Table 1.
Characteristics of studies included in the meta-analysis.
| Author(s)/year/country/design | Patients (I: C); female proportion (I: C) | Age (I: C) | BMI (I: C) | Intervention vs. control | Intervention frequency, duration, and time | Intervention intensity | Main outcome measures |
|---|---|---|---|---|---|---|---|
| Avramidis et al. /2003/UK/2-arm RCT | 15(I):15(C); 10/15(I):12/15(C) | 68.20 ± 10.59(I): 71.20 ± 7.83(C) | Not mentioned | NMES+ conventional PT vs. Conventional PT | NMES (40 Hz, 300 μs) of the vastus medialis for 2 h on each occasion, twice daily, from the second day postoperative to the 6 weeks postoperative | Maximum tolerable intensity | 3MWT, PCI, HSS at 6, 12 weeks postoperatively |
| Petterson et al./2009/US/2-arm RCT | 100(I): 100(C); 47/100(I): 45/100(C) | 65.3 ± 8.3(I): 65.2 ± 8.5(C) | 29.67 ± 4.85(I): 29.99 ± 3.90(C) | NMES+ exercise vs. Exercise | NMES 2 or 3 times per week for 6 weeks with a minimum requirement of 12 therapy visits | Maximum tolerable intensity | SF-36 (PCS, MCS), KOS-ADLS, pain-KOS, TUG, SCT, 6MWT, active flexion ROM, active extension ROM and CAR (NMVIC, newtons/BMI) at 3, 12 months postoperatively |
| Valdés et al./2010/Spain/2-arm RCT | 39(I): 44(C); 25/39(I): 25/44(C) | 72 ± 6(I): 70 ± 7(C) | 32.3 ± 4.7(I): 32.4 ± 6.3(C) | NMES+ standard rehabilitation vs. Standard rehabilitation | NMES (65 Hz, 300 μs, 15–30 mA) of feedback to the quadriceps for 15 min once a day from the day after surgery | Not mentioned | BA, TUG, WOMAC pain, WOMAC stiffness, WOMAC function at 1, 3 months; LOS |
| Avramidis et al. /2011/Greece/2-arm RCT | 35(I): 35(C); 28/35(I): 29/35(C) | 70.54 ± 4.68(I): 70.66 ± 3.73(C) | 27.38 ± 2.65(I): 27.14 ± 3.31(C) | NMES+ conventional physiotherapy vs. Conventional physiotherapy | NMES (40 Hz, 300 μs) of the vastus medialis muscle twice daily for 2 h from the second postoperative day | Maximum tolerable intensity | AKSS, OKS, SF-36, 3MWT, PCI at 6, 12, and 52 weeks postoperatively |
| Stevens-Lapsley et al./2012/US/2-arm RCT | 35(I): 31(C); 20/35(I): 16/31(C) | 66.2 ± 9.1(I): 64.8 ± 7.7(C) | 27.1 ± 4.9(I): 31.2 ± 4.2(C) | NMES+ standard rehabilitation vs. Standard rehabilitation | NMES (600 μs) twice daily from 2 days after surgery | Maximum tolerable intensity | Quadriceps and hamstring muscle strength, TUG, SCT, 6MWT, NPRS, active flexion ROM, active extension ROM, SF-36 (PCS, MCS), WOMAC, GRS at 3.5, 6.5, 13, 26, 52 weeks postoperatively |
| Levine et al./2013/US/2-arm RCT | 35(I): 35(C); 25/35(I): 21/35(C) | 68.1(I): 65.1(C) | 30.6(I): 31.9(C) | NMES+ ROM exercise vs. therapist-managed PT | NMES used from the second day postoperatively | Not mentioned | KSS pain, KSS function, WOMAC, passive flexion ROM, passive extension ROM, TUG at 6 weeks and 6 months postoperatively |
| Demet et al./2015/Turkey/2-arm RCT | 30(I): 30(C); 28/30(I): 29/30(C) | 66.2 ± 7.2(I): 64.6 ± 6.6(C) | 29.1 ± 3.9(I): 30.1 ± 4.6(C) | NMES+ exercise vs. Exercise | NMES (30–100 Hz, 400 μs, 28–90 mA) of the vastus medialis muscle for 30 min, 5 days a week from the first day postoperatively. | Maximum tolerable intensity | flexion ROM, extension ROM, TUG, WOMAC, SF-36, VAS at 1, 3 months postoperatively |
| Yoshida et al./2017/Japan/3-arm RCT | 22 (sNMES): 22 (mNMES): 22 (Control); 18/22 (sNMES): 18/22 (mNMES): 20/22 (Control) | 71.6 ± 7.0 (sNMES):75.9 ± 4.7 (mNMES):72.5 ± 6.2 (Control) | 25.4 ± 2.2 (sNMES): 24.6 ± 2.9 (mNMES): 25.8 ± 3.3 (Control) | sNMES+ standard rehabilitation vs. mNMES+ standard rehabilitation vs. Standard rehabilitation | sNMES (100 Hz, 1 ms, 10–15 mA, 45 min/day) and mNMES (100 Hz, 1 ms, 15–38 mA, 45 min/day) 5 days/week for 2 weeks from the second weeks postoperatively | Sensory-level intensity (sNMES) and maximum tolerable intensity (mNMES) | MVIC, LSMM, TUG, 2MWT, VAS (0–100 mm), passive flexion ROM and passive extension ROM at 2 weeks postoperatively |
| Klika et al./2020/US/2-arm RCT | 24(I): 22(C); 18/24(I): 17/22(C) | 65 ± 5.8(I): 65 ± 7.6(C) | Not mentioned | NMES+ standard PT vs. Standard PT | NMES (15–85 V, 50 pps, 5 ms) for 200 min/week, 12 weeks from the day of surgery | Maximum tolerable intensity | Quadriceps strength, ROM, resting pain, TUG, SCT, KOOS and VR-12 at 3, 6, and 12 weeks postoperatively |
I, Intervention; C, Control; BMI, body mass index; RCT, randomized controlled trial; NMES, neuromuscular electrical stimulation; PT, physical therapy; 3MWT, 3-minute walking test; PCI, hysiological Cost Index; HSS, Hospital for Special Surgery knee score; ROM, range of motion; TUG, timed up and go test; 6MWT, 6-minute walk test; MVIC, normalized maximal volitional isometric contraction; CAR, the central activation ratio; BMI, body mass index; SCT, stair climbing test; SF-36, Short Form 36; PCS, physical component score; MCS, mental component score; KOS ADLS, Knee Outcome Survey Activities of Daily Living scale; BA, balance articular; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index; LOS, length of stay; AKSS, American Knee Society clinical score; OKS, Oxford knee score; NPRS, Numeric Pain Rating Scale; GRS, global rating scale; KSS, knee Society score; VAS, visual analogue scale; sNMES, sensory-level neuromuscular electrical stimulation; mNMES, motor- level neuromuscular electrical stimulation; LSMM; leg skeletal muscle mass; 2MWT, 2-minute walk test; KOOS, Knee injury and Osteoarthritis Outcome Score; VR-12, veterans rand-12.