Enhanced microfracture using acellular scaffolds improves results after treatment of symptomatic focal grade III/IV knee cartilage lesions but current clinical evidence does not allow unequivocal recommendation

  • Cristiana Branco da CunhaEmail author
  • Renato Andrade
  • Tiago Rafael Veloso
  • David A. Learmonth
  • João Espregueira-Mendes
  • Rui A. Sousa



To systematically analyse post-operative outcomes following enhanced microfracture procedures in focal cartilage injuries of the knee.


Database searches were conducted in PubMed, EMBASE and Cochrane Library databases up to 30 November 2018, for clinical studies in humans that assessed surgical outcomes of enhanced microfracture procedures in focal cartilage injuries of the knee. The clinical, functional and imaging outcomes were assessed and summarized. The MINORS scale was used to assess the methodological quality of the studies included.


Ten studies were included comprising a total of 331 patients (mean age of 37.0 ± 5.5 years, body mass 25.2 ± 1.7 kg m2, 56% male and 42% left knee), 278 femoral condyle chondral defects (147 medial, 35 lateral and 78 undefined) and 43 chondral defects distributed by the tibial plateau, patella and femoral trochlea. The chondral defects were mostly Outerbridge grade III or IV and the mean defect size was 3.2 ± 0.6 cm2. Studies consistently demonstrated significant improvement in the patient-reported outcome measures from baseline to final follow-up. Overall, imaging outcomes showed inconsistent results. Treatment-related adverse events were poorly reported.


Enhanced microfracture techniques significantly result in improved patient-reported outcome measures over the MCID, but provide inconsistent imaging results. Current clinical evidence does not allow for unequivocal recommendation of enhanced microfracture to treat symptomatic focal grade III/IV knee cartilage lesions.

Level of evidence



Enhanced microfracture Microfracture Cartilage Chondral Osteochondral 





Minimal clinically important difference


The autologous matrix-induced chondrogenesis


Chondroitin sulphate


Magnetic resonance imaging


Magnetic Resonance Observation of Cartilage Repair Tissue


International Knee Documentation Committee Subjective Knee Form


Western Ontario and McMaster Universities Arthritis Index


Knee Injury and Osteoarthritis Outcome Score


Visual Analogue Scale


Authors’ contributions

CBC, TRV and RA designed and implemented the systematic review protocol, CBC, TRV and RA collected, analyzed and interpreted the data collected, CBC, TRV and RA critically reviewed the scientific content of the manuscript, CBC, RA, JEM and RAS drafted the manuscript, and all authors (CBC, RA, TRV, DAL, JEM and RAS) have read, reviewed and given final approval for the version to be published.


The authors declare that there was no funding for this study.

Compliance with ethical standards

Conflict of interest

JEM and RAS are shareholders, and CBC, TRV, DAL and RAS are current employees of Stemmatters, Biotecnologia e Medicina Regenerativa SA. Stemmatters is currently developing a proprietary medical device to be used in the context of enhanced microfracture surgical treatment. Stemmatters is actively pursuing patents related to the content of the manuscript. This manuscript was not influenced by personal or financial relationship with Stemmatters or any other third party.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Supplementary material

167_2019_5832_MOESM1_ESM.docx (16 kb)
Supplementary material 1 (DOCX 16 kb)
167_2019_5832_MOESM2_ESM.docx (18 kb)
Supplementary material 2 (DOCX 17 kb)


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Copyright information

© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2020

Authors and Affiliations

  1. 1.Stemmatters, Biotecnologia e Medicina Regenerativa SABarco, GuimarãesPortugal
  2. 2.Clínica do Dragão, Espregueira-Mendes Sports Centre-FIFA Medical Centre of ExcellencePortoPortugal
  3. 3.Dom Henrique Research CentrePortoPortugal
  4. 4.Faculty of SportsUniversity of PortoPortoPortugal
  5. 5.ICVS/3B’s-PT Government Associate LaboratoryBraga/GuimarãesPortugal
  6. 6.Life and Health Sciences Research Institute (ICVS), School of MedicineUniversity of MinhoBragaPortugal

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