Relationship between the change in infrapatellar fat pad thickness assessed using ultrasonography and anterior knee pain on squatting after anterior cruciate ligament reconstruction

• Published in: Journal of medical ultrasonics (2001) Vol. 50; no. 2; pp. 237 - 243
• Main Authors: Shiraishi, Ryo, Ueda, Shinichiro
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.04.2023; Springer; Springer Nature B.V
• Subjects: Activities of daily living; Adipose Tissue - diagnostic imaging; Adolescent; Adult; Anterior Cruciate Ligament Injuries - surgery; Anterior Cruciate Ligament Reconstruction - methods; Body mass index; Consent; Female; Females; Humans; Imaging; Joints (anatomy); Knee; Knee Joint - diagnostic imaging; Knee Joint - surgery; Knee pain; Ligaments; Male; Males; Medicine; Medicine & Public Health; Original Article–Orthopedics; Original –Orthopedics; Orthopedic surgery; Pain; Radiology; Reconstructive surgery; Sports injuries; Supine position; Tendons; Thickness; Ultrasonic imaging; Ultrasonography; Ultrasound; Ultrasound imaging; Young Adult; United States > US; Anterior cruciate ligament reconstruction; Ultrasonography; Infrapatellar fat pad
• ISSN: 1346-4523; 1613-2254; 1613-2254
• DOI: 10.1007/s10396-023-01300-3

Purpose Anterior knee pain (AKP) may occur after anterior cruciate ligament (ACL) reconstruction. The present study investigated the relationship between the change in infrapatellar fat pad (IFP) thickness assessed using ultrasonography (US) and AKP on squatting in patients after ACL reconstruction. Methods Patients were enrolled 3 months after ACL reconstruction using the bone-tendon-bone (BTB) technique. Subjects were divided into the AKP group (numerical rating scale [NRS] score ≥ 1) and control group (NRS score < 1) using a NRS of pain on squatting, and intergroup comparisons were performed. On US evaluation, measurement angles of the knee joint were 0° and 30° in the supine position. The IFP between the femoral intercondylar notch and patellar tendon was measured on short-axis images. The changes in IFP thickness were calculated from values measured at different angles of the knee joint. Results Twenty-one patients (mean age 24.9 ± 9.3 years) were included in the present study: 12 in the AKP group (9 males, 3 females) and nine in the control group (5 males, 4 females). A significant difference in the change in IFP thickness at 3 months was observed between the AKP and control groups (0.67 ± 0.44 mm vs. 1.84 ± 0.34 mm, p < 0.001). There was a negative correlation between the change in IFP thickness and the NRS score (r = − 0.720, p < 0.001) in reconstructed knees. Conclusion A smaller change in IFP thickness assessed using US after ACL reconstruction was identified as a factor contributing to AKP on squatting.