Author Year Country Study type Animal Modeling method Types of stem cells Source of stem cells Injection dose Control Observation time Imaging-based evaluation indicators Friedmann et al. [1 ] 2021 Germany RCT Merino sheep, female Nucleotomy ADSCs+collagen hydrogel Sheep Not provided 12 months Disc height Schmitt et al. [8 ] 2021 Germany RCT Merino sheep, female Nucleotomy ADSCs+chitosan carboxymethyl cellulose hydrogel scaffold Sheep Not provided 12 months Disc height Choi et al. (1) [9 ] 2020 Korea RCT Sprague-Dawley rats, female Needle puncture WJ-MSCs+HAMC Human PBS 6 weeks MRI index Choi et al. (2) [9 ] WJ-MSCs Xiao et al. (1) [10 ] 2020 China RCT Mice Needle puncture Sod2-ADSCs Human Not provided 8 weeks DHI MRI index T2 signal intensity Xiao et al. (2) [10 ] Cat-ADSCs Xiao et al. (3) [10 ] Null-ADSCs Xiao et al. (4) [10 ] ADSCs Yan et al. (1) [15 ] 2019 China RCT New Zealand white rabbits Nucleus pulposus aspiration BMSCs+SAB Rabbits PBS 8 weeks T2 signal intensity Yan et al. (2) [15 ] BMSCs Ma et al. (1) [16 ] 2018 China RCT New Zealand white rabbits Needle puncture ADSCs+PRP Human PBS 4 weeks MRI signal score Ma et al. (2) [16 ] ADSCs Zhou et al. (1) [17 ] 2018 China RCT New Zealand white rabbits Needle puncture ADSCs+NPCS Human Not provided 16 weeks DHI MRI index Zhou et al. (2) [17 ] ADSCs Ishiguro et al. [18 ] 2018 Japan RCT Sprague-Dawley rats, male Nucleotomy ADSCs+TEC Rats NP reimplantation 6 months DHI Endplate degeneration score Hussain et al. [19 ] 2018 United States RCT Finn sheep Nucleotomy BMSCs+HDC Sheep 2.5 × 105 HDC 6 weeks DHI Pfirrmann grade NP mid-sectional volume NP T2 relaxation time Zhu et al. (1) [20 ] 2018 China RCT Sprague-Dawley rats, male Needle puncture ADSCs+PEAD+GDF5 Human Not provided PEAD+ GDF5 24 weeks DHI MRI index T2 signal intensity Zhu et al. (2) [20 ] ADSCs+GDF5 Lykov et al. (1) [21 ] 2018 Russia RCT Wistar rats, male Needle puncture BMSCs+EPO Rats Not provided 3 weeks Disc height Lykov et al. (2) [21 ] BMSCs Li et al. [22 ] 2016 China RCT New Zealand white rabbits Nucleotomy BMSCs+DSP Rabbits DSP 12 weeks DHI Wang et al. [23 ] 2015 China RCT New Zealand white rabbits, male Needle puncture BMSCs+PRP Sheep PRP 8 weeks MRI signal score Chen et al. [24 ] 2015 China RCT New Zealand white rabbits, male Nucleus pulposus aspiration NPSCs Human NPCs 2 months DHI T2 signal intensity Wang et al. (1) [25 ] 2014 China RCT New Zealand white rabbits Nucleus pulposus aspiration BMSCs+AFCs Rabbits Not provided Saline 2 weeks Disc height ratio Pfirrmann grade Wang et al. (2) [25 ] BMSCs Freeman et al. (1) [26 ] 2014 Australia RCT Merino wether sheep Nucleotomy BMSCs into AF Sheep PBS 12 months DHI Disc height Pfirrmann grade Freeman et al. (2) [26 ] BMSCs into NP Cai et al. [27 ] 2014 China RCT New Zealand white rabbits Needle puncture BMSCs Rabbits PBS 10 weeks T2 signal intensity T2 relaxation time DHI Yi et al. (1) [28 ] 2013 China RCT New Zealand white rabbits Needle puncture TIMP1-BMSCs Rabbits PBS 12 weeks DHI Yi et al. (2) [28 ] BMSCs Feng et al. [29 ] 2010 China RCT New Zealand white rabbits Nucleus pulposus aspiration BMSCs Rabbits NPCs 16 weeks DHI T2 signal intensity Jeong et al. [30 ] 2010 Korea RCT Sprague-Dawley rats, female Needle puncture ADSCs Human Saline 6 weeks Disc height T2 signal intensity Yang et al. [31 ] 2009 China RCT New Zealand white rabbits Nucleus pulposus aspiration BMSCs+PFG-TGF-b1 Rabbits PFG-TGF-b1 12 weeks DHI Sakai et al. [32 ] 2005 Japan RCT New Zealand white rabbits Nucleus pulposus aspiration BMSCs Rabbits Atelocollagen 24 weeks T2 signal intensity DHI