2023, Vol. 27 ›› Issue (31): 5035-5039

Distribution characteristics of bone mass in different parts of postmenopausal women with knee osteoarthritis

Chen Jianchao, Song Huiping   

Abstract: BACKGROUND: There is still a big controversy about the interaction between knee osteoarthritis and osteoporosis. Patients with knee osteoarthritis often present with changes in bone mineral density (BMD). The relationship between the BMD of the knee joint and the BMD of the lumbar spine and hip is unclear.
OBJECTIVE: To investigate the distribution and correlation of BMD in the lumbar spine, femoral neck, and knee joint of patients with knee osteoarthritis.
METHODS: 150 postmenopausal women with primary knee osteoarthritis were selected to measure the BMD of the lumbar spine, femoral neck, and ipsilateral knee joint. Then the knee joint was divided into six regions of interest (ROI), which were marked as R1-R6, with R1 representing the medial side of proximal tibia, R2 representing the lateral side of proximal tibia, R3 representing the proximal tibia (R3=R1+R2), R4 representing the medial side of distal femur, R5 representing the lateral side of distal femur and R6 representing the distal femur (R6=R5+R4). According to the K-L classification, all the patients were divided into grade 0 group (33 cases), grade I-II group (61 cases), and grade III group (56 cases). The BMD of each ROI was compared with the BMD of the lumbar spine and femoral neck, and then the BMD of different ROIs was compared in pairs. The correlation between the BMD of each ROI and the BMD of the lumbar spine and femoral neck was analyzed.
RESULTS AND CONCLUSION: (1) The BMD of R2, R4, R5, and R6 in the grade III group was lower than that in the grade 0 group (P < 0.05). The BMD of the femoral neck, R2, and R3 in the grade III group was lower than that in the grade I-II group (P < 0.05). (2) The BMD of each ROI of the knee joint in the three groups was ranked as R5 > R6 > R4 > (R1, R2, and R3). The BMD of R1 was lower than that of R2 in the grade 0 group (P < 0.05). (3) In grade 0 patients, the BMD of R2, R5, and R6 was positively correlated with the BMD of the lumbar spine and femoral neck (P < 0.05), while the BMD of R1 and R3 was only positively correlated with the BMD of the lumbar spine (P < 0.05). In grade I-II patients, the BMD of each ROI of the knee joint was positively correlated with the BMD of the lumbar spine and femoral neck (P < 0.05). In grade III patients, the BMD of R1 and R3 was positively correlated with the BMD of the lumbar spine and femoral neck (P < 0.05), while the BMD of R2, R4, R5, and R6 was only positively correlated with the BMD of the femoral neck (P < 0.05). (4) All these findings suggest that there are differences in the BMD of different ROIs of the knee joint, and the BMD of the lateral side of distal femur is the highest. With the progression of knee osteoarthritis, the BMD of the femoral neck and the BMD of the knee joint except the medial side of proximal tibia are on the decline, and the BMD of different parts of the knee joint is correlated with the BMD of the lumbar spine and ipsilateral femoral neck.

Key words: knee joint, osteoarthritis, osteoporosis, bone mineral density, correlation, menopause, lumbar spine, femoral neck