Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg, Austria.
Arthritis Care Res (Hoboken). 2011 Mar;63(3):311-9. doi: 10.1002/acr.20370.
To study the longitudinal rate of (and sensitivity to) change of knee cartilage thickness across defined stages of radiographic osteoarthritis (OA), specifically healthy knees and knees with end-stage radiographic OA.
One knee of 831 Osteoarthritis Initiative participants was examined: 112 healthy knees, without radiographic OA or risk factors for knee OA, and 719 radiographic OA knees (310 calculated Kellgren/Lawrence [K/L] grade 2, 300 calculated K/L grade 3, and 109 calculated K/L grade 4). Subregional change in thickness was assessed after segmentation of weight-bearing femorotibial cartilage at baseline and 1 year from coronal magnetic resonance imaging (MRI). Regional and ordered values (OVs) of change were compared by baseline radiographic OA status.
Healthy knees displayed small changes in plates and subregions (±0.7%; standardized response mean [SRM] ±0.15), with OVs being symmetrically distributed close to zero. In calculated K/L grade 2 knees, changes in cartilage thickness were small (<1%; minimal SRM -0.22) and not significantly different from healthy knees. Knees with calculated K/L grade 3 showed substantial loss of cartilage thickness (up to -2.5%; minimal SRM -0.35), with OV1 changes being significantly (P < 0.05) greater than those in healthy knees. Calculated K/L grade 4 knees displayed the largest rate of loss across radiographic OA grades (up to -3.9%; minimal SRM -0.51), with OV1 changes also significantly (P < 0.05) greater than in healthy knees.
MRI-based cartilage thickness showed high rates of loss in knees with moderate and end-stage radiographic OA, and small rates (indistinguishable from healthy knees) in mild radiographic OA. From the perspective of sensitivity to change, end-stage radiographic OA knees need not be excluded from longitudinal studies using MRI cartilage morphology as an end point.
研究膝关节软骨厚度在特定的放射学骨关节炎（OA）阶段（包括健康膝关节和终末期放射学 OA 膝关节）的纵向变化率（和对变化的敏感性）。
对 831 名骨关节炎倡议参与者的一只膝关节进行了检查：112 只健康膝关节，无放射学 OA 或膝关节 OA 的危险因素，719 只放射学 OA 膝关节（310 只计算 Kellgren/Lawrence [K/L] 分级 2，300 只计算 K/L 分级 3，109 只计算 K/L 分级 4）。在基线和磁共振成像（MRI）的 1 年时，通过对负重股骨胫骨软骨进行分割，评估厚度的亚区变化。根据基线放射学 OA 状况比较了区域和有序变化值（OV）。
健康膝关节的板层和亚区变化较小（±0.7%；标准化反应均值[SRM] ±0.15），OV 接近对称分布于零附近。在计算的 K/L 分级 2 膝关节中，软骨厚度的变化较小（<1%；最小 SRM -0.22），与健康膝关节无显著差异。计算的 K/L 分级 3 膝关节显示出大量的软骨厚度损失（高达-2.5%；最小 SRM -0.35），OV1 变化明显大于健康膝关节（P < 0.05）。计算的 K/L 分级 4 膝关节在放射学 OA 分级中显示出最大的损失率（高达-3.9%；最小 SRM -0.51），OV1 变化也明显大于健康膝关节（P < 0.05）。
基于 MRI 的软骨厚度在中晚期放射学 OA 膝关节中显示出较高的损失率，在轻度放射学 OA 膝关节中损失率较低（与健康膝关节无显著差异）。从对变化的敏感性来看，使用 MRI 软骨形态作为终点的纵向研究无需排除终末期放射学 OA 膝关节。
