Background Complex meniscal lesions often require meniscectomy with favorable results in the short term but a high risk of early osteoarthritis subsequently. Partial meniscectomy treated with meniscal substitutes may delay articular cartilage degeneration. Purpose To evaluate the status of articular cartilage by T2 mapping after meniscal substitution with polyurethane scaffolds enriched with mesenchymal stem cells (MSC) and comparison with acellular scaffolds at 12 months. Methods Seventeen patients (18-50 years) with past meniscectomies were enrolled in 2 groups: (1) acellular polyurethane scaffold (APS) or (2) polyurethane scaffold enriched with MSC (MPS). Patients in the MPS group received filgrastim to stimulate MSC production, and CD90+ cells were obtained and cultured in the polyurethane scaffold. The scaffolds were implanted arthroscopically into partial meniscus defects. Concomitant injuries (articular cartilage lesions or cartilage lesions) were treated during the same procedure. Changes in the quality of articular cartilage were evaluated with T2 mapping in femur and tibia at 12 months. Results In tibial T2 mapping, values for the MPS group increased slightly at 9 months but returned to initial values at 12 months ( P > 0.05). In the APS group, a clear decrease from 3 months to 12 months was observed ( P > 0.05). This difference tended to be significantly lower in the APS group compared with the MPS group at the final time point ( P = 0.18). In the femur, a slight increase in the MPS group (47.8 ± 3.4) compared with the APS group (45.3 ± 4.9) was observed ( P > 0.05). Conclusion Meniscal substitution with polyurethane scaffold maintains normal T2 mapping values in adjacent cartilage at 12 months. The addition of MSC did not show any advantage in the protection of articular cartilage over acellular scaffolds ( P > 0.05).

Methods Seventeen patients aged 18 to 55 years with symptomatic full-thickness cartilage lesions on either patella or trochlea were treated with matrix autologous chondrocyte implantation (MACI) or microfracture (MF). Both procedures combined with unloading/realigning techniques. Clinical assessment and T2-mapping were evaluated at 48-months. Results Clinically results from pre-op to 48-months improved significantly in MACI and MF for Lysholm ( p = 0.001, p = 0.001), IKDC-S ( p = 0.001, p = 0.002), KOOS-P ( p = 0.000, p = 0.002), KOOS-DLA ( p = 0.002, p = 0.003), KOOS-Sports/Rec ( p = 0.000, p = 0.004), KOOS-QoL ( p = 0.000, p = 0.003), KOOS-symptoms ( p = 0.001, p = 0.020), and Kujala ( p = 0.000, p = 0.01), respectively. Tegner was significant between baseline and 48 months only for MACI ( p < 0.008) compared with MF ( p = 0.25). No significant difference was observed between groups for any score at 3, 12, 24, and 48-months ( p > 0.05). T2-mapping values improved significantly over time in MACI compared with MF at 24 months (39.35 vs. 50.44, p = 0.007) and 48 months (36.54 vs. 48.37, p = 0.005). When comparing control values to MACI at 12-m ( p = 0.714), 24-m ( p = 0.175), and 48-m ( p = 0.097), no significant difference was found. MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score comparison gave no statistical difference between groups. Conclusions Clinically both techniques improved significantly over time. However, quantitative assessment showed that only newly formed tissue with MACI technique improves significantly since 12-months and maintains stable values compared with native cartilage until 48-month follow-up. MF results were never comparable to those native values. Level of evidence II.

No abstract

RESUMENPropósito: evaluar los resultados clínicos y por imagen (mapeo T2) del implante artroscópico de condrocitos autólogos en matriz encapsulada (ICAME) en lesiones condrales en patela a un seguimiento de 4 años. Métodos: se incluyeron 16 pacientes de 18 a 55 años de edad (promedio 34,37 ± 2,59) con lesión(es) condral(es) focalizadas en patela. Se les realizó el ICAME mediante artroscopia y en algunos casos se adicionó alguna de las técnicas de realineación o descompresión patelofemoral. El seguimiento clínico se evaluó mediante escalas de rodilla y la calidad del tejido de reparación se cuantificó por mapeo T2 comparándose con una zona de cartílago sano adyacente. Resultados: el tiempo de relajación del tejido de reparación (ROI-6, 54,81 ± 7,07) fue significativamente mayor al del cartílago control (ROI-3, 35,44 ± 5,51) a los 3 meses de postoperados (p < 0,001). A los 18 meses dichos valores disminuyeron sin observarse diferencia significativa entre el control (34,42 ± 3,66) y la zona de reparación (38,80 ± 6,71) (p = 0,0863) manteniéndose estable hasta ABSTRACT A new arthroscopic technique of matrix-encapsulated autologous chondrocyte implantation (MEACI) in patella: clinical and T2 mapping evaluation at 4 years of follow-up Purpose: to evaluate clinical and imaging (T2 mapping) outcomes of the arthroscopic technique of matrix-encapsulated autologous chondrocytes implantation (MEACI) in chondral lesions in patella at a follow-up of 4 years. Methods: we included 16 patients aged 18 to 55 years old (average 34.37 ± 2.59) with chondral lesion(s) localized in the patella. They underwent the arthroscopic technique of MEACI and in some cases techniques of patellofemoral realignment or decompression. Clinical follow-up was assessed using knee scores and repair tissue quality was quantified by T2-Mapping and comparing to an adjacent zone of native cartilage. Results: repair tissue relaxation time (ROI-6, 54.81 ± 7.07) was significantly higher than that of the control cartilage (ROI-3, 35.44 ± 5.51) at 3 months postoperatively (p < 0.001). At 18 months, these values decreased without a significant dif- OriginalesUna nueva técnica artroscópica de implante de condrocitos autólogos en matriz encapsulada (ICAME) en patela: evaluación clínica y por mapeo T2 a 4 años de seguimiento