Median macroscopic and microscopic scores (± median absolute deviation) for groove and sham joints at week 10.

* Significant difference between groove joints and sham joints (P < 0.05). † Significant differences between dorsal and palmar for the groove joints and sham joints (P < 0.05). Chondrocyte necrosis = chondrocyte-free areas or empty chondrocyte lacunae, or focal cell loss. Chondrocyte clusters = complex chondrone formation. Cartilage matrix softening = cartilage matrix appeared more or less pale and loose, visible in all stains used. Osteoblastic margination = basophilic osteoblastic cells aligned at the border of subchondral bone cavities. Vertical grooves = surgically induced grooves crossing the entire thickness of the non-calcified cartilage extending to the junction with calcified cartilage. Horizontal cracking = cracks at the junction of the non-calcified and calcified cartilage. Median macroscopic and microscopic scores (± median absolute deviation) for groove and sham joints at week 10.