3T MRI Evaluation of the Stability of Autologous Matrix-induced Chondrogenesis Membrane Ex Vivo: A Human Cadaver Study

Milstrey A; Schindler P; Schuelke C; Evers J; Raschke MJ; Ochman S

Abstract

The surgical treatment of osteochondral lesions of the talus (OLT) is still challenging. Treatment success is often evaluated via MRI. However, the accuracy of MRI in evaluating the repair tissue is not precise. The purpose of the study was to evaluate the visibility and assessability of the membrane after autologous matrix-induced chondrogenesis (AMIC) via a modern 3 Tesla (3T) MRI. Eight Bilayer I/III collagen membranes (Chondro-Gide, Geistlich, Wollhusen, Switzerland) were implanted in 1 cm2 osteochondral lesions on the medial or lateral talar shoulder in fresh-frozen human specimens. After cyclic testing, the stability of the membrane was assessed clinically. 3T-MRI scans were performed with sagittal and coronal fat-suppressed proton density sequences, and MR arthrography was performed with a coronal fat-suppressed T1-SE sequence. Analysis was performed using a 4-point Likert scale. Clinical evaluation revealed an excellent stability of the membrane after cyclic biomechanical testing (7 of 8 membranes stable). Image quality (median score 1.0; mean 1.1 +/- 0.3) and interrater reliability (ICC=0.9, P<0.001) were good to excellent. The analysis showed a poor visibility of the membrane with still significantly better visualization of the patch in the lateral talus compared with the medial side (mean score lateral 3.5 +/- 0.8 vs. medial 4.0 +/- 0.0, P=0.027). Postoperative MRI scans are not specific enough to evaluate the acute consolidation process after cartilage repair surgery. Along with the limited long-term outcome prediction of 3T MRI scans, the development of a more precise diagnostic assessment remains an important goal in orthopedic research.