Total knee arthroplasty in Ranawat II valgus deformity with enlarged femoral valgus cut angle: A new technique to achieve balanced gap

Table 1 Baseline characteristics of 103 cases in conventional total knee arthroplasty group and new theory total knee arthroplasty group

Characteristic	C-TKA group (n = 42 case)	NT-TKA group (n = 61 case)	P value
Knee number (n)	42	61
Age (yr)	62.9 (39-77)	63.5 (38-79)	0.083
Gender, n (%)			0.628
Male	15 (35.71)	19 (31.15)
Female	27 (64.29)	42 (68.85)
BMI (kg/m2)	24.0 ± 2.2	25.1 ± 2.8	0.091
Diagnosis, n (%)			0.770
Primary osteoarthritis	30 (71.43)	44 (72.13)
Rheumatoid arthritis	11 (26.19)	14 (22.58)
Hemophilic arthritis	1 (2.38)	3 (4.92)
FTA (°)	26.8 ± 5.7	26.3 ± 5.2	0.784
Operation time	105.6 ± 17.7	99.2 ± 11.0	0.031
Follow-up (mo)	83.4 ± 10.1	75.6 ± 10.0	0.907

Continuous data are shown as the mean ± SD or median (range), and categorical data are presented as n (%). BMI: Body mass index; FTA: Femorotibial axis; C-TKA: Conventional total knee arthroplasty; NT-TKA: New theory total knee arthroplasty.

Table 2 Comparison of surgery-related results between conventional total knee arthroplasty group and new theory total knee arthroplasty group

Parameter	C-TKA group (n = 42 case)	NT-TKA group (n = 61 case)	P value
HKA (°)
Pre-	17.2 ± 5.9	16.0 ± 4.5	0.076
Post-	0.5 ± 1.0	0.8 ± 1.1	0.225
P value	< 0.001	<0.001	-
ROM (°)
Pre-	73.0 ± 18.7	75.0 ± 20.1	0.369
Post-	93.5 ± 13.6	102.9 ± 11.8	0.781
P value	0.074	< 0.001	-
OKS
Pre-	42.0 ± 4.5	42.8 ± 4.5	0.654
Post-	17.4 ± 3.3	17.8 ± 3.6	0.854
P value	0.038	0.173	-
KSS
Pre-clinical	14.9 ± 12.1	13.9 ± 9.7	0.077
Post-clinical	78.9 ± 6.4	81.3 ± 5.0	0.655
P value	0.010	< 0.001	-
Pre-functional	34.2 ± 19.4	25.7 ± 20.9	0.530
Post-functional	69.9 ± 17.1	60.0 ± 12.1	0.172
P value	0.117	< 0.001	-
KSS clinical stability
Preoperative	9.3 ± 4.4	10.0 ± 4.0	0.378
1 mo (post)	11.2 ± 3.8	13.3 ± 2.9	0.007
Last follow-up	14.3 ± 1.8	14.5 ± 1.5	0.132
Complications	3	0	0.034
Instability	2	0
Nerve injury	1	0
Prosthesis			0.002
Posterior stabilized	36	61
Constrained prosthesis	6	0
Survival rate	42/42	61/61

Continuous data are shown as the mean ± SD. HKA: Hip-knee-ankle; ROM: Range of motion; OKS: Oxford knee score; KSS: Knee society score; C-TKA: Conventional total knee arthroplasty; NT-TKA: New theory total knee arthroplasty.