Bone Mineral Density Around the Knee Joint: Correlation With Central Bone Mineral Density and Associated Factors

Chan Yoon; Moon Jong Chang; Chong Bum Chang; Jee Won Chai; Hyunseok Jeong; Min Kyu Song; Jae Hoon Shin; Seung-Baik Kang

doi:10.1016/j.jocd.2018.07.005

Bone Mineral Density Around the Knee Joint: Correlation With Central Bone Mineral Density and Associated Factors

J Clin Densitom. 2020 Jan-Mar;23(1):82-91. doi: 10.1016/j.jocd.2018.07.005. Epub 2018 Jul 19.

Authors

Chan Yoon¹, Moon Jong Chang¹, Chong Bum Chang², Jee Won Chai³, Hyunseok Jeong¹, Min Kyu Song¹, Jae Hoon Shin¹, Seung-Baik Kang¹

Affiliations

¹ Department of Orthopaedic Surgery, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Seoul, South Korea.
² Department of Orthopaedic Surgery, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Seoul, South Korea;. Electronic address: ccbknee@gmail.com.
³ Department of Radiology, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Seoul, South Korea.

PMID: 30120026
DOI: 10.1016/j.jocd.2018.07.005

Abstract

Introduction: The aims of this study were to (1) assess the bone mineral density (BMD) around the knee joint, (2) determine the correlation between central and knee BMDs, and (3) investigate the factors associated with BMD around the knee joint in patients with knee osteoarthritis (OA).

Methodology: This cross-sectional study included 122 patients who underwent total knee arthroplasty. Central and knee dual-energy X-ray absorptiometry was performed preoperatively. BMD at 6 regions of interest (ROIs) around the knee joint were measured, and their correlations with central BMD were determined using Spearman's correlation analysis. Lower limb alignment, severity of OA, body mass index (BMI), preoperative functional and pain scores were assessed to elucidate the factors associated with knee BMD using linear regression analysis.

Results: Around the knee joint, BMD was the lowest at the distal femoral metaphysis and lateral tibial condyle. Knee BMD was significantly correlated with central BMD. However, the correlation coefficients varied by the ROI. Additionally, multivariate analysis revealed different associations with respect to the regions around the knee joint. Varus alignment of the lower limb was associated with increased BMD of the medial condyles and decreased BMD of lateral condyles. High grade OA was a protective factor; it was associated with increased BMD at the lateral condyles of the femur and tibia. Higher BMI was an independent protective factor in all ROIs around the knee joint except the lateral femoral condyles. Lower functional level was not associated with decreased BMD, whereas a higher pain score was significantly associated with lower BMD at the proximal tibial metaphysis.

Conclusions: Knee BMD was significantly correlated with central BMD. However, the correlations varied with the regions around the knee joint probably due to their independent association with the alignment of the lower limb, severity of OA, BMI, and preoperative pain level.

Keywords: Bone mineral density; dual-energy X-ray absorptiometry; osteoarthritis; osteoporosis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Absorptiometry, Photon
Aged
Aged, 80 and over
Arthroplasty, Replacement, Knee
Body Mass Index
Bone Density*
Cross-Sectional Studies
Female
Femur / anatomy & histology
Femur / pathology
Humans
Knee Joint / anatomy & histology*
Linear Models
Male
Middle Aged
Osteoarthritis, Knee / pathology
Osteoarthritis, Knee / surgery
Severity of Illness Index
Tibia / anatomy & histology
Tibia / pathology