Abstract Information 
Abstract ID
20260047
Category
Knee: ACL
Preferable Presentation
Both
Title
ASSOCIATIONS OF CIRCULATING MYOKINES WITH MORPHOLOGICAL AND FUNCTIONAL RECOVERY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A PROSPECTIVE COHORT STUDY
Author
  • Full Name: XIN YANG
  • Affiliation/Institution: The Chinese University of Hong Kong
  • Country: Hong Kong S.A.R.

  • Full Name: TIANYI ZANG
  • Affiliation/Institution: The Chinese University of Hong Kong
  • Country: Hong Kong S.A.R.

  • Full Name: IOI CHIT CHEUNG
  • Affiliation/Institution: The Chinese University of Hong Kong
  • Country: Hong Kong S.A.R.

  • Full Name: MINGDE CAO
  • Affiliation/Institution: The Chinese University of Hong Kong
  • Country: Hong Kong S.A.R.

  • Full Name: MICHAEL TIM YUN ONG
  • Affiliation/Institution: The Chinese University of Hong Kong
  • Country: Hong Kong S.A.R.

  • Full Name: PATRICK SHU HANG YUNG
  • Affiliation/Institution: The Chinese University of Hong Kong
  • Country: Hong Kong S.A.R.
Presenter
Xin Yang
Abstract
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Background
    Despite advances in rehabilitation protocols, significant muscle atrophy and strength deficits commonly persist following ACL reconstruction (ACLR). Myokines, including insulin-like growth factor-1 (IGF-1), brain-derived neurotrophic factor (BDNF), and myostatin (MSTN), play key roles in muscle growth, regeneration, and inhibition of myogenesis. However, the relationship between changes in these circulating myokines and functional and morphological recovery after ACLR remains unclear.
Objectives
    This study aims to examine the association between strength recovery and circulating myokine responses following ACLR.
Study design
   This prospective cohort study included 29 patients who underwent ACLR (CREC no:  2021.332). Isokinetic dynamometry assessed quadriceps strength at 4 and 6 months postoperatively. Ultrasound measured the thickness of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles. Magnetic Resonance Imaging (MRI) quantified the volume of the quadriceps and hamstring muscle groups. Serum samples were collected concurrently and quantified IGF-1, BDNF, and MSTN with ELISA. Participants were stratified by postoperative 4-month myokine levels, and ANCOVA was performed for analysis. Statistical analysis also included Spearman correlation analysis.
Results
    At 4 months post-ACLR, serum BDNF levels showed moderate positive correlations with the thickness of the RF (r= 0.413, p= 0.026) and VL (r= 0.379, p= 0.043). Serum MSTN levels correlated moderately with quadriceps muscle volume (r= 0.573, p= 0.001) and with hamstring volume (r= 0.398, p= 0.040). No significant correlations were found for IGF-1. When stratified by a BDNF cutoff of 20 ng/mL, the high-BDNF group (n= 11) showed significantly greater improvement in flexion strength recovery (60°/s: p= 0.024; 180°/s: p= 0.047) between 4 and 6 months compared to the low-BDNF group (n= 18). No significant differences were found when groups were stratified by IGF-1 levels.
Conclusions
    This study demonstrates that circulating myokines, particularly BDNF and MSTN, are differentially associated with morphological and functional recovery after ACLR. The positive correlation of BDNF with early muscle thickness and its predictive value for subsequent strength recovery highlight its potential role in neuromuscular adaptation. MSTN showed a positive, rather than inhibitory, association with muscle volume, possibly reflecting its complex role in tissue remodeling post-injury. These findings suggest that BDNF and MSTN could potentially serve as biomarkers for monitoring rehabilitation progress and identifying patients at risk of suboptimal recovery. Future research should investigate the longitudinal dynamics of these myokines with larger sample size cohort.