Department of Orthopaedic Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan.
Department of Orthopaedic Surgery, University of Health and Welfare Hospital, 537-3 Iguchi, Nasu-shiobara, Tochigi, 329-2763, Japan.
J Orthop Res. 2019 Mar;37(3):593-600. doi: 10.1002/jor.24201. Epub 2019 Jan 3.
Infrapatellar fat pad has been implicated in knee osteoarthritis. We examined whether infrapatellar fat pad volume is associated with quantitative cartilage changes using magnetic resonance imaging T1ρ mapping. Fifty-eight knees of knee pain patients (19 men, 39 women, mean age 57.0 [range 29-85] years) who were conservatively managed and had >1 T1ρ mapping images taken over time were evaluated. We used three slices from the medial femoral and tibial cartilage; areas showing T1ρ values <130 ms and >50 ms were designated as having cartilage degeneration. Cases were categorized into three groups: Improvement, No Change, and Deterioration. Fat-suppressed T2-weighted sagittal magnetic resonance images were used for measuring infrapatellar fat pad volume. Percent change in infrapatellar fat pad volume was -5.01 ± 5.66%, -2.06 ± 4.92%, and 0.05 ± 6.09% in the Improvement (n = 22), No Change (n = 22), and Deterioration (n = 14) groups, respectively, demonstrating significantly reduced infrapatellar fat pad volume in the Improvement group (p < 0.05). Multivariate regression analyses revealed that the percent change in infrapatellar fat pad volume significantly affected T1ρ change category independent of age, sex, follow-up period, baseline infrapatellar fat pad volume, and Kellgren-Lawrence grade. Infrapatellar fat pad volume and obesity or body weight change showed no correlation. Infrapatellar fat pad volume was reduced in patients with improved quantitative cartilage assessment on magnetic resonance imaging T1ρ mapping. This is the first study demonstrating associations between quantitative cartilage changes and infrapatellar fat pad morphological changes, suggesting a detrimental role of infrapatellar fat pad volume in articular cartilage degeneration. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
髌下脂肪垫与膝关节骨关节炎有关。我们通过磁共振 T1ρ 成像检查髌下脂肪垫体积与定量软骨变化的相关性。评估了 58 例膝关节疼痛患者（19 名男性，39 名女性，平均年龄 57.0 岁[范围 29-85 岁]）的膝关节，这些患者均采用保守治疗，且在一段时间内有>1 次 T1ρ 成像检查。我们使用内侧股骨和胫骨软骨的 3 个切片；T1ρ 值<130ms 和>50ms 的区域被指定为软骨退变。病例分为三组：改善、无变化和恶化。髌下脂肪垫的矢状位磁共振 T2 加权脂肪抑制图像用于测量髌下脂肪垫体积。改善组（n=22）、无变化组（n=22）和恶化组（n=14）髌下脂肪垫体积的百分比变化分别为-5.01±5.66%、-2.06±4.92%和 0.05±6.09%，改善组髌下脂肪垫体积明显减少（p<0.05）。多变量回归分析表明，髌下脂肪垫体积的百分比变化独立于年龄、性别、随访时间、基线髌下脂肪垫体积和 Kellgren-Lawrence 分级，显著影响 T1ρ 变化类别。髌下脂肪垫体积与肥胖或体重变化无相关性。髌下脂肪垫体积在磁共振成像 T1ρ 图谱上定量软骨评估改善的患者中减少。这是第一项表明定量软骨变化与髌下脂肪垫形态变化之间存在关联的研究，表明髌下脂肪垫体积在关节软骨退变中起有害作用。
