Comparison of general data
No patients in either group quit or were lost to follow-up. No statistical difference in sex ratio, age, BMI, and operation time between the two groups was found (P > 0.05, Table 1).
Table 1. Comparison of general data and operation time between the two groups
Group
|
Age (years)
|
Male/female
|
BMI (kg/㎡)
|
Operation time (min)
|
Group PL
|
63.57±12.41
|
13/17
|
24.12±4.02
|
91.63±28.20
|
Group S
|
62.90±13.45
|
13/17
|
23.85±3.29
|
101.83±34.58
|
t/χ2
|
0.200
|
0.000
|
0.281
|
1.252
|
P
|
0.67
|
1.00
|
0.78
|
0.22
|
Abbreviations: BMI, body mass index
Primary results
Comparison of NRS scores of resting pain before and after block between the two groups
The generalized estimation equation showed no significant difference in NRS scores of resting pain among different groups and interaction between groups and time (P > 0.05), but there was a significant difference at different time points (P < 0.05). The comparison between the two groups at the same time point showed no significant difference in the NRS scores of resting pain before and after administering nerve block (P > 0.05). In Group PL, the NRS score of resting pain at 48 h after blockage was significantly lower than that at 1 h, 6 h, 12 h, and 24 h after blockage. In Group S, the NRS scores of resting pain at 24 h and 48 h after blockage were significantly lower than that at 1 h, 6 h, and 12 h after block (P < 0.05, Table 2).
Table 2. Comparison of Numerical Rating Scale (NRS) scores of resting pain before and after block between the two groups [n=30, P50 (P25, P75)]
Group
|
Before block
|
1 h
|
6 h
|
12 h
|
24 h
|
48 h
|
Group PL
|
3 (2,4)
|
0 (0, 2)a
|
0 (0, 2)a
|
0 (0, 2)a
|
0 (0, 1)a
|
0 (0, 0)a-e
|
Group S
|
4 (2,5)
|
1.5 (0, 2)a
|
1 (0, 2)a
|
0.5 (0, 2)a
|
0 (0, 1)a-d
|
0 (0, 0)a-d
|
Waldχ2
|
0.045
|
3.671
|
1.205
|
0.265
|
0.358
|
0.205
|
P
|
0.83
|
0.06
|
0.27
|
0.61
|
0.55
|
0.65
|
Waldχ2intergroup = 0.978, P=0.323; Waldχ2 time = 219.631, P=0.000; Waldχ2 intergroup * time= 6.033, P=0.303.
a compared with pre-block, b compared with 1 h, c compared with 6 h, d compared with 12 h, e compared with 24 h, all P < 0.05.
Comparison of the NRS of motor pain at each time point after administering block between the two groups
No significant difference was found in the NRS scores of motor pain among different groups and interaction between groups and time (P > 0.05), but there was a significant difference in different time points (P < 0.05). Comparing the two groups at the same time point showed no significant difference in the NRS scores of motor pain at each time point before and after blockage (P > 0.05). In Group PL, the NRS scores during exercise pain at 48 h after block were significantly lower than those at 1 h, 6 h, 12 h, and 24 h after blockage. Meanwhile, in Group S, NRS scores at 24 h and 48 h after blockage were significantly lower than those at 1 h, 6 h, and 12 h after blockage (P < 0.05, Table 3).
Table 3. Comparison of NRS scores of motor pain before and after block between the two groups [n=30, P50 (P25, P75)]
Group
|
1 h
|
6 h
|
12 h
|
24 h
|
48 h
|
Group PL
|
3 (2,4)
|
3 (2.75,4)
|
3 (2,4)
|
3 (2, 3.25)b,c
|
2 (2,2.25)a-d
|
Group S
|
3 (2,4)
|
3 (2,4)
|
3 (2,4)
|
3 (2, 3)a-c
|
2.5 (2, 3)a-c
|
Waldχ2
|
0.606
|
0.418
|
0.318
|
0.392
|
1.245
|
P
|
0.44
|
0.52
|
0.57
|
0.53
|
0.27
|
Waldχ2intergroup = 0.121, P=0.728; Waldχ2 time = 80.547, P=0.000; Waldχ2 intergroup * time= 5.248, P=0.263.
a compared with 1 h; b compared with 6 h, c compared with 12 h, d compared with 24 h, all P < 0.05.
