Medium-term efficacy of arthroscopic debridement vs conservative treatment for knee osteoarthritis of Kellgren-Lawrence grades I-III

Table 1 Baseline data in the two groups

Variable	Group A	Group B	t-value	χ2 value	P value
Number of patients	98	80
Age (yr), mean ± SD	59.27 ± 14.48	58.75 ± 14.66	-0.235	-	0.815
Female/male	74/24	60/20	-	0.006	0.937
BMI, mean ± SD	24.60 ± 2.74	24.92 ± 2.68	0.776	-	0.439
Side of KOA (left/right)	44/54	36/44	-	0.000	0.989
Kellgren-Lawrence grade
1	26	23	-	0.109	0.742
2	22	19	-	0.042	0.838
3	50	38	-	0.218	0.640
HSS score before treatment, mean ± SD	78.65 ± 11.20	79.10 ± 11.41	0.263	-	0.793

Statistical difference between the two groups was tested by t test or χ² analysis. Statistical significance was set at P < 0.05. SD: Standard deviation; BMI: Body mass index; KOA: Knee osteoarthritis; HSS: American hospital for special surgery knee score; Group A: Arthroscopic debridement group; Group B: Conservative treatment group.

Table 2 American hospital for special surgery knee scores of the two groups before and after treatment

		HSS score, mean ± SD
	n	Before treatment	1st mo after treatment	3rd mo after treatment	6th mo after treatment	12th mo after treatment	24th mo after treatment
Group A	98	78.65 ± 11.20	87.76 ± 9.10	91.08 ± 5.67	91.88 ± 6.48	92.18 ± 5.90	92.08 ± 5.85
Group B	80	79.10 ± 11.41	85.05 ± 10.21	87.19 ± 9.32	87.46 ± 9.91	87.79 ± 9.59	87.31 ± 10.15
t value		0.263	-1.867	-	-	-	-
t′ value		-	-	-3.277	-3.433	-3.584	-3.729
P value		0.793	0.064	0.001	0.001	0.000	0.000

Statistical difference between the two groups was tested by t test or t′ test. The comparisons between American hospital for special surgery knee (HSS) scores before treatment and HSS scores at 1, 3, 6, 12, and 24 mo after treatment were performed by analysis of variance. Further pairwise comparisons of multiple data were conducted by the S-N-K method (q test) when variance was homogeneous, or Games-Howell method when variances was not homogeneous. Statistical significance was set at P < 0.05. n: Number of patients of the two groups; SD: Standard deviation; HSS: American hospital for special surgery knee score; Group A: Arthroscopic debridement group; Group B: Conservative treatment group.

Table 3 Visual analogue scale scores at walking time of the two groups before and after treatment

		VAS score, mean ± SD
	n	Before treatment	1st mo after treatment	3rd mo after treatment	6th mo after treatment	12th mo after treatment	24th mo after treatment
Group A	98	4.06 ± 1.55	1.73 ± 1.63	1.31 ± 1.44	1.04 ± 1.41	0.94 ± 1.29	0.94 ± 1.26
Group B	80	4.08 ± 1.47	2.45 ± 1.58	1.63 ± 1.39	1.35 ± 1.41	1.15 ± 1.30	1.10 ± 1.27
t value		-0.060	-2.946	-1.493	-1.459	-1.081	-0.847
t′ value		-	-	-	-	-	-
P value		0.952	0.004	0.137	0.146	0.281	0.398

Statistical difference between the two groups was tested by t test or t′ test. The comparisons between visual analogue scale (VAS) scores at walking time before treatment and VAS scores at walking time at 1, 3, 6, 12, and 24 mo after treatment were performed by analysis of variance. Further pairwise comparisons of multiple data were conducted by the S-N-K method (q test) when variance was homogeneous, or Games-Howell method when variances was not homogeneous. Statistical significance was set at P < 0.05. n: Number of patients of the two groups; SD: Standard deviation; VAS: Visual analogue scale; Group A: Arthroscopic debridement group; Group B: Conservative treatment group.

Table 4 Visual analogue scale scores at rest time of the two groups before and after treatment

		VAS score, mean ± SD
	n	Before treatment	1st mo after treatment	3rd mo after treatment	6th mo after treatment	12th mo after treatment	24th mo after treatment
Group A	98	1.22 ± 2.03	0.49 ± 1.19	0.02 ± 0.14	0.02 ± 0.14	0.02 ± 0.14	0.02 ± 0.14
Group B	80	1.21 ± 2.01	0.68 ± 1.39	0.21 ± 0.59	0.21 ± 0.59	0.21 ± 0.59	0.21 ± 0.59
t value		0.039	-	-	-	-	-
t′ value		-	-0.942	-2.851	-2.851	-2.851	-2.851
P value		0.969	0.348	0.005	0.005	0.005	0.005

Statistical difference between the two groups was tested by t test or t′ test. The comparisons between visual analogue scale (VAS) scores at rest time before treatment and VAS score at rest time at 1, 3, 6, 12, and 24 mo after treatment were performed by analysis of variance. Further pairwise comparisons of multiple data were conducted by the S-N-K method (q test) when variance was homogeneous, or Games-Howell method when variances was not homogeneous. Statistical significance was set at P < 0.05. n: Number of patients of the two groups; SD: Standard deviation; VAS: Visual analogue scale; Group A: Arthroscopic debridement group; Group B: Conservative treatment group.