Is it the anesthetic or the experience? Rethinking postoperative anxiety after ACL reconstruction

We read with considerable interest the randomized clinical trial by Huang et al[1] comparing general anesthesia (GA) with regional anesthesia (RA) for arthroscopic ACL reconstruction. The finding that GA was associated with lower postoperative anxiety despite higher cortisol levels raises important questions regarding the dissociation between psychological and neuroendocrine stress responses. While the study offers valuable insights, several issues deserve further clarification. First, the absence of intraoperative sedation in the RA group represents a potentially influential experiential bias. Regional anesthesia was performed without sedation, meaning patients remained fully conscious during surgery. In current practice, however, knee procedures under neuraxial or peripheral blocks are frequently accompanied by light sedation to attenuate distress from environmental stimuli and tourniquet-related discomfort[2]. Psychological exposure to operative sounds, limb manipulation, or perceived loss of control may independently heighten postoperative anxiety through perioperative emotional imprinting. Prior research has shown that intraoperative awareness and anesthesia-related fear can shape postoperative psychological outcomes independently of nociceptive signaling[3,4]. Therefore, the reported anxiety difference may reflect differences in intraoperative experience rather than intrinsic pharmacologic effects of GA versus RA. Incorporating a sedated-RA comparator or formally measuring intraoperative perception would strengthen causal interpretation. Second, the type of peripheral nerve block used in both groups may limit the generalizability of the findings to contemporary practice. Femoral nerve block (FNB) was employed universally; however, adductor canal block (ACB) has increasingly replaced FNB in outpatient ACL reconstruction protocols due to better preservation of quadriceps strength and earlier mobilization[5]. FNB is associated with transient motor weakness and delayed ambulation, which may influence early functional confidence and patient perception of independence. Reduced mobility during the immediate postoperative period could plausibly contribute to heightened vulnerability to anxiety[6]. As enhanced recovery and ambulatory pathways now prioritize early rehabilitation, replication of these comparisons within an ACB-based protocol would improve external validity and align the results with modern perioperative standards. Third, the analytic approach to psychological assessment may constrain interpretation. Anxiety was analyzed dichotomously using a HADS-A cutoff, which may obscure nuanced perioperative trajectories. Anxiety is inherently dynamic and may be better represented as a continuous or longitudinal construct. Furthermore, HADS emphasizes current symptom burden rather than dispositional traits. Extensive literature demonstrates that baseline trait anxiety, catastrophizing, and psychological distress are strong determinants of postoperative emotional outcomes[7,8]. Without deeper psychological phenotyping, it remains unclear whether anesthetic technique interacts with preexisting vulnerability profiles. Finally, focusing exclusively on salivary cortisol may provide an incomplete mechanistic explanation. Although mediation analysis did not implicate cortisol as a causal pathway, perioperative stress regulation involves interconnected autonomic and inflammatory systems beyond the HPA axis. Cytokines and sympathetic markers have been shown to correlate with postoperative mood alterations more consistently than cortisol alone[9]. A broader biomarker framework incorporating inflammatory and autonomic parameters might better account for the observed divergence between physiological and psychological stress indices. In summary, this trial contributes meaningfully to the ongoing discussion regarding individualized anesthetic selection. Future investigations that control intraoperative experiential factors, employ contemporary regional techniques, incorporate multidimensional psychological assessment, and expand biomarker profiling will help clarify the true relationship between anesthetic modality and postoperative emotional recovery. Such refinements are essential for translating these findings into precision-based perioperative care.