Clinical and laboratory predictors of postoperative pain after arthroscopic anterior cruciate ligament reconstruction in patients with obesity.

Abstract

Background. Anterior Cruciate Ligament (ACL) injury is one of the leading causes of knee instability and reduced functional activity. The results of arthroscopic ACL reconstruction depend largely on the patient's metabolic status. Aim. To determine the clinical and laboratory characteristics of patients with isolated ACL injury and obesity before arthroscopic reconstruction and to identify factors associated with increased pain intensity at 2 months after surgery in this patient population. Materials and Methods. This single-center prospective controlled non-randomized study included 90 consecutively enrolled patients with isolated ACL injury of the knee joint who were treated in the Department of Traumatology of the Regional Clinical Hospital, a Municipal Nonprofit Enterprise of the Kharkiv Regional Council, between 2022 and 2024. The groups were formed according to BMI: the main group consisted of 38 patients with obesity (BMI ≥30 kg/m²), and the control group included 52 patients without obesity (Body Mass Index (BMI) <30 kg/m²). The following parameters were assessed: Total Cholesterol (TC), Low-Density Lipoproteins (LDL), Very-Low-Density Lipoproteins (VLDL), High-Density Lipoproteins (HDL), TriGlycerides (TG), beta-LipoProteins (β-LP), and the Atherogenic Index (AI). Pain intensity at 2 months after arthroscopic ACL reconstruction was assessed using the Visual Analog Scale (VAS), and associated clinical and laboratory factors were analyzed. Statistical analysis was performed using nonparametric methods and multiple linear regression. Research Ethics. All patients provided informed consent for participation in the study. The study was conducted in accordance with the Nuremberg Code and the World Medical Association Declaration of Helsinki (1964–2024). The study protocol was approved by the Bioethics Committee of Kharkiv National Medical University (Protocol No 4 of 01.04.2026). Results. The obesity group had significantly higher levels of TC, LDL, VLDL, TG, β-LP, and AI, as well as lower HDL levels (p≤0.001). Obesity (β=0.320; p=0.004) and a higher preoperative VAS score (β=0.237; p=0.001) were independently associated with greater pain intensity at 2 months after ACL reconstruction. Conclusions. The most clinically significant independent predictors of persistent pain at 2 months after arthroscopic ACL reconstruction were obesity and a higher preoperative pain level.