Patient profiling in cartilage regeneration of the knee: mid term result and prognostic factor.

Objectives: Autologous chondrocyte implantation (ACI) was developed two decades ago, and both the production of a hyaline-like articular surface and a satisfactory clinical outcome have been documented; the development of the Matrix-assisted Autologous Chondrocyte Transplantation (MACT) techniques further improved the potential of this regenerative treatment approach with bothbiological and surgical advantages. However, indication criteria of these procedures are still controversial. The aim of this study is to determine patient characteristics that could influence the results, in order to improve them and help to select patients that may benefit from this regenerative treatment with a better clinical outcome. Methods: 194 consecutive patients, 142 men and 52 women with a mean age of 29.0 ± 10.4 years, affected by knee chondral lesions, were enrolled and treated with implantation of a hyaluronic acid based bioengineered tissue (141 underwent an arthroscopic procedure, in the other cases a mini-open approach was used). All the patients were evaluated prospectively yearly for a minimum follow-up of 5 years with IKDC, EQ-VAS, and Tegner scores. Complications, failures, and patient satisfaction were also documented. Results: A statistically significant improvement was observed in all scores from the basal evaluation to the final follow-up. The IKDC subjective score increased from 39.0 ± 14.1 to 76.0 ± 21.6 at 5 years (p\0.0005); a similar improvement was documented with the EQ-VAS score, passing from 58.1 ± 19.7 to 83.8 ± 15.3 (p\0.0005), and also the activity level evaluated with Tegner score showed a marked improvement, from 1.7 ± 1.2 to 5.1 ± 2.5 (p\0.0005), even if without achieving the pre-injury level (6.7 ± 2.0, p\0.0005). A better outcome was obtained in young active men affected by traumatic chondral lesions of the medial femoral condyle, whereas the worst results were found in degenerative lesions, in lesions of other joint sites, or when previous surgery had been performed. Conclusions: This study demonstrates the influence of various factors on clinical outcome at 5 years follow-up after MACT. Age, sex, activity level, as well as etiology, site and previous patient’s history, are important aspects to be considered when treating knee chondral lesions. The understanding of all influencing factors and their mechanism of action will help to better select the treatment strategy and to further improve the potential and clinical outcome of cartilage regenerative procedures.