Qualitative and Quantitative Measures in the Infrapatellar Fat Pad in Older Adults: Associations with Knee Pain, Radiographic Osteoarthritis, Kinematics, and Kinetics of the Knee

Zhengming Wang; Jiehang Lu; Zhengyan Li; Yuanyuan Wang; Haiya Ge; Min Zhang; Rui Wang; Yong Gu; Lipeng Ding; Woxing Ren; Zhibi Shen; Guoqing Du; Yufeng Wu; Hongsheng Zhan

doi:10.1016/j.acra.2024.02.013

Qualitative and Quantitative Measures in the Infrapatellar Fat Pad in Older Adults: Associations with Knee Pain, Radiographic Osteoarthritis, Kinematics, and Kinetics of the Knee

Acad Radiol. 2024 Feb 26:S1076-6332(24)00083-7. doi: 10.1016/j.acra.2024.02.013. Online ahead of print.

Authors

Zhengming Wang¹, Jiehang Lu¹, Zhengyan Li¹, Yuanyuan Wang², Haiya Ge¹, Min Zhang¹, Rui Wang³, Yong Gu⁴, Lipeng Ding¹, Woxing Ren¹, Zhibi Shen¹, Guoqing Du⁵, Yufeng Wu⁶, Hongsheng Zhan⁷

Affiliations

¹ Shi's Center of Orthopedics and Traumatology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China; Institute of Traumatology & Orthopedics, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China.
² Shanghai University of Traditional Chinese Medicine, Shanghai, China.
³ Guanghua Clinical Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai, China; Department of Orthopedic Surgery, Shanghai Guanghua Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai, China.
⁴ Translational Medical Innovation Center, Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Zhangjiagang, Jiangsu, China.
⁵ Shi's Center of Orthopedics and Traumatology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
⁶ Zhongshan Hospital of Traditional Chinese Medicine Affiliated to Guangzhou University of Traditional Chinese Medicine, Zhongshan, Guangdong, China.
⁷ Shi's Center of Orthopedics and Traumatology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China; Institute of Traumatology & Orthopedics, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China. Electronic address: zhanhongsheng@shutcm.edu.cn.

PMID: 38413312
DOI: 10.1016/j.acra.2024.02.013

Abstract

Rationale and objectives: The purpose of this study is to delineate cross-sectional associations between qualitative and quantitative measures of the infrapatellar fat pad (IPFP) and knee symptoms, structure, kinematics, and kinetics in older adults.

Methods: Ninety eligible subjects (90 knees, mean age 54.0 years, 68.9% female) were examined at our center. We used T2-weighted fat-suppressed magnetic resonance imaging (MRI) to evaluate signal intensity alteration, maximum sagittal area, and depth of the IPFP. Symptomatic osteoarthritis (SOA) was a pain subscale score greater than 0 on the Western Ontario McMaster Osteoarthritis Index. A Kellgren-Lawrence grade ≥ 2 identified incident radiographic osteoarthritis (iROA). Three-dimensional gait data were employed to analyze knee joint kinematics and kinetics. Correlation and regression analyzes assessed associations between IPFP measurements and SOA, iROA, kinematics, and kinetics.

Results: There were strong and positive associations between IPFP signal intensity alteration and both SOA and iROA in multivariable regression analyzes [OR (95% CI): 2.849 (1.440 to 5.636), 2.356 (1.236 to 4.492), respectively]. Conversely, a significant negative correlation was observed between IPFP maximum area and flexion angle [B (95%CI): - 1.557 (-2.549 to -0.564)]. Moreover, adjusting for covariates did not reveal any significant correlation between IPFP parameters and other indicators (P > 0.05, respectively).

Conclusion: IPFP signal intensity alteration and area were associated with knee clinical symptoms, structural abnormalities, and flexion angle in adults over 40, respectively. These findings suggest that IPFP may be a crucial imaging biomarker in early and middle knee osteoarthritis.

Keywords: Infrapatellar fat pad; Kinematics; Kinetics; Osteoarthritis; Structure; Symptom.