Arthroscopy combined with unicondylar knee arthroplasty for treatment of isolated unicompartmental knee arthritis: A long-term comparison

Table 1 Comparison of the patients' data between groups A and B

Characteristic	Group A	Group B	t/Z/X2	P
Number of UKA	60	58	0.416	0.519
Bilateral surgeries	6	7
Age (yr)	61.2 ± 8.4	63.0 ± 8.1	1.169	0.245
Gender (Male/Female)	12/48	19/39	2.478	0.115
Side (Left/Right)	21/39	27/31	1.631	0.212
Height (cm)	160 (156-163)	160 (156-167)	1.190	0.234
Weight (kg)	69.0 (63.0-75.8)	70.0 (64.5-78.3)	0.989	0.323
Body mass index (kg/m²)	27.1 ± 3.2	27.2 ± 3.5	0.167	0.868
Etiology (OA/Post-traumatic arthritis)	57/3	55/3	0.142	0.766
Follow-up period (yr)	7.08 (6.42-7.83)	7.08 (6.42-7.83)	0.100	0.921

UKA: Unicondylar knee arthroplasty; OA: Osteoarthritis.

Table 2 Inpatient information of the two groups

	Group A	Group B	Z/X2	P
Hospitalization time (d)	12.0 (11.0-14.75)	10.5 (9.0-13.3)	2.246	0.025
Hemorrhage during operation (mL)	100 (50-100)	50 (50-100)	1.484	0.138
Total volume of blood transfusion (mL)	0 (0-350)	350 (0-565)	3.325	0.001
Percentage of patients receiving blood transfusion (%)	40	67.2	8.795	0.003
Percentage of patients developing complications after operation (%)	1.7	1.7	0.475	0.491

Table 3 Modes of failure in both groups and follow-up

Group	Number of of knees	Mean time to revision (yr)	Follow-up years
Group A
Progression of arthritis	2	6.92	7.42
Aseptic loosening	1	6.33	7.33
Group B
Progression of arthritis	3	6.33	6.86
Bearing dislocation	1	1	9.58

Table 4 Outcome scores and radiological information of the two groups at pre-operation and last follow-up

Group	Pre-operation	Last follow-up	mean difference (95%CI)	P
Group A
HSS score	59.6 ± 10.9	82.7 ± 9.3	23.2 (19.3-27.0)	0.000
Knee society score	47.3 ± 6.3	76.2 ± 13.1	28.9 (25.1-32.7)	0.000
Knee function score	57.5 ± 6.3	75.1 ± 19.6	17.5 (12.1-23.0)	0.000
FTA	179.9 ± 3.5	175.2 ± 2.5	4.7 (3.5-5.8)	0.000
HKA	175.1 ± 2.8	176.7 ± 3.1	1.6 (0.4-2.7)	0.008
ROM	121.5 ± 8.2	129.1 ± 11.5	7.6 (4.1-11.2)	0.000
Group B
HSS score	59.3 ± 15.6	84.3 ± 10.1	23.7 (18.9-28.5)	0.000
Knee society score	49.1 ± 9.2	75.1 ± 13.2	24.7 (19.9-29.5)	0.000
Knee function score	59.3 ± 9.0	77.4 ± 13.8	17.2 (12.8-21.6)	0.000
FTA	181.5 ± 5.0	175.0 ± 3.7	6.2 (4.5-7.8)	0.000
HKA	173.9 ± 3.7	176.5 ± 3.2	2.5 (1.0-4.0)	0.001
ROM	116.1 ± 17.3	131.1 ± 14.1	14.2 (8.7-19.7)	0.000

HSS: Hospital for special surgery; FTA: Femoral-tibial angle; HKA: Hip-knee-ankle angle; ROM: Range of motion.