Semin Musculoskelet Radiol 2020; 24(S 01): S1-S8
DOI: 10.1055/s-0040-1709551
Scientific Presentations and Posters
Georg Thieme Verlag KG Stuttgart · New York

Quantitative 3-T MRI Outcome Evaluation after Spongiosa-augmented MACI at the Knee: The Importance of Subchondral Bone Parameters

Matthias Jung
1   Department of Diagnostic and Interventional Radiology, Medical Center – University of Freiburg, Faculty of Medicine, Freiburg, Germany
,
Stefan Ruschke
2   Department of Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
,
Dimitrios C. Karampinos
2   Department of Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
,
Christian Holwein
3   Department of Orthopaedic Sports Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
4   Department of Trauma and Orthopaedic Surgery, BG Unfallklinik Murnau, Murnau, Germany
,
Joachim Suchowierski
5   Department of Orthopaedic Sports Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
,
Alexandra S. Gersing
2   Department of Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
,
Fabian Bamberg
1   Department of Diagnostic and Interventional Radiology, Medical Center – University of Freiburg, Faculty of Medicine, Freiburg, Germany
,
Pia M. Jungmann
1   Department of Diagnostic and Interventional Radiology, Medical Center – University of Freiburg, Faculty of Medicine, Freiburg, Germany
› Author Affiliations
Further Information

Publication History

Publication Date:
25 March 2020 (online)

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Introduction We evaluated the association of quantitative magnetic resonance (MR) imaging parameters of the subchondral bone with MR morphological and clinical outcomes after osteochondral transplantation at the knee.

Material and Methods Bilateral 3-T MRI of the knee was performed in 21 patients (n = 16 male) 2.5 years after spongiosa-augmented matrix-associated chondrocyte implantation (MACI) at the femoral condyle for the treatment of osteochondral defects. Morphological MR sequences were assessed using magnetic resonance observation of cartilage repair tissue (MOCART) scores. T2 relaxation time measurements were performed at the cartilage repair tissue site (CR-T2), at the underlying subchondral bone marrow (BM-T2), and at identical sites of the contralateral knee. Single-voxel MR spectroscopy (BM water fraction, BM unsaturation fraction) was acquired at the subchondral BM, at the central femoral condyle, and at the contralateral knee. Presence of pain and Tegner scores were noted.

Results The mean defect size was 4.9 ± 1.9 cm2. At follow-up, 9 of 21 patients were asymptomatic. Perfect defect filling was achieved in two thirds of cases. MOCART scores (mean ± standard deviation: 75.4 ± 16.5) did not indicate pain (p = 0.426). However, knee pain was present in 85.7% of patients with deep bony defects (odds ratio: 8.0). The underlying bone marrow edema volume (p = 0.001) was larger, and there were deeper bony defects (p = 0.010) in subjects with cartilage repair tissue underfilling as compared with subjects with perfect defect filling. Relative CR-T2 was higher in hypertrophic repair tissue (p = 0.002). Higher BM-T2 correlated significantly with higher BM water fractions (p < 0.001) and nonsignificantly with lower unsaturated lipid fractions (p = 0.052). Higher BM-T2 (p = 0.032) and higher BM water fractions (p = 0.040) correlated significantly with more clinical symptoms (Tegner score).

Conclusion Integrity of the subchondral bone is essential for optimal outcomes after osteochondral transplantation.