Bone marrow lesions and serum NTx predict varus change in medial proximal tibial angle in early knee osteoarthritis.

Abstract

We investigated the influence of abnormal magnetic resonance imaging findings and serum bone metabolism on varus deformity progression in the proximal tibia of women without radiographic abnormalities. A hundred and forty-six participants without radiographic knee osteoarthritis were assessed using a 5-year longitudinal analysis of the Iwaki cohort. Participants were classified into a normal or an early radiographic knee osteoarthritis group based on the Knee Injury and Osteoarthritis Outcome Score, clinical examinations, and bilateral radiographs. The medial proximal tibial angle was measured on knee radiographs. Abnormal imaging findings were assessed using the whole-organ magnetic resonance imaging scoring method. Serum bone metabolic markers were also measured. Thirty-eight of the participants (26 %) were classified into the early radiographic knee osteoarthritis group. Variation in the medial proximal tibial angle was greater in participants with early radiographic knee osteoarthritis and bone marrow lesions than in those without either of them (p < 0.001). Varus deformity in the proximal tibia negatively correlated with tartrate-resistant acid phosphatase-5b (r = -0.192, p = 0.022) and N-telopeptide of type I collagen (r = -0.031, p < 0.001). Linear regression revealed that varus deformity was associated with bone marrow lesions (β = -0.252, p = 0.002), N-telopeptide of type I collagen (β = -0.249, p = 0.002), and early radiographic knee osteoarthritis (β = -0.163, p = 0.037). Early radiographic knee osteoarthritis with bone marrow lesions and a high bone absorption metabolism are potential risk factors for the progression of varus deformity in the proximal tibia.