High tibial osteotomy with human umbilical cord blood-derived mesenchymal stem cells implantation for knee cartilage regeneration

Table 2 Clinical outcomes according to the International Cartilage Repair Society grading system

	ICRS grade I (n = 73)	ICRS grade II (n = 37)	ICRS grade III (n = 15)	P value1	Post hoc5
IKDC
Preoperative	28.4 ± 7.4	30.1 ± 7.2	29.2 ± 8.1	0.610
1 yr	59.3 ± 8.7	52.4 ± 10.7	54.8 ± 7.1	0.005	I > II = III,I = III
2 yr	64.3 ± 9.2	58.6 ± 11.1	55.0 ± 8.0	< 0.001	I > II = III
3 yr	68.1 ± 10.8	61.0 ± 11.3	59.3 ± 5.8	< 0.001	I > II = III
P value2	< 0.001	< 0.001	0.001
P value3	< 0.001	< 0.001	0.842
P value4	0.001	0.063	0.047
WOMAC
Preoperative	45.1 ± 11	41.9 ± 9.2	44.3 ± 12.2	0.275
1 yr	11.0 ± 6.9	16.8 ± 8.5	17.6 ± 5.1	< 0.001	I > II = III
2 yr	8.4 ± 6.0	13.4 ± 8.2	17.3 ± 7.4	< 0.001	I > II = III
3 yr	6.5 ± 6.0	10.5 ± 5.6	12.6 ± 8.3	< 0.001	I > II = III
P value2	< 0.001	< 0.001	0.001
P value3	< 0.001	0.001	0.607
P value4	0.003	0.002	0.018
VAS
Preoperative	7.6 ± 1.4	7.5 ± 1.1	7.7 ± 0.8	0.817
1 yr	2.1 ± 1.7	3.0 ± 1.6	3.3 ± 1.2	0.002	I > II = III
2 yr	1.5 ± 1.4	2.7 ± 1.8	3.1 ± 1.2	< 0.001	I > II = III
3 yr	1.1 ± 1.5	2.0 ± 1.4	2.6 ± 0.9	< 0.001	I > II = III
P value2	< 0.001	< 0.001	0.001
P value3	< 0.001	0.229	0.658
P value4	0.004	0.019	0.103

Boldface indicates statistical significance (P < 0.05).

¹Kruskal-Wallis test.

²Wilcoxon signed-rank test: Preoperative vs 1 year postoperatively.

³Wilcoxon signed-rank test: 1 year postoperatively vs 2 years postoperatively.

⁴Wilcoxon signed-rank test: 2 years postoperatively vs 3 years postoperatively.

⁵Bonferroni adjustment using the Mann-Whitney U test. ICRS: International Cartilage Repair Society; IKDC: International Knee Documentation Committee; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index; VAS: Visual analog scales.