An interventional study of Experimental-Active taVNS and Sham transcutaneous auricular vagus nerve stimulation in Anterior Cruciate Ligament Injuries, Recovery Quality and Auricular Vagus Nerve Stimulation, sponsored by Peking University Third Hospital. Not yet recruiting at 1 site in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by Peking University Third Hospital · Not applicable, Interventional, and Treatment
Background: Arthroscopic anterior cruciate ligament reconstruction (ACLR) is a common orthopedic surgery. Postoperative pain, inflammatory response and opioid-related adverse events impair early recovery quality. Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique with potential analgesic and anti-inflammatory effects.
Participants: A total of 144 eligible participants undergoing ACLR under spinal anesthesia combined with an adductor canal block will be enrolled.
Methods: This prospective, randomized, double-blind, sham-controlled trial will evaluate the effects of perioperative taVNS on early postoperative recovery. Participants will be randomly assigned in a 1:1 ratio to receive active taVNS or sham stimulation. Each participant will receive three 30-minute stimulation sessions, scheduled 30-45 minutes before surgery, 6 ± 1 hours after surgery, and 18 ± 1 hours after surgery. All participants will receive standardized multimodal postoperative analgesia. The primary outcome will be the score on the 15-item Quality of Recovery (QoR-15) questionnaire at 24 hours after surgery. Secondary outcomes will include rescue opioid consumption expressed as oral morphine equivalents, pain scores measured using the Numeric Rating Scale (NRS), functional recovery, and adverse events.
Conclusion: The investigators hypothesize that perioperative taVNS will improve early postoperative recovery quality after ACLR.
523 studies on the registry are indexed under Anterior Cruciate Ligament Injuries; 170 are open to participants now.
This study's planned enrollment of 144 is above the median of 56 across 380 interventional studies indexed under Anterior Cruciate Ligament Injuries.
Browse Anterior Cruciate Ligament Injuries studies →Peking University Third Hospital is the lead sponsor of 752 studies on the registry; 273 are open to participants now.
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Exclusion Criteria:
Participants receive active transcutaneous auricular vagus nerve stimulation (taVNS) on left cymba concha in three 30-minute sessions. All participants in this arm receive standardized spinal anesthesia, adductor canal block, multimodal postoperative analgesia and standardized postoperative rehabilitation protocol.
Device: Experimental-Active taVNS
Participants receive sham taVNS with identical device, electrode position (left cymba concha), timing and screen feedback as experimental group, without active therapeutic current output. All anesthesia, nerve block, analgesia and rehabilitation procedures are identical to the experimental arm.
Device: Sham transcutaneous auricular vagus nerve stimulation
Transcutaneous auricular vagus nerve stimulation (taVNS) delivered via electrodes placed on left cymba concha. Stimulus parameters: 20 Hz frequency, pulse width 250 μs. Current is slowly increased to the subject's threshold of non-painful tingling and then reduced to sub-threshold level. Three 30-minute stimulation sessions are performed: 30-45 minutes pre-operatively, 6±1 hours post-operation, and 18±1 hours post-operation. All participants receive standardized spinal anesthesia, adductor canal block, multimodal postoperative analgesia and postoperative rehabilitation protocol.
Using the same equipment, the same position of the left cymba concha, and the same 30-minute timing. Each time, the current is slowly increased within 30 seconds at the beginning until the first clear but non-painful slight tingling sensation is achieved; then it is gradually reduced to 0 mA within 15 to 30 seconds, and remains at 0 mA for the rest of the time, while the screen, timing, and alert sounds continue to operate. Study participants in both groups are informed that stimulation sensation may weaken or disappear with adaptation and that sensation intensity cannot be used to determine group assignment. Anesthesia, block, postoperative analgesia, and rehabilitation training are all exactly the same as the experimental group.
Quality of Recovery-15 (QoR-15) score
Validated 15-item patient-reported questionnaire assessing postoperative recovery quality. Total score ranges from 0-150; higher score indicates better postoperative recovery quality.
Time frame: 24 hours after surgery
Cumulative oral morphine equivalent (OME) consumption of rescue analgesics
Total cumulative rescue opioid analgesic consumption converted to oral morphine equivalent (OME) over the observation period.
Time frame: 0 to 24 hours after surgery
Time to first rescue analgesic requirement
Time interval from the end of surgery to the first administration of rescue analgesic medication for pain.
Time frame: Within 24 hours after surgery
Resting NRS pain score (0-10; higher=worse pain)
Numeric Rating Scale (NRS) for pain; score range 0-10, 0 = no pain, 10 = worst imaginable pain; assessed at rest.
Time frame: 0, 4, 8, 12, and 24 hours after surgery
Activity-evoked NRS pain score (passive knee flexion 45°)
Numeric Rating Scale (NRS) for pain (0-10; higher score = worse pain). Pain elicited by standardized passive knee flexion to 45 degrees. Not evaluable if regional block has not resolved.
Time frame: 4, 8, 12, and 24 hours after surgery
Maximal NRS pain score
The highest observed Numeric Rating Scale pain score within the observation window (resting pain). Score range 0-10; higher score represents worse pain.
Time frame: 0 to 24 hours after surgery
Time to first standardized out-of-bed mobilization
Time interval from the end of surgery until completion of the first standardized out-of-bed mobilization (sitting, standing and walking ≥3 m under assistance).
Time frame: From the end of surgery until hospital discharge, approximately 1 day after surgery
Post-operative night sleep quality score (0-10; higher=better sleep)
Patient-reported sleep quality score, range 0-10; 0 = extremely poor sleep, 10 = excellent sleep. Assessed for the first night after surgery.
Time frame: During the first night after surgery
Incidence of opioid-related adverse events (PONV, pruritus, urinary retention, over-sedation, respiratory depression)
Number / proportion of participants experiencing at least one opioid-related adverse event including postoperative nausea and vomiting (PONV), pruritus, urinary retention, over-sedation, respiratory depression.
Time frame: 0 to 24 hours after surgery
Incidence of intervention-related adverse events (ear pain, erythema, dizziness, palpitation)
Number / proportion of participants experiencing adverse events related to taVNS intervention: ear pain, local skin erythema, dizziness, palpitation.
Time frame: During stimulation sessions and the first 24 hours after surgery
Patient global satisfaction score (0-10; higher=higher satisfaction)
Patient-reported global satisfaction score, range 0-10; higher score indicates higher overall satisfaction with peri-operative care.
Time frame: 24 hours after surgery
Plan to share: No
Start is estimated for Oct 2026; primary completion for Jun 2027, 7 months later.
Of 241 non-industry interventional studies with no phase under Anterior Cruciate Ligament Injuries, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 14 and three quarters within 70. This study's planned 7 months is below that.
Counting every sponsor, half of 248 studies reached it within 30 months; a quarter within 14 and three quarters within 70.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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