Flexibility of infrapatellar fat pad affecting anterior knee pain 6\xa0months after anterior cruciate ligament reconstruction with hamstring autograft

Takashi Kitagawa,Rikuto Yoshimizu,Yasushi Takata,Mitsuhiro Kimura,Junsuke Nakase,Hiroyuki Tsuchiya,Kengo Shimozaki,Kazuki Asai

doi:10.1038/s41598-020-78406-y

Takashi Kitagawa, Rikuto Yoshimizu + Show 6 more

Open Access

https://doi.org/10.1038/s41598-020-78406-y

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Journal: Scientific Reports	Publication Date: Dec 1, 2020
Citations: 6	License type: open-access

Affiliation: Kanazawa University, Shinshu University

Abstract

This study aimed to identify factors affecting anterior knee pain (AKP) after anterior cruciate ligament reconstruction (ACLR) with hamstring tendon autograft using ultrasonography. Forty-two patients were evaluated by ultrasound, 6 months after ACLR. The thickness of the superficial part of the infrapatellar fat pad was measured, as well as the thickness change ratio between the two angles. Color Doppler evaluated the rate of blood flow in the fat pad. AKP was assessed with the Kujala Scale. The correlations between AKP and age, body mass index, the thickness change ratio, and the grade of increased blood flow were examined. Independent variables showing significant correlations with AKP were used for multiple linear regression analysis. There were significant correlations between AKP and age (r = − 0.68), body mass index (r = − 0.37), the thickness change ratio of the fat pad (r = 0.73) and the grade of increased blood flow (r = − 0.42), respectively. Age and the thickness change ratio of the fat pad affected the AKP score (R2 = 0.56). After ACLR, older age and a decrease in the thickness change ratio of the superficial area of the infrapatellar fat pad appear to affect post-operative AKP after 6 months.

Highlights

This study aimed to identify factors affecting anterior knee pain (AKP) after anterior cruciate ligament reconstruction (ACLR) with hamstring tendon autograft using ultrasonography
Findings indicate that the dynamics of the superficial part of the infrapatellar fat pad (IPFP) during knee flexion decreased after ACLR
We hypothesized that the thickness change ratio of the superficial part of the IPFP during knee flexion would affect the AKP after ACLR using hamstring tendon (HT) autograft, due to some underlying pathologies[9,10,11,12]

Summary

Introduction

This study aimed to identify factors affecting anterior knee pain (AKP) after anterior cruciate ligament reconstruction (ACLR) with hamstring tendon autograft using ultrasonography. After ACLR, older age and a decrease in the thickness change ratio of the superficial area of the infrapatellar fat pad appear to affect post-operative AKP after 6 months. One study which investigated post-operative factors in patients with AKP following HT harvesting, reported that increased blood flow in the infrapatellar fat pad (IPFP) was independently associated with the presence of anterior knee symptoms (OR 5.0, 95% CI 1.3–19.9)[4]. Another study investigated the relationship between the range of motion of the knee joint and the dynamics of the IPFP in patients after A CLR13 These recent insights may help to explain the decrease in dynamics of the IPFP, in the superficial part of the IPFP, which may cause IPFP impingement or change the pressure of the infrapatellar tissue. We hypothesized that the thickness change ratio of the superficial part of the IPFP during knee flexion would affect the AKP after ACLR using HT autograft, due to some underlying pathologies[9,10,11,12]

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