Table 1. Characteristics of the included comparisons in RCTs and the results of conventional meta-analysis.
| First author/year/country | K-L grade |
No. of cases (MSC/CON) | Mean age (SD) |
n (%) females | Entity of cells |
No. of cells |
Source | Delivery method | Placebo | FU periods (months) | Pain scale | Function scale |
Structural assessment |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Vega, 2015, Spain | 2–4 | 30 (15/15) | MSC: 56.6 (9.6); CON: 57.3 (9.4) | MSC: 60%; CON: 67% | BM-MSCs | 4×107 | Allogenic | 1-stage injection | HA | 12 | VAS | WOMAC-global | NR |
| Gupta, 2016, India | 2–3 | 60 (40/20) | MSC: 57.7 (8.6); CON: 54.9 (8.3) | MSC: 75%; CON: 100% | BM-MSCs | (2.5–15)×107 | Allogenic | 1-stage injection | HA | 12 | VAS | WOMAC-PF | WORMS |
| Lamo-Espinosa, 2016, 2018, Spain | 2–4 | 30 (20/10) | MSC: 61.6 (8.3); CON: 58.7 (5.2) | MSC: 40%; CON: 30% | BM-MSCs | (1, 10)×107 | Autologous | 2-stage injection | HA | 12 | VAS | WOMAC-PF | WORMS |
| Emadedin, 2018, Iran | 2–4 | 43 (19/24) | MSC: 51.7 (9.2); CON: 54.7 (5.3) | MSC: 37.5%; CON: 36.8% | BM-MSCs | 4×107 | Autologous | 1-stage injection | NS | 6 | VAS | WOMAC-PF | NR |
| Kuah, 2018, Australia | 1–3 | 20 (16/4) | MSC: 52.9 (6.5); CON: 55.0 (10.4) | MSC: 31%; CON: 75% | AD-MSCs | (3.9, 6.7)×106 | Allogenic | 1-stage injection | NR | 12 | VAS | WOMAC-PF | cartilage defect in MRI |
| Matas, 2019, Chile | 1–3 | 26 (18/8) | MSC: 56.4 (5.5); CON: 54.8 (4.5) | MSC: 61%; CON: 63% | UC-MSCs | (2, 4)×107 | Allogenic | 1, 2-stage injection | HA | 12 | VAS | WOMAC-PF | WORMS |
| Lee, 2019, South Korea | 2–4 | 24 (12/12) | MSC: 62.2 (6.5); CON: 63.2 (4.2) | MSC: 75%; CON: 75% | AD-MSCs | 1×108 | Autologous | 1-stage injection | NS | 6 | VAS | WOMAC-PF | cartilage defect in MRI |
CON, control group; FU, follow-up; No. of cells, number of injected cells; No. pts, number of participants included; NR, not reported; RCTs, randomized controlled trials; SD, standard deviation; HA, hyaluronic acid; NS, normal saline; UC-MSC, umbilical cord-derived mesenchymal stromal cells; AD-MSCs, adipose tissue-derived mesenchymal stromal cells; BM-MSCs, bone marrow-derived mesenchymal stromal