Review Article

Minimally Manipulated Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis: A Systematic Review of Clinical Evidence

Table 2

Clinical studies regarding the use of stromal vascular fraction (SVF) in the treatment of knee osteoarthritis.

PublicationStudy designDiseaseTherapeutic protocolOutcomePatient characteristicF-upMain findings

Jones et al. [28]RCT (NCT03242707)OAComparative study: ultrasound-guided, intra-articular injection of autologous adipose tissue vs. HAWOMAC, PROMIS questionnaire, synovial fluid analysis, sway velocity assessment54 (27 vs. 27)
Age: N/A
Sex: M-F: N/A
K-L: N/A
6 monthsOngoing.
Roato et al. [29]ProspectiveOAFollowing diagnostic arthroscopy, 35 ml of concentrated adipose tissue was injected intra-articularlyWOMAC, VAS, MRI, immunohistochemistry of 2 knees20
Age: 59.6
Sex: M-F: 9-11
K-L: I-III
18 monthsWhilst both WOMAC and VAS scores improved significantly, WOMAC scores showed progressively better outcomes. MRI Outerbridge grade did not show significant changes. Immunohistochemistry displayed new tissue growth.
Hong et al. [33]Double-blind RCT (HA in contralateral knee)Bilateral OAComparative study: arthroscopic debridement followed by intra-articular SVF injection vs. HA injection in the contralateral kneeVAS, WOMAC, ROM, whole-organ MRI score, MRI observation of cartilage repair tissue16 (32 knees): (16 vs. 16)
Age: 18-70 years
Sex: M-F:
K-L: II-III
12 monthsVAS and WOMAC scores and knee ROM improved significantly for both groups, but these improvements were not long lasting in the control group. MRI analysis showed significantly increased cartilage repair in the SVF group compared to the control.
Hudetz et al. [26]ProspectiveOAMicrofragmented adipose tissue injectionVAS, radiographs, dGEMRIC MRI, IgG isolation from plasma and synovial fluid17 (32 knees)
Age: 40-85
Sex: M-F: 12-5
K-L: III-IV
12 monthsSignificant decrease in VAS scores. No change in IgG glycome composition. dGEMRIC MRI analysis displayed increase in proteoglycan content within the ECM.
Bansal et al. [30]Prospective (phase I)
NCT03089762
OASVF+PRP injectionWOMAC, 6-minute walking distance, MRI10 (13 knees)
Age: ≥50
Sex: N/A
K-L: I-II
24 monthsSignificant improvement of WOMAC scores and 6-minute walking distance. MRI showed increase in cartilage thickness in all but 2 patients. All patients are satisfied with therapy.
Yokota et al. [27]ProspectiveOAIntra-articular injection of SVFVAS, WOMAC, Japanese Knee Osteoarthritis Measure (JKOM)13 (26 knees)
Age: 74.5
Sex: M-F: 2-11
K-L: III-IV
6 monthsAll VAS, WOMAC, and JKOM scores improved significantly at the 6-month (last) follow-up.
Nguyen et al. [37]Comparative prospectiveOAComparative study: arthroscopic microfracture (AM) and SVF+PRP injection vs. AM aloneWOMAC, VAS, and Lysholm scores, MRI, knee joint function30 (15 vs. 15)
Age: 58.60 vs. 58.20
Sex: M-F: 3-12vs. 3-12
K-L: II-III
18 monthsWOMAC, Lysholm, and VAS scores improved for both groups up to 12 months, but at 18 months, the SVF group was significantly better than the control group. At 12 months, the SVF group displayed significantly less bone marrow edema than the control group.
Koh et al. [36]ProspectiveOAFollowing arthroscopic lavage is intra-articular injection of SVF+PRP to the most severe cartilaginous defectsLysholm, VAS, and KOOS scores, radiographs, 2nd-lookarthroscopy30
Age: ≥60
Sex: M-F: 5-25
K-L: II-III
24 monthsLysholm, VAS, and KOOS scores all improved significantly. Scores increased at the second year compared to the first year of follow-up. Second-look arthroscopy determined the majority of knees as positive or better.
Kim et al. [34]Prospective comparativeOAComparative study: following arthroscopic debridement, group 1 received an intra-articular injection of SVF; group 2 received an intra-articular injection of SVF+fibrin glue as a scaffoldIKDC, Tegner, 2nd-lookarthroscopic ICRS grading54 (56 knees): 37 vs. 17
Age: 57.5 vs. 57.7
Sex: M-F: 14-23vs. 8-9
K-L: I-II
29.2 vs. 27.3 monthsIKDC and Tegner activity scores significantly improved in both groups but showed no significant difference. Statistical significance between the two groups was observed in ICRS grades, with the SVF group being more positive. A higher BMI resulted in less positive outcomes.
Koh et al. [32]Prospective comparativeOAComparative study: intra-articularinjection of SVF+PRP vs. only PRP prior to performing open-wedge high tibial osteotomyLysholm, KOOS, VAS, and femorotibial angle. Arthroscopic evaluation44 (23 vs. 21)
Age: 52.3 vs. 54.2
Sex: M-F: 6-17vs. 5-16
K-L: I-III
24-25 months (mean: 24.4)Lysholm, VAS score, and KOOS improved statistically in both groups. KOOS improvements were statistically greater in the SVF group. No difference in the preoperative and postoperative femorotibial angles. SVF group displayed greater fibrocartilage coverage.
Koh et al. [35]RetrospectiveOAArthroscopic debridement+administration of SVF to articular chondral lesionsIKDC score and Tegner activity scale, 2nd-look arthroscopic ICRS grading35 (37 knees)
Age: 48-69
Sex: M-F: 14-21
K-L: I-II
24-34 months (mean: 26.5)IKDC and Tegner activity scores significantly improved. Patients reported high satisfaction scores. It was noted that a higher BMI resulted in less positive outcomes.
Bui et al. [31]ProspectiveOAIntra-articular SVF+PRP injectionVAS and Lysholm scores, MRI21
Age: ≤18
Sex: N/A
K-L: II-II
6 monthsStatistically significant improvement in VAS and Lysholm scores. MRI analysis showed partial regeneration and thickening of articular cartilage.
Koh et al. [38]RetrospectiveOAInfrapatellar SVF+PRP, intra-articularinjection+weekly PRP injection for 2 weeksWhole-organ MRI, WOMAC, VAS, and Lysholm scores18
Age: 41-69
Sex: M-F: 6-12
K-L: III-IV
24-26 months (mean: 24.3)Significant decrease of WOMAC, VAS, and Lysholm scores. Significant decrease of whole-organ MRI scores. Extent of improvement was directly correlated with the amount of MSCs injected.

NPS: numerical pain scale; OKS: Oxford Knee Score; LEFS: Lower Extremity Functionality Score; VAS: visual analog scale; OARSI: Osteoarthritis Research Society International; ICOAP: Intermittent and Constant Osteoarthritis Pain; WOMAC: Western Ontario and McMaster Universities Arthritis Index; TKA: total knee arthroplasty; IKDC: International Knee Documentation Committee; KOOS: Knee injury and Osteoarthritis Outcome Score; MACI: Matrix-induced Autologous Chondrocyte Implantation; ROM: range of motion; ICRS: International Cartilage Regeneration & Joint Preservation Society; PeCaBoo: percutaneous cartilage-bone interface optimization system; dGEMRIC: delayed gadolinium-enhanced magnetic resonance imaging of cartilage.