Evaluation of Subchondral Bone Marrow Lipids of Acute Anterior Cruciate Ligament (ACL)-Injured Patients at 3 T

Abstract

Rationale and Objectives The objectives of this study were to investigate the changes in compartment-specific subchondral bone marrow lipids of femoral–tibial bone in acute anterior cruciate ligament (ACL)-injured patients compared to that of healthy volunteers and patients with osteoarthritis (OA) (Kellgren–Lawrence [KL] grade 2–3). Materials and Methods A total of 55 subjects were recruited in the study and subdivided into three subgroups: 17 healthy controls (4 females, 13 males; mean age = 41 ± 16, age range 24–78 years), 17 patients with acute ACL injury (3 females, 14 males; mean age = 30 ± 11, age range 18–61 years), and 21 patients with KL2–3 OA (12 females, 9 males; mean age = 65 ± 12, age range 44–89 years). Routine clinical proton density–weighted fast spin echo images in sagittal (without fat saturation), axial, and coronal (fat saturation) planes were acquired on a 3 T clinical scanner for cartilage morphology using Whole-Organ Magnetic Resonance Imaging Score grading. A voxel of 10 × 10 × 10 mm3 was positioned in the medial and lateral compartments of the tibia and femur for proton magnetic resonance spectroscopy measurements using the single voxel stimulated echo acquisition mode pulse sequence. All proton magnetic resonance data were processed with Java-based magnetic resonance user interface. Wilcoxon rank sum test and mixed model two-way analysis of variance were performed to determine significant differences between different compartments and examine the effect of ACL injury, OA grade and compartment, and their interactions. Results The index of unsaturation in lateral tibial compartment in ACL-injured patients was significantly higher (P < .05) than all compartments except lateral femoral in patients with KL2–3 OA. Significantly lower values (P < .05) were also identified in saturated lipids at 2.03 ppm in all compartments in ACL-injured patients than those of all compartments in patients with KL2–3 OA. Conclusions The preliminary results suggest that the indices of unsaturation in the lateral tibial compartment and the peaks of saturated lipids at 1.3 and 2.03 ppm in medial tibial compartment may be clinically useful to characterize subchondral bone marrow among healthy controls, acute ACL-injured patients, and patients with OA.

Quantification of bone marrow water and lipid composition in anterior cruciate ligament-injured and osteoarthritic knees using three-dimensional magnetic resonance spectroscopic imaging

“…Despite this, Li et al [12] and Wang et al's more recent study [21] interestingly both observed ACL-injured knees to have a higher UI than their OA counterparts, suggesting the possibility of different biochemical changes occurring within ACL and OA BMEL. This study saw a non-significant increase and decrease in UI in the BMEL and non-BMEL regions of ACL-injured knees compared to those with OA, respectively.…”

“…These results are congruent with observations from a previous cross-sectional study [12] and indicate pathological changes in bone marrow within BMEL regions. One study conducted by Wang et al [15] found a general decrease in UI in subjects with mild OA compared to control, and another [21] found no significant differences in UI between ACL-injured and control knees or between OA and control knees. However, Wang et al's studies employed single-voxel MRS and focused on the UI of different compartments within the knee joint as opposed to BMEL and non-BMEL regions.…”

“…One study found a general decrease in the lipid unsaturation index in subjects with mild OA compared to control [15]. Another noted that anterior cruciate ligament (ACL)-injured subjects had a significantly increased index of unsaturation compared to subjects with OA; they also reported no significant differences in the lipid unsaturation index between ACL-injured and control knees or between OA and control knees [21]. MRSI can provide further spatial information of these biochemical changes.…”

MRI texture analysis of subchondral bone at the tibial plateau

“…Previous MR studies have demonstrated alterations in microstructural trabecular morphometry measurements between volunteers and individuals with OA [13,14], and that such measurements correlate well with severity of OA [15]. Proposed mechanisms of alteration in SB architecture include entry of inflammatory infiltrates via vascular channels in the SB [37] and increased deposition of subchondral marrow lipids [38].…”

Quantitative 3-T Magnetic Resonance Imaging After Matrix-Associated Autologous Chondrocyte Implantation With Autologous Bone Grafting of the Knee: The Importance of Subchondral Bone Parameters

“…Only a few studies have assessed the use of MRS for BM of the knee. 32,59,61,62 The value of MRS for subchondral BM after cartilage repair surgery has not been studied.…”