3 (0.7)	2.2 (0.6)
Maximum knee extension^{^a}, degrees	0.2 (3.9)	−4.4 (2.7)^*	1.8 (2.7)
Knee alignment^{^b}, degrees	−0.4 (3.7)	−0.2 (3.6)	−0.6 (3.8)
WOMAC pain	2.3 (3.1)	2.9 (3.3)^*	2.1 (3.0)
WOMAC function	8.5 (10.6)	10.9 (11.7)^*	7.3 (9.8)
WOMAC stiffness	1.5 (1.5)	1.8 (1.6)^*	1.4 (1.5)
WOMAC total	12.4 (14.5)	15.6 (16.0)^*	10.8 (13.5)

Values are mean (SD) unless otherwise indicated.
↵^a Negative value indicates degrees lacking from full extension.
↵^b Valgus has a negative value.
↵* P < 0.05 for the contracture group vs no contracture group. KL: Kellgren-Lawrence; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index.

View popup

Table 2.

Cartilage thickness and percent of denuded bone for all participants.

Outcome, n = 578	Baseline (95% CI)	Yr 1 (95% CI)	Mean Change Over 1 Yr (95% CI)
Medial tibia
Cartilage thickness, mm
Overall	1.63 (1.60 to 1.65)	1.61 (1.59 to 1.63)	−0.01 (−0.02 to −0.01)^*
Center	2.08 (2.01 to 2.12)	2.05 (2.01 to 2.08)	−0.03 (−0.04 to −0.02)^*
Anterior	1.45 (1.43 to 1.48)	1.45 (1.42 to 1.47)	−0.00 (−0.01 to 0.00)
Posterior	1.40 (1.38 to 1.42)	1.40 (1.38 to 1.42)	−0.00 (−0.01 to 0.00)
Denuded bone, %
Overall	1.41 (1.08 to 1.73)	1.86 (1.47 to 2.24)	0.45 (0.29 to 0.62)^*
Center	0.52 (0.28 to 0.76)	0.92 (0.54 to 1.30)	0.40 (0.19 to 0.61)^*
Anterior	0.87 (0.40 to 1.34)	1.06 (0.60 to 1.53)	0.19 (0.04 to 0.35)^*
Posterior	0.81 (0.47 to 1.15)	0.85 (0.53 to 1.18)	0.04 (−0.05 to 0.13)
Lateral tibia
Cartilage thickness, mm
Overall	1.96 (1.93 to 1.99)	1.95 (1.92 to 1.98)	−0.01 (−0.02 to −0.01)^*
Center	2.97 (2.91 to 3.03)	2.96 (2.90 to 3.02)	−0.01 (−0.03 to 0.00)^*
Anterior	1.64 (1.61 to 1.67)	1.64 (1.62 to 1.67)	0.00 (−0.00 to 0.01)
Posterior	1.64 (1.61 to 1.67)	1.63 (1.60 to 1.66)	−0.01 (−0.02 to −0.01)^*
Denuded bone, %
Overall	1.00 (0.74 to 1.26)	1.07 (0.79 to 1.34)	0.07 (0.01 to 0.12)^*
Center	0.17 (0.05 to 0.29)	0.23 (0.05 to 0.42)	0.07 (−0.01 to 0.14)
Anterior	0.95 (0.44 to 1.46)	0.94 (0.43 to 1.46)	0.01 (−0.11 to 0.09)
Posterior	2.97 (2.24 to 3.70)	3.16 (2.39 to 3.92)	0.19 (0.06 to 0.32)^*

Values in bold are statistically significant.
↵* P < 0.05 for mean change difference from baseline to year 1.

View popup

Table 3.

ANOVA results for contracture interaction with year 1 timepoint.

Outcome, n = 578	Baseline, mean (SD)	Yr 1, mean (SD)	Effect Size, β (95% CI)	P^{^a}
Medial tibia
Cartilage thickness, mm
Overall
Contracture	1.65 (0.29)	1.64 (0.30)	0.003 (−0.01 to 0.01)	0.60
No contracture	1.61 (0.27)	1.60 (0.27)
Center
Contracture	2.12 (0.47)	2.07 (0.49)	−0.01 (−0.03 to 0.02)	0.57
No contracture	2.06 (0.43)	2.03 (0.43)
Anterior
Contracture	1.48 (0.29)	1.48 (0.29)	0.004 (−0.01 to 0.02)	0.59
No contracture	1.44 (0.29)	1.43 (0.29)
Posterior
Contracture	1.43 (0.28)^*	1.44 (0.28)	0.01 (0.002 to 0.03)	0.02
No contracture	1.38 (0.26)	1.38 (0.26)
Denuded bone, %
Overall
Contracture	1.55 (3.87)	2.23 (5.05)	0.19 (−0.17 to 0.54)	0.30
No contracture	1.33 (4.06)	1.68 (4.56)
Center
Contracture	0.55 (2.88)	1.31 (6.32)	0.44 (0.02 to 0.86)	0.04
No contracture	0.51 (3.03)	0.74 (3.59)
Anterior
Contracture	0.62 (3.64)	0.73 (3.30)	−0.22 (−0.55 to 0.11)	0.19
No contracture	0.99 (6.60)	1.22 (6.56)
Posterior
Contracture	0.75 (3.30)	0.88 (3.46)	0.09 (−0.11 to 0.28)	0.38
No contracture	0.84 (4.46)	0.84 (4.19)
Lateral tibia
Cartilage thickness, mm
Overall
Contracture	1.97 (0.36)	1.96 (0.37)	0.002 (−0.01 to 0.01)	0.76
No contracture	1.95 (0.37)	1.94 (0.37)
Center
Contracture	3.01 (0.69)	3.00 (0.70)	0.01 (−0.02 to 0.03)	0.70
No contracture	2.95 (0.71)	2.94 (0.72)
Anterior
Contracture	1.64 (0.35)	1.65 (0.36)	0.01 (−0.01 to 0.02)	0.68
No contracture	1.64 (0.30)	1.64 (0.30)
Posterior
Contracture	1.66 (0.36)	1.64 (0.36)	−0.002 (−0.02 to 0.01)	0.82
No Contracture	1.63 (0.36)	1.62 (0.36)
Denuded bone, %
Overall
Contracture	1.44 (3.92)^*	1.51 (4.00)^*	−0.04 (−0.16 to 0.08)	0.52
No contracture	0.78 (2.67)	0.85 (3.07)
Center
Contracture	0.27 (1.73)	0.32 (1.98)	−0.08 (−0.21 to 0.04)	0.17
No contracture	0.12 (1.40)	0.19 (2.44)
Anterior
Contracture	2.11 (10.03)	2.21 (10.32)	0.20 (−0.03 to 0.42)	0.09
No contracture	0.39 (2.82)	0.32 (2.39)
Posterior
Contracture	3.61 (9.69)	3.71 (9.85)	−0.17 (−0.45 to 0.11)	0.23
No contracture	2.65 (8.51)	2.88 (9.08)
Summary of ANOVA Findings for Regional Effect of Contracture
	Medial		Lateral
Anterior	–		↑ % denuded bone (trend)
Center	↑ % denuded bone		–
Posterior	Cartilage preservation		–

Values in bold are statistically significant.
↵^a For contracture interaction with year 1 outcome after controlling for baseline outcome and adjusting for the continuous variables age, BMI, WOMAC total score, knee alignment, ordinal variable baseline KL, and the nominal variables sex and race.
↵* P < 0.05 for the contracture group vs no contracture group. KL: Kellgren-Lawrence; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index.