From: Preoperative Ahlbäck radiographic classification grade significantly influences clinical outcomes of double level osteotomy for osteoarthritic knees with severe varus deformity
Ahlbäck grade
Preoperative KOOS
Postoperative 2-year KOOS
1
185.2 ± 46.6
420.2 ± 42.9
2
182.0 ± 70.4
393.9 ± 67.3
3
192.5 ± 79.1
350.0 ± 79.9*
4
171.7 ± 38.2
317.9 ± 78.3*†