RA膝関節での骨棘サイズに影響する因子の検討

抄録

Objective: Cases of secondary osteoarthritis (OA) in knee joints of patients with rheumatoid arthritis (RA) following prior total knee arthroplasty (TKA) are increasing. This study aimed to investigate the morphology of osteophytes in the knee joints of patients with RA.

Methods: We analyzed 35 knees in 30 patients with RA (26 women, 4 men; mean age 62.9 years; median disease duration 15 years) who underwent TKA from January 2013 to December 2016, including preoperative anteroposterior view radiographs of the knee joint. Using the Image-J open source software package, osteophyte size in the medial femur (MT), medial tibia (MT), lateral femur (LF), and lateral tibia (LT) regions were determined.

Results: The mean femoro-tibial angle (FTA) was 178°, while Larsen grade was 2 in one, 3 in 12, 4 in 18, and 5 in two patients, respectively. Osteophyte size in the MF, MT, LF, and LT regions was 57.5, 29.6, 23.5, and 13.3 mm², respectively. Medial compartment size (MF+MT) was significantly larger in varus alignment (P=0.035), while lateral compartment size (LF+LT) correlated with disease activity (R=−0.582, P<0.01).

Conclusion: Our results suggest that secondary osteoarthritis can progress in RA and disease activity may influence osteophyte size.