Table 2 Regenerative treatment options for meniscal lesions

Augmentation of meniscal suture and meniscus reconstruction by intraarticular microfracturing

+ Easy to perform

+ Adhesion of stem cells at lesion site

- Uncertain effect

- Low concentration of stem cells at defect site

Augmentation of meniscal suture or meniscus cell-free reconstruction (e.g. Actifit) by locally applied growth factors (e.g. PRP)

+ Application directly at meniscal lesion site

+ High concentration at lesion site

+ Support of intrinsic healing potential

+ One-step-procedure

- Preparation time

- Short term effect at lesion site

- Uncertain local effect

Augmentation of meniscal suture by locally applied MSCs (e.g. bone marrow derived)

+ High potential differentiation

+ Application directly at meniscal lesion site

+ Support of meniscus regeneration

+ Use of autologous cells

+ Potentially one-step-procedure

- Preparation time

- Regulatory burden

- Missing knowledge of repair mechanisms

Intraarticular injection of MSCs/growth factors

+ Adhesion at lesion site

+ Easy to perform

- Uncertain effect

- Low concentration of stem cells at lesion site

- Harvesting and preparation prior to application

- Side effects in the knee joint beside the defect site

Intravascular injection of MSCs

+ Adhesion at lesion site

- Uncertain effect

- Low concentration of stem cells at lesion site

- Harvesting and preparation prior to application

- Side effects in other areas besides the defect

- No clinical experience

Implantation of MSC loaded carrier/scaffold at meniscal defect site

+ Potential for treatment of meniscal critical size defects

+ Application directly at meniscal defect site

+ Option for pre-differentiation of MSC/carrier construct

+ Use of autologous cells

- High costs

- Missing knowledge of repair mechanisms

- Necessity of cell expansion prior to implantation/two-step-procedure

- No clinical experience