Association between bone marrow lesions and bone mineral density of the proximal tibia in end-stage osteoarthritic knees

Abstract

This retrospective cross-sectional study investigated the association between bone marrow lesions (BMLs) and bone mineral density (BMD) in the proximal tibia of end-stage osteoarthritic knees from a large patient sample. Overall, 1308 end-stage osteoarthritic knees were enrolled before total knee arthroplasty. The preoperative range of motion was recorded. Bone mineral density in the medial tibial plateau (MTP), lateral tibial plateau (LTP), and metaphysis were measured using dual-energy X-ray absorptiometry. The MTP/LTP, MTP/metaphysis, and LTP/metaphysis ratios were calculated. BMLs were scored using a whole-organ magnetic resonance imaging scoring system. The relationship between BMD and BML scores was investigated using linear regression analysis. The highest BMD was 0.787 ± 0.176 g/cm² at the MTP, followed by 0.676 ± 0.180 g/cm² and 0.572 ± 0.145 g/cm² at the metaphysis and LTP, respectively. The prevalence of BMLs was 90.4% and 24.2% in the MTP and LTP, respectively. In women, higher BML scores at the MTP were positively correlated with the BMD of the MTP (p < 0.001, r = 0.278), MTP/LTP (p < 0.001, r = 0.267), and MTP/metaphysis ratios (p < 0.001, r = 0.243). Regression analysis showed that higher BML scores in the MTP were correlated with higher BMD in the MTP (p < 0.001) and lower BMD in the LTP (p < 0.001). High BML scores in the MTP were positively associated with high BMD in the MTP, which also induced the medial to lateral imbalance of BMD in the proximal tibia.

Figure 1

Regions of interest (ROIs) in the proximal tibia for evaluating bone mineral density. ROI of the medial tibial plateau (R1): center of the medial tibial plateau 10 mm distal to the subchondral bone on the anterior–posterior scout image. ROI of the lateral tibial plateau (R2): the center of the lateral tibial plateau, 10 mm distal to the subchondral bone on the anterior–posterior scout image. ROI of the metaphysis (R3): the center of the tibia, 50 mm distal to the joint line of the proximal tibia.

Figure 2

Bone marrow lesion scores using magnetic resonance imaging. Sagittal and coronal views of short TI inversion recovery (STIR) images of the knee are taken. Bone marrow lesions (BMLs) are scored using the whole magnetic resonance imaging score, where A is scored as grade 0, B as grade 1, C as grade 2, and D as grade 3 in the medial femoral condyle.

Figure 3

Bone mineral densities among different age groups in both sexes. Mean and standard deviations of the bone mineral density of the medial tibial plateau (A), lateral tibial plateau (B), and metaphysis (C) in men and those of the medial tibial plateau (D), lateral tibial plateau (E), and metaphysis (F) in women are shown. A p-value below 0.05 was considered significant in the comparison of the following age groups: < 59 group (*), 60–65 group (^†), 65–69 group (^‡), and 70–74 group (^#).

Figure 4

Prevalence of bone marrow lesions among different age groups in both sexes. Prevalence of bone marrow lesions (BMLs) at the medial femoral condyle (MFC) (A), medial tibial plateau (MTP) (B), and medial femorotibial (FT) joint (C), lateral femoral condyle (LFC) (D), lateral tibial plateau (LTP) (E), and lateral FT joint (F) in men and women are shown.

Figure 5

Correlation among medial to lateral balance of bone mineral density (BMD), bone marrow lesion (BML) score, and femorotibial angle (FTA). Scatter plot among BMD or BML score in medial tibia plateau (MTP), lateral tibia plateau (LTP), and MTP/LTP ratio and FTA are shown. Spearman’s correlation coefficients were calculated.