Abbreviations: NRS, Numerical Rating Scale
Comparison of postoperative analgesic drugs and analgesic satisfaction between the two groups
No remedial analgesia was used in either group. No significant difference in the number of additional analgesic pumps and the dosage of sufentanil required within 24 h and 24–48 h was found between the two groups (P > 0.05, Table 4). The postoperative pain satisfaction of the two groups was 9 (8, 9) in Group PL and 9 (8, 9) in Group S, with no significant difference (Z=-0.848, P=0.397). The satisfaction of 48-hour analgesia was 9 (9, 10) in Group PL and 9 (9, 9) in Group S, with no significant difference (Z=-0.591, P=0.554).
Table 4. Number of analgesic pump and dosage of sufentanil within 24 h and 48 h after block in the two groups [n=30, P50(P25, P75)]
Group
|
Additional times within 24 h
|
Dosage of sufentanil (ug) within 24 h
|
Additional times within 24–48 h
|
Dosage of sufentanil (ug) within 48 h
|
Group PL
|
0 (0,4)
|
72 (72,75)
|
0 (0,4)
|
144 (144,147)
|
Group S
|
0 (0,2)
|
72 (72,73.5)
|
0 (0,2)
|
144 (144,145.5)
|
Z
|
-0.688
|
-0.635
|
-0.549
|
-0.627
|
P
|
0.50
|
0.53
|
0.58
|
0.53
|
Comparison of muscle strength at each time point after administering nerve blocks in the two groups
Compared with Group PL, Group S had a higher rate of quadriceps weakness at 1 h and 6 h after blockage, and the difference was statistically significant (P < 0.05, Table 5). The rate of adductor muscle weakness in Group S was higher than that in Group PL at 1 h and 6 h after blockage (P < 0.05, Table 6).
Table 5. Weakness of quadriceps femoris at each time point after block in the two groups [n=30, n(%)]
Group
|
1 h
|
6 h
|
12 h
|
24 h
|
48 h
|
Group PL
|
5 (16.7)
|
4 (13.3)
|
2 (6.7)
|
0 (0.0)
|
0 (0.0)
|
Group S
|
24 (80.0)
|
21 (70.0)
|
7 (23.3)
|
2 (6.7)
|
0 (0.0)
|
χ2
|
24.093
|
19.817
|
2.092
|
0.517
|
-
|
P
|
<0.001
|
<0.001
|
0.15
|
0.47
|
-
|
Table 6. Abductor muscle weakness at each time point after block in both groups [n=30, n(%)]
Group
|
1 h
|
6 h
|
12 h
|
24 h
|
48 h
|
Group PL
|
4 (13.3)
|
4 (13.3)
|
2 (6.7)
|
1 (3.3)
|
0 (0.0)
|
Group S
|
21 (70.0)
|
16 (53.3)
|
5 (16.7)
|
2 (6.7)
|
0 (0.0)
|
χ2
|
19.817
|
10.800
|
0.647
|
0.000
|
-
|
P
|
<0.001
|
0.001
|
0.42
|
1.00
|
-
|
Secondary results
Comparison of skin sensory block between the two groups 30 min after blockage
Thirty minutes after administering nerve block, the anterior thigh sensation of patients in Group PL decreased in 11 cases (36.7%), which was significantly lower than those in Group S (100%; χ2 = 27.8, P < 0.01). There were nine cases (30.0%) with hypoesthesia in the medial thigh in Group PL, which was significantly lower than that in Group S (73.3%; χ2 = 11.279, P < 0.01). There were 30 cases (100%) in Group PL and 29 cases (96.7%) in Group S, with no significant difference (χ2 = 0, P=1. 0).
Comparison of postoperative hospitalization time and adverse reactions
The postoperative hospital stay was 7.00 (4.75, 8.25) days in Group PL and 6.00 (4.00, 7.25) days in Group S, with no significant difference (Z=-1. 029, P=0. 303). Postoperative nausea and vomiting occurred in four cases (13.3%) in Group PL and six cases (20.0%) in Group S; while postoperative dizziness occurred in four cases (13.3%) in Group PL and four cases (13.3%) in Group S. No puncture site infection and hematoma was present in the patients of both groups, and had no significant difference for adverse events (P > 0.05).