TABLE V.

Patient-Reported Outcome Scores at Baseline and 2 Years Postoperatively, Stratified by Preoperative Compartment-Specific Osteoarthritis Research Society International (OARSI) Score^*

Patient-Reported Outcome	Low Medial, Low Lateral	Low Medial, High Lateral	High Medial, Low Lateral	High Medial, High Lateral	P Value
WOMAC pain
Baseline	43.5 (17.1)	38.4 (17.5)	36.5 (16.4)	41.1 (17.9)	0.57
2 yr	10.1 (20.2)	7.4 (11.6)	5.7 (10.6)	7.8 (12.2)	0.47
Change from baseline to 2 yr	−33.4 (15.6)	−31.0 (15.4)	−30.7 (19.2)	−33.4 (15.3)	0.69
KOOS ADL at baseline	55.0 (16.3)	61.8 (16.3)	62.6 (15.7)	58.6 (17.4)	0.73
KOOS ADL at 2 years	86.7 (19.5)	89.5 (16.2)	92.6 (10.6)	90.7 (12.0)	0.26
Change in KOOS ADL from baseline to 2 years	31.8 (16.1)	27.7 (16.3)	29.9 (19.1)	32.0 (17.3)	0.35

^*Patient-reported outcome scores are reported separately for 4 preoperative compartment-specific OARSI score combinations: low medial, low lateral (milder osteoarthritis of the medial and lateral compartments); low medial, high lateral (milder osteoarthritis of the medial compartment, more severe arthritis of the lateral compartment); high medial, low lateral (more severe osteoarthritis of the medial compartment, milder osteoarthritis of the lateral compartment); and high medial, high lateral (more severe arthritis of the medial and lateral compartments). Continuous variables are given as the mean, with the standard deviation in parentheses. P values represent comparison across all compartment-specific OARSI score combinations, as assessed by the Kruskal-Wallis test. WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain is scaled 0 to 100, with 100 being the worst pain. KOOS ADL (Knee injury and Osteoarthritis Outcome Score activities of daily living) is scaled 0 to 100, with 100 being the best function.