Chemical composition of the infrapatellar fat pad of swine

Quantitative MRI reveals infrapatellar fat pad changes after running a marathon

Background

Marathon running, while offering health benefits, is associated with a high incidence of knee injuries. The infrapatellar fat pad (IFP) plays a critical role in knee joint homeostasis and injury mitigation. This study investigated IFP adaptations to the acute stress of marathon running using quantitative magnetic resonance imaging (MRI).

Methods

Fourteen amateur marathon runners (12 male, two female) were prospectively enrolled and underwent 3.0T MRI (GE SIGNA Architect) one week before and after the marathon. Left knee imaging included MAGiC and IDEAL-IQ sequences. MAGiC sequences provide T1, T2, and proton density (PD) maps. IDEAL-IQ sequences yield fat fraction (FF), representing the relative amount of fat within the IFP, and the transverse relaxation rate (R2*) within the IFP. IFP volume and maximum cross-sectional area were quantified. Two experienced radiologists independently analyzed the images using dedicated software. Inter-observer reliability for quantitative MRI measurements was assessed using intraclass correlation coefficients (ICCs). Paired t-tests were used to compare pre- and post-marathon measurements of T1, T2, FF, R2* values, IFP volume and maximum cross-sectional area. Pearson correlation analysis explored relationships between changes in IFP parameter changes and participant characteristics. P < 0.05 was considered statistically significant for all analyses.

Results

Post-marathon, IFP FF significantly increased (p < 0.05), while IFP volume significantly decreased (p < 0.05), T1 and T2 values showed a decreasing trend. IFP appeared morphologically compressed post-marathon. A significant negative correlation was found between FF change and both body weight and body mass index (BMI) (p < 0.05).

Conclusions

This study provides novel evidence of robust IFP adaptation to marathon running, characterized by increased FF and potential fluid shifts, suggesting enhanced cushioning and load dissipation. These findings highlight the importance of considering individual biomechanics in understanding IFP function and injury susceptibility. Future research should clarify the clinical implications of these adaptations for runner injury prevention and rehabilitation.

Dietary fatty acid content and thickness of plantar pads in gilts

The objective of this study was to test a diet enriched in the most abundant components of foot fat pads (oleic and palmitic acid) to increase its thickness in gilts. We evaluated the effects of two oleic and palmitic acid dietary concentrations (control and test) and three treatment durations (35, 45, and 65 d) on 116 gilts (Landrace × Large White), all 180-d-old and slaughtered at the end of the study. Both test and control diets contained 5.9% total fat. The control diet contained 0.9% oleic acid and 0.6% palmitic acid; the test diet contained 1.9% and 1.2%, respectively. Body weight (BW), backfat (BF), lateral, and medial plantar pad thickness from the left rear leg were measured. No significant differences were detected for BW or BF between the test and control groups. The lateral pad was always thicker than the medial one (P < 0.001). No significant difference for plantar pad thickness was detected for the 35 d treatment. For the other treatments, thickness increased with respect to the control group (P < 0.01); the percentage of increase ranged from 20.8% (lateral side, 45 d treatment) to 37.8% (lateral side, 65 d treatment). Its effects on foot health must still be demonstrated.

Role of infrapatellar fat pad in pathological process of knee osteoarthritis: Future applications in treatment

It has been found that obese people have a higher proportion in suffering from osteoarthritis (OA), not only in the weight-bearing joints like knee and hip joints, even in non-weight-bearing joints such as hand joints. One of the reasons is because the large amount of adipose tissue secretes some factors, which can promote the occurrence of arthritis. As an important structure of the knee joint, the infrapatellar fat pad (IPFP) is actually a piece of adipose tissue. The aim of this review is to offer a comprehensive view of the anatomy and physiological characteristics of IPFP and its relationship with the pathological process of OA, indicating the important function of IPFP in OA. At the same time, with the development of adipose derived stem cells in the treatment of OA, owing to its special advantages, the IPFP is becoming a kind of important, minimally invasive fat stem cell source, providing a new approach for the treatment of OA. We hope that this review will offer an overview of all published data regarding the IPFP and will indicate novel directions for future research.