Table 4. Spearman Rank Correlation Between Differences in Flexion and Extension and Age, Body Mass Index (BMI), and Patient-Reported Outcomes

	Flexion Difference			Extension Difference
Variable	n	Rho^{^a}	P Value	n	Rho^{^a}	P Value
Age, years	110	0.082	0.393	110	−0.042	0.662
BMI, kg/m²	110	0.026	0.786	110	0.020	0.835
WOMAC score	98	0.363	0.0002	98	−0.187	0.065
Oxford Knee Score	105	0.339	0.0004	105	−0.235	0.016
WOMAC score^{^b}	98	0.345	0.0006	98	−0.218	0.034
Oxford Knee Score^{^b}	105	0.385	0.0001	105	−0.276	0.007

↵^a Spearman rank correlation coefficient.
↵^b Spearman rank correlation adjusted for sex, age, and BMI.
WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index.