Coronal plane stability of cruciate-retaining total knee arthroplasty in valgus gonarthrosis patients: A mid-term evaluation using stress radiographs

Table 1 Patient demographic data (n = 28 knees)

Parameters	Values
Age (years)	72.6 (8.0)1
Sex, n (%)
Female	24 (96.4)
Side, n (%)
Right	18 (64.2)
BMI	27.1 (3.3)1
ASA classification, n (%)
1	3 (10.7)
2	23 (82.1)
3	2 (7.1)
Krackow classification, n (%)
1	21 (75)
2	7 (5)
Preop mechanical axis (degrees)	11.31 (36-27.3)
Preop tibial slope (degrees)	9.0 (4.4)1
Prosthesis, n (%)
PFC sigma	15 (53.6)
NRG scorpio	11 (39.3)
Attune	1 (3.5)
Legion	1 (3.5)
Follow-up time (years)	3.41 (Range 10-7.4)

¹Mean (standard deviation).

BMI: Body mass index; ASA: American Society of Anesthesiologists.

Table 2 Interobserver reliability of radiographic measurement data

Parameters	Cronbach’s alpha
Preop mechanical axis (degrees)	0.981
Postop mechanical axis (degrees)	0.820
Preop tibial slope (degrees)	0.802
Postop tibial slope (degrees)	0.929
Varus gap opening (mm)	0.964
Varus gap opening (degrees)	0.972
Valgus gap opening (mm)	0.821
Valgus gap opening (degrees)	0.921
Alpha angle (degrees)	0.819
Beta angle (degrees)	0.757

Table 3 Postoperative radiographic outcomes

Parameters	Values
Postop mechanical axis (degrees) (negative value represents varus angle)	0.4 (-0.4 to 2.3)2
Postop tibial slope (degrees)	3.7 (2.4-7.1)2
Alpha angle (degrees)	93.7 (2.1)1
Beta angle (degrees)	89.6 (1.0)1
Varus gap opening (mm)	1.6 (0.6-3.0)2
Varus gap opening (degrees)	2.5 (1.3-4.8)2
Valgus gap opening (mm)	2.0 (1.6-2.3)2
Valgus gap opening (degrees)	2.3 (2.0-3.6)2

¹Mean (standard deviation).

²Median (interquartile range).

Table 4 Postoperative clinical outcomes

Parameters	Values
WOMAC	20.5 (17-48)2
KSS Knee	91.5 (85-94.5)2
KSS Function	71.6 (22.7)1
Range of motion (degree)
Extension	1.9 (3.9)1
Flexion	113.9 (12.6)1
TUGT (second)	13 (11.5-18.5)2

¹Mean (standard deviation).

²Median (interquartile range).

WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index questionnaire; KSS: Knee Society score; TUGT: Time Up and Go test.