Knee articular cartilage injury treatment with matrix-induced autologous chondrocyte implantation (MACI): correlation at 24 and 120 months between clinical and radiological findings using MR arthrography

Abstract

Objective: To evaluate the long-term evolution of matrix-induced autologous chondrocyte implantation (MACI) with magnetic resonance (MR) arthrography and verify the correlation between radiological and clinical findings.

Materials and methods: Twenty-six patients (20 m/6f) were diagnosed with knee chondral injuries and treated with MACI implantation. Each patient received MR arthrography and clinical examination at mid-term (range 22-36 months) and long term (range 96-194 months) after surgery. MR arthrography was performed with dedicated coil and a 1.5-Tesla MR unit. The modified MOCART scale was used to evaluate the status of chondral implants. Implant coating, integration to the border zone, and the surface and structure of the repaired tissue were evaluated. Presence of bone marrow oedema was evaluated. The Cincinnati Knee Rating System (CKRS) was used for clinical assessment.

Results: At long term, 4/26 patients had complete alignment; 5/26 had a complete integration of the margins; in 4/26 cases, the implant surface was undamaged; in 14/26 cases, the reparative tissue was homogeneous. In 9/26 cases, the implant showed isointense signal compared to articular cartilage, while the presence of subchondral bone oedema was documented in 19/26 cases. The average radiological score decreased from 59.2 (mid-term) to 38.6 (long term). The average clinical score decreased from 8.9 to 8.3.

Conclusions: Decrease in clinical results was not significant (0.6 points p = .06), but mMOCART scores decreased significantly (p = .00003). Although imaging studies showed deterioration of the grafts, the patients did not have significant clinical deterioration (231/250).

Keywords: Arthrography; Articular; Cartilage; Chondrocytes; Follow-up studies; Magnetic resonance imaging.

Fig. 1

Cincinnati Knee Rating System Diagram. It represents an accurate rating of knee symptoms on a four-level scale rating scales assessing pain, swelling, partial giving way, and full giving way based on the patient perception of the overall condition of the knee. This scale was firstly proposed by Barber-Westin S. D.; Noyes, F. R.; McCloskey, J. W.: Rigorous statistical reliability, validity, and responsiveness testing of the Cincinnati Knee Rating System in 350 subjects with uninjured, injured, or anterior cruciate ligament-reconstructed knees. Am J Sports Med 27:402–416, 1999

Fig. 2

Flow-chart selection of patients in the study

Fig. 3

a Sagittal SE T1-weighted image acquired after intra articular administration of paramagnetic contrast media at mid-term. The MACI implant is evident at the posterior aspect of the internal femoral condyle (arrow). It obtained a MOCART score of 50 and a Cincinnati score of 9. The cartilage filling is incomplete, <50% of the adjacent cartilage (arrowheads). b The same patient repeated the exam at long term with the same parameters. The image shows deterioration of the MACI implant with a MOCART score of 40 and a Cincinnati score of 8. Subchondral bone is, in fact, exposed (arrowheads) with trabecular bone signal intensity modification compatible with bone marrow oedema (asterisk). c Sagittal SE T1-weighted image acquired after intra articular administration of paramagnetic contrast media at mid-term. The MACI implant is evident at the lateral patellar articular facet (arrow). It obtained a MOCART score of 50 and a Cincinnati score of 9. The cartilage filling is complete (arrowheads). d The same patient repeated the exam at long term with the same parameters. The implant showed good stability with a MOCART score of 60 and a Cincinnati score 9. At long term, the cartilage filling remained complete, without radiological signs of MACI degeneration (arrowheads)

Fig. 4

Distribution of modified mMOCART subgroup scores at mid-term follow-up (range: 22–36 months). A, B, C, D, E and F represent the categories analysed in the mMocart classification and are listed in Table 2. (A) Filling of defect (degree of defect repair and filling of the defect). (B) Integration to context: border zone. (C) Surface of the repair tissue. (D) Structure of the repair tissue. (E) Signal intensity of the repair tissue (dual T2-FSE Fat-Suppression). (F) Subchondral bone

Fig. 5

Distribution of modified mMOCART subgroup scores at long-term follow-up; range 96–194 months). A, B, C, D, E and F represent the categories analysed in the mMocart classification and are listed in Table 2. (A) Filling of defect (degree of defect repair and filling of the defect). (B) Integration to context: border zone. (C) Surface of the repair tissue. (D) Structure of the repair tissue. (E) Signal intensity of the repair tissue (dual T2-FSE Fat-Suppression). (F) Subchondral bone

Fig. 6

a, b A 39-year-old man treated with MACI of the internal tibial plate at mid-term with mMOCART score of 70 and Cincinnati score of 9. a Sagittal oblique FSE PD fat-saturated image shows non-structural incongruence of the chondral surface. b Sagittal oblique SE T1-weighted image. No contrast enhancement. c, d A 29-year-old woman treated with MACI of the internal femoral condyle at mid-term with mMOCART score of 25, Cincinnati score 9. c Sagittal oblique FSE PD fat-saturated image shows structural incongruence of the chondral surface (arrow) and subchondral bone oedema. d Sagittal oblique SE T1-weighted image. Contrast enhancement in the subchondral bone (arrow) [images obtained with “Unit1”]

Fig. 7

a, b A 28-year-old man treated with MACI of the internal tibial plate at long term with mMOCART score of 25, Cincinnati score 9. a Sagittal oblique FSE PD fat-saturated image shows structural incongruence of the chondral surface (arrowhead). b Sagittal oblique SE T1-weighted image. Contrast enhancement of the chondral implant (arrowhead). c, d A 47-year-old man treated with MACI of the internal femoral condyle at long-term with mMOCART score of 20, Cincinnati score 5. c Sagittal oblique FSE PD fat-saturated image shows structural incongruence of the chondral surface (arrow) and the presence of subchondral bone oedema with incomplete integration to the border zone. d Sagittal oblique SE T1-weighted image. Contrast enhancement of the chondral implant (arrow) [images obtained with “Unit1”]