Table 1. WORMS cartilage lesion scoring system.

adopted from Peterfy et al. and utilized to score the frequency and severity of cartilage lesions in the five knee cartilage compartments (lateral femur, medial femur lateral tibia, medial tibia and patella). Each cartilage lesion was scored on the following eight-point scale:

0	normal cartilage thickness and signal intensity
1	normal cartilage thickness or swelling with abnormal signal on fluid-sensitive sequences
2	single partial-thickness focal cartilage lesion < 1 cm in greatest width
2.5	single full-thickness focal cartilage lesion < 1 cm in greatest width
3	multiple areas of partial-thickness (grade 2) cartilage lesions intermixed with areas of normal cartilage thickness or a grade 2 cartilage lesion wider than 1 cm but < 75% of the region
4	diffuse (≥75% of the region) partial-thickness cartilage loss
5	multiple areas of full-thickness loss (grade 2.5) or a grade 2.5 lesion wider than 1 cm but < 75% of the region
6	diffuse (≥75% of the region) full-thickness cartilage loss