Effects of malalignment and disease activity on osteophyte formation in knees of rheumatoid arthritis patients

Abstract

Purpose: Rheumatoid arthritis (RA) patients with secondary osteoarthritis (OA) in a knee joint following a total knee arthroplasty (TKA) procedure have been increasing. Here, we investigated osteophyte formation in knee joints of RA patients and associated factors. Methods: We retrospectively examined findings of 35 knees in 30 RA patients (26 females, 4 males; mean age: 63.0 years; median disease duration: 15 years) who underwent TKA, including preoperative anteroposterior view radiographs of the knee joint. Using the ImageJ software package, osteophyte size in the medial femur (MF), medial tibia (MT), lateral femur (LF), and lateral tibia (LT) regions was also determined. Results: The mean femorotibial angle was 179°, while Larsen grade was 2 in 1, 3 in 12, 4 in 18, and 5 in 2 patients. Osteophyte sizes in the MF, MT, LF, and LT regions were 37.2, 17.0, 27.2, and 4.57 mm2, respectively, and significantly greater in the medial compartment (MC; MF+MT) than the lateral compartment (LC; LF+LT) ( p < 0.001). In varus cases, osteophyte size in the MC was significantly larger than normal and valgus cases ( p = 0.0016). Furthermore, osteophyte size in the MC was negatively correlated with the inflammatory markers C-reactive protein ( r = −0.492, p = 0.0027) and erythrocyte sedimentation rate ( r = −0.529, p = 0.0016), whereas that in the LC was negatively correlated with disease activity ( r = −0.589, p = 0.0023). Conclusion: Our results suggest that alignment and disease activity influence osteophyte formation in RA patients, with secondary OA a more prominent symptom in RA patients with controlled inflammation.

Increasing trend of radiographic features of knee osteoarthritis in rheumatoid arthritis patients before total knee arthroplasty

“…A low CRP level was found to be a significant factor for the classification into the OA-like RA group in the current study. Our result was consistent with that of a previous study reporting the correlation between the low CRP level in RA patients and the frequent existence of osteophytes or the amount of osteophytes in knee radiographs before TKA 10 , 12 . A high CRP level is one of the well-proven prognostic factors for RRP, which is generally defined based on the van der Heijde-modified Sharp score composed of erosion and joint space narrowing scores 20 – 22 , 28 .…”

“…A few previous studies investigating radiographs of RA patients have reported a correlation between low levels of C-reactive protein (CRP) and increased formation of periarticular osteophytes 10 – 12 . Although these studies suggested that RA patients with well-controlled disease activity tended to show the radiographic characteristics of OA, they focused only on osteophytes, ignoring other characteristics such as subchondral bone sclerosis, cysts, joint space narrowing.…”

Analgesic effects and arthritic changes following intra-articular injection of diclofenac etalhyaluronate in a rat knee osteoarthritis model

“…Coronal cross-sectional images parallel to the bony axis of the tibia and through the center of the articular surface were produced on CT and evaluated using the Larsen classification [ 28 ], commonly applied in rheumatoid arthritis. Two blinded orthopedic surgeons evaluated and scored the sections according to the degree of joint deformity.…”