IMAGING-BASED ANALYSIS OF STRUCTURAL PRESERVATION IN EXPERIMENTAL OSTEOARTHRITIS

Preclinical osteoarthritis (OA) studies frequently report structural degeneration; however, comparative evaluation of therapeutic interventions using imaging-based endpoints remains limited. In particular, whether different acupuncture modalities exert distinct effects on joint structure and subchondral bone microarchitecture has not been systematically assessed.

1) To compare the effects of multiple acupuncture modalities on joint structural integrity using imaging-based outcomes. 2) To determine whether laser acupuncture provides better preservation of cartilage and subchondral bone. 3) To evaluate modality-specific differences in bone microarchitecture remodeling.

OA was induced via intra-articular monosodium iodoacetate in male Sprague-Dawley rats (n = 48 per study; n = 8/group). Two experimental arms were conducted:(1) comparative modalities (manual acupuncture, electroacupuncture, bee venom acupuncture, and laser acupuncture), and (2) wavelength-specific invasive laser acupuncture (650 nm and 830 nm). All treatments were applied at GB34 under standardized protocols. Structural outcomes were assessed using micro-computed tomography (Quantum GX2; 90 kV, 88 ìA, voxel size 20 ìm) and histological analysis (Safranin-O/Fast Green; OARSI scoring). Micro-CT parameters included bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp), as well as meniscal ossicle formation.

Acupuncture modalities demonstrated distinct effects on joint structure. Laser acupuncture and electroacupuncture produced the greatest preservation of cartilage integrity and subchondral bone architecture compared to OA controls (p < 0.001). Micro-CT analysis revealed that laser-treated groups exhibited improved trabecular organization and reduced pathological bone remodeling. Meniscal ossicle formation, a marker of OA progression, was significantly reduced in laser-treated animals (p < 0.006). In wavelength-specific analysis, 830 nm laser acupuncture showed superior structural outcomes, with increased BV/TV (34.85 ± 1.21, p < 0.01) and reduced trabecular separation (p < 0.05), indicating enhanced preservation of bone microarchitecture. Histological findings were consistent with imaging data, demonstrating reduced cartilage degeneration and improved matrix preservation in laser-treated groups.

Acupuncture modalities differentially modulate structural joint degeneration in experimental OA. Imaging-based analyses demonstrate that laser acupuncture, particularly at 830 nm, provides better preservation of cartilage and subchondral bone microarchitecture.