Altered Subchondral Bone Mineral Density in Painful Knee Osteoarthritis Without Cysts: A Comparative Analysis of Lateral and Medial Regions

Objectives ​ This study aims to elucidate the mechanisms underlying pain generation and progression in knee osteoarthritis (KOA) by investigating alterations in proximal tibial subchondral bone mineral density (BMD) among individuals experiencing painful KOA without subchondral cysts, utilizing three-dimensional (3D) bone densitometry. Methods ​ A prospective, single-center data collection was conducted at the 960th Hospital of the Joint Logistics Support Force of the PLA. We employed a 3D bone densitometry technique to assess BMD in specific regions. Knee pain was evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Based on WOMAC scores, the knees of each patient were categorized into a moderate-severe pain group and a mild pain group. We explored the correlation between BMD and pain and analyzed differences among various pain subgroups. Results ​ Computed tomography (CT) imaging of 84 knees from 42 patients revealed a significant association between BMD and pain. The moderate-to-severe pain group exhibited higher BMD in the lateral compartment compared to the mild pain group. Statistically significant differences were observed in 0-2.5 mm lateral-posterior, 2.5-5.0 mm lateral-anterior, 5.0-7.5 mm medial-posterior, and 7.5-10.0 mm lateral-posterior. Conclusions ​ The altered subchondral bone density of the proximal tibia may play a pivotal role in the pathogenesis of KOA-related pain in patients.