Outcomes of mobile bearing unicompartmental knee arthroplasty in medial osteoarthritis knee with and without preoperative genu recurvatum

Table 1 Demographic data

Variable	Group I (patients with preoperative genu recurvatum),n = 32 knees	Group II (patients without preoperative genu recurvatum),n = 144 knees	P-value
Age	65.10 ± 8.02 (57-76)	65.67 ± 7.40 (44-88)	0.71
Sex, male/female	1/31	14/130	0.31
Site, right/left	16/17	70/74	0.91
BMI	26.76 ± 3.69 (20.81-33.21)	26.26 ± 3.05 (20-42.22)	0.47
Knee score	34.10 ± 2.47 (27-44)	34.35 ± 2.62 (30-40)	0.61
Pain score	11.52 ± 4.42 (0-20)	11.75 ± 4.94 (0-20)	0.23
Functional score	54.69 ± 9.75 (30-65)	52.03 ± 10.13 (35-65)	0.18
ROM (°)	122.58 ± 4.17 (110-125)	119.37 ± 10.92 (90-130)	0.10
Tibiofemoral angle (°)	Varus 5.45 ± 3.86 (0-20)	Varus 5.68 ± 3.99 (0-15)	0.77

BMI: Body mass index; ROM: Range of motion.

Table 2 Pain score, knee score and functional score at 2-yr follow-up

Variable	Group I (patients with preoperative genu recurvatum),n = 32 knees	Group II (patients without preoperative genu recurvatum),n = 144 knees	P-value
Knee score, points	97.97 ± 2.49 (94-100)	96.91 ± 4.44 (81-100)	0.19
Pain score, points	48.94 ± 2.36 (45-50)	48.71 ± 2.63 (40-50)	0.64
Functional score, points	82.12 ± 4.85 (80-100)	82.55 ± 5.10 (65-100)	0.66

Table 3 Incidence of postoperative genu recurvatum and postoperative hyperextension angle

Variable	Group I (patients with preoperative genu recurvatum),n = 32 knees	Group II (patients without preoperative genu recurvatum),n = 144 knees	P-value
Incidence of postoperative genu recurvatum (%)	3.13 (1/32)	0.69 (1/144)	0.34
Hyperextension angle (°)	2.40 ± 2.19 (1-7))	1.57 ± 3.51 (1-6)	0.65

Table 4 Postoperative range of motion, component alignment, postoperative tibiofemoral angle and operative time

Variable	Group I (patients with preoperative genu recurvatum),n = 32 knees	Group II (patients without preoperative genu recurvatum),n = 144 knees	P-value
Postoperative ROM (°)	126.21 ± 5.30 (115-135)	123.30 ± 9.88 (90-145)	0.14
Postoperative tibiofemoral angle (°)	5.82 ± 1.55 (valgus 3-valgus 8)	5.66 ± 1.77 (valgus 2-valgus 10)	0.65
Femoral component alignment (°)	6.06 ± 1.43 (valgus 2-valgus 8)	5.99 ± 1.56 (valgus 2-valgus 10)	0.82
Tibia component alignment (°)	Varus 0.97 ± 0.92 (varus 3-valgus 1)	Varus 0.77 ± 1.19 (varus 3-valgus 2)	0.37
Posterior slope of tibial component (°)	6.73 ± 1.92 (4-10)	6.31 ± 2.04 (2-10)	0.28
Operative time in min	88.94 ± 10.59 (75-120)	93.01 ± 13.64 (65-130)	0.11

ROM: Range of motion.