To date, few studies have been published reporting the 5-year follow-up of clinical and radiological outcomes for chondral defects treated with matrix-induced autologous chondrocyte implantation (MACI). A significant improvement in clinical and radiological outcomes after treatment of symptomatic, traumatic chondral defects of the knee with the MACI implant will be maintained up to 5 years after surgery. Case series; Level of evidence, 4. A prospective evaluation of the MACI procedure was performed in 21 patients with chondral defects of the knee. After the MACI procedure, patients were clinically assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS), the Tegner-Lysholm score, the International Knee Documentation Committee (IKDC) Subjective Knee Form, and the modified Cincinnati score at years 1, 2, and 5. The quality of repair tissue was assessed by magnetic resonance imaging using the magnetic resonance observation of cartilage repair tissue (MOCART) score at months 3 and 6 and years 1, 2, and 5. Significant improvements (P < .05) were observed for all 5 KOOS subcategories at year 1 and were maintained through year 5 in 90.5% of patients (19/21). Treatment failure occurred in only 9.5% of patients (2/21). Significant improvements (P < .05) from baseline to year 5 were also observed for the IKDC score (30.1 to 74.3), the modified Cincinnati score (38.1 to 79.6), and the Tegner-Lysholm activity score (1.8 to 4.3). Similarly, the MOCART score significantly improved (P < .001) from baseline to year 5 (52.9 to 75.8). After 5 years, complete filling (83%) and integration (82%) of the graft were seen in the majority of patients. Signs of subchondral bone edema were still present in 47% of patients at 5 years. No product-specific adverse events were reported over the 5-year follow-up period. Patients treated with a MACI implant demonstrated significant clinical improvement and good quality repair tissue 5 years after surgery. The MACI procedure was shown to be a safe and effective treatment for symptomatic, traumatic chondral knee defects in this study.

It is unclear whether matrix-associated autologous chondrocyte transplantation (MACT) results in objective and subjective clinical improvements at 10 years after surgery. Matrix-associated autologous chondrocyte transplantation will result in clinical and radiological improvements in patients with symptomatic, traumatic chondral defects of the knee joint. Case series; Level of evidence, 4. A total of 16 patients with chondral defects of the knee were treated with MACT between November 2000 and April 2002 and evaluated for up to 10 years after the intervention. The International Knee Documentation Committee (IKDC) form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner activity score, Brittberg score, Noyes sports activity rating scale, and visual analog scale (VAS) for pain as well as 3-T magnetic resonance imaging (MRI) using the magnetic resonance observation of cartilage repair tissue (MOCART) score and functional evaluation by the limb symmetry index (LSI) formed the basis of this study. The Friedman test and the Wilcoxon signed-rank test were performed for a comparison between all time points and 2 separate time points, respectively. If significant differences were revealed, a Bonferroni adjustment to the α level was applied so that P values <.007 (<.05/7) were regarded as significant in the paired comparisons. Significant improvements (P < .05) from baseline to 120 months postoperatively were observed for the IKDC score (mean, 44.1 ± 26.9 to 59.0 ± 27.4), Noyes sports activity rating score (mean, 37.7 ± 30.1 to 62.1 ± 31.3), and KOOS Quality of Life and Pain subscores, whereas no statistically significant improvement was detected for the Brittberg score, Tegner activity score, or VAS score. After 5 years, a slight downward tendency of all clinical scores was evident. After 10 years, the mean MOCART score was 70.4 ± 16.1. Complete filling of the defect was observed in 73.9% of cases, and osteophytes were present in 78.3%. In 65.2% of the cases, a subchondral bone edema 1 cm was seen. The mean LSI for the single-legged hop test was 95.6% ± 16.2% and for the triple hop test for distance was 91.3% ± 12.2%. The mean VAS score for self-perceived stability was 60.2 ± 3.5 (range, 0-9.5) for the injured and 60.7 ± 3.8 (range, 0-10) for the uninjured leg. No adhesions or effusions were seen regarding the clinical and radiological outcomes. The significantly improved results on 3 outcome measures after 10 years suggest that MACT represents a suitable option in the treatment of local cartilage defects in the knee.

Background: A range of scaffolds is available from various manufacturers for cartilage repair through matrix-associated autologous chondrocyte transplantation (MACT), with good medium- to long-term results. Purpose: To evaluate clinical and magnetic resonance imaging (MRI) outcomes 2 years after MACT on the knee joint using the Novocart 3D scaffold based on a bilayered collagen type I sponge. Study Design: Case series; Level of evidence, 4. Methods: Of 28 initial patients, 23 were clinically and radiologically evaluated 24 months after transplantation. Indications for MACT were chondral or osteochondral lesions on the knee joint with a defect size >2 cm ² , no instability, and no malalignment (axis deviation <5°). Then, MRI was performed on a 3-T scanner to assess the magnetic resonance observation of cartilage repair tissue (MOCART) and 3-dimensional (3D) MOCART scores. A variety of subjective scores (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Noyes sports activity rating scale, Tegner activity scale, and visual analog scale [VAS] for pain) were used for clinical evaluation. Results: Two years after MACT, the MRI evaluation showed a mean MOCART score of 73.2 ± 12.4 and a 3D MOCART score of 73.4 ± 9.7. Clinical results showed mean values of 69.8 ± 15.2 for the IKDC; 51.6 ± 21.2, 86.5 ± 13.9, 54.5 ± 23.6, 65.0 ± 8.0, and 91.5 ± 10.6 for the KOOS subscales (Quality of Life, Pain, Sports and Recreation, Symptoms, and Activities of Daily Living, respectively); 77.5 ± 12.7 for the Noyes scale; 4.4 ± 1.6 for the Tegner activity scale; and 1.8 ± 1.7 for the VAS, with statistically significant improvement in all scores other than KOOS-Symptoms. Conclusion: Undergoing MACT using the Novocart 3D scaffold is an applicable method to treat large focal chondral and osteochondral defects, with good short-term clinical and radiological results.

Trauma, malposition and age‐related degeneration of articular cartilage often result in severe lesions that do not heal spontaneously. Many efforts over the last centuries have been undertaken to support cartilage healing, with approaches ranging from symptomatic treatment to structural cartilage regeneration. Microfracture and matrix‐associated autologous chondrocyte transplantation (MACT) can be regarded as one of the most effective techniques available today to treat traumatic cartilage defects. Research is focused on the development of new biomaterials, which are intended to provide optimized physical and biochemical conditions for cell proliferation and cartilage synthesis. New attempts have also been undertaken to replace chondrocytes with cells that are more easily available and cause less donor site morbidity, e.g. adipose derived stem cells (ASC). The number of in vitro studies on adult stem cells has rapidly increased during the last decade, indicating that many variables have yet to be optimized to direct stem cells towards the desired lineage. The present review gives an overview of the difficulties of cartilage repair and current cartilage repair techniques. Moreover, it reviews new fields of cartilage tissue engineering, including stem cells, co‐cultures and platelet‐rich plasma (PRP). Copyright © 2011 John Wiley & Sons, Ltd.