Analgesic Efficacy of Preemptive Stepwise Infiltration Anesthesia for Perioperative Analgesia After TKA

Postoperative morphine consumption within the first 24 hours includes both routine analgesia and rescue analgesia, which will be converted to oral morphine equivalents (OMEs)

VAS scores are the most commonly used indicator for assessing the intensity of patient pain (15). The scale ranges from "0" to "10", where "0" indicates no pain and "10" represents the most severe pain that is unbearable. Patients will rate their pain based on subjective perceptions. In this trial, VAS scores will be recorded once before TKA. The VAS scores will be assessed separately for the resting and flexion states. If the patient's hospitalization period is shorter than 72 hours, the VAS score at discharge will be recorded instead of that at 72 hours. Studies have shown that some patients still experience joint pain six months after TKA. The VAS scores of patients at 6 months after TKA will be evaluated. A VAS score of 4 or above is defined as "chronic persistent pain after TKA." The results will be used to evaluate whether PSIA can reduce pain after TKA.

Rescue analgesia will be initiated when the patient reports local knee joint pain on the operative side with a VAS score > 4. The specific steps will be implemented as described previously. The time to rescue analgesia will be recorded.

It will be converted to total morphine equivalents and will include both the postoperative routine pain management regimen and rescue analgesia.

The Hospital for Special Surgery Knee Score (HSS) is a patient-reported questionnaire specific to the knee joint, with a total score of 100 points. It comprises six scoring components: pain (30 points), function (22 points), range of motion (18 points), muscle strength (10 points), knee deformity (10 points) and stability (10 points). Additional points are deducted for the use of assistive devices, extension lag and varus deformity: up to 3 points for assistive device use, up to 5 points for extension lag and 1 point deducted for every 5 degrees of varus deformity. The scores are classified as follows: ≥ 85 as "Excellent", 70-84 as "Good", 60-69 as "Fair", and < 60 as "Poor". The HSS score is widely praised for its perceived ease of use and quick recording and has been shown to be an effective and reliable measure for assessing the efficacy of TKA.

The range of motion (ROM) will be measured with a protractor thrice daily at 6-hour intervals, and the best value on each day will be used in the analysis. The range of motion (ROM) is from 0 to 180 degrees. The larger the angle, the more satisfactory the recovery of joint function.

Intraoperative bleeding will be recorded directly by anesthesiologists (mL).

Intraoperative bleeding will be estimated by subtracting the preoperative hemoglobin level from the hemoglobin level measured 24 hours postoperatively.

A complete blood count (CBC) can reflect the patient's postoperative inflammatory status. It measures various components of the blood, including white blood cells, red blood cells, and platelets, which can indicate the presence of inflammation or infection. An elevated white blood cell count, for example, is often associated with an inflammatory response.

C-reactive protein (CRP) can reflect the patient's postoperative inflammatory status.

Erythrocyte sedimentation rate (ESR) can reflect the patient's postoperative inflammatory status.

Interleukin-6 (IL-6) can reflect the patient's postoperative inflammatory status.

Total bilirubin will be used to evaluate the impacts of surgical trauma and medications on patients.

Derect bilirubin will be used to evaluate the impacts of surgical trauma and medications on patients.

Aspartate aminotransferase will be used to evaluate the impacts of surgical trauma and medications on patients.

Alanine aminotransferase will be used to evaluate the impacts of surgical trauma and medications on patients.

Creatinine will be used to evaluate the impacts of surgical trauma and medications on patients.

Age in years will be obtained from the electronic medical records system.

Sex (male or female) will be obtained from the electronic medical records system.

Operative site (left or right) will be obtained from the electronic medical records system.

Weight (kg) and height (m) will be combined to report BMI in kg/m^2, which will be obtained from the electronic medical records system. This information will be collected by the same evaluator and used to calculate the age-corrected Charlson Comorbidity Index (aCCI), baseline ROM, HSS score and VAS score for these patients.

Inpatient data will include the operative time and time to discharge. These inpatient data will be sourced from the electronic medical records system and used to evaluate the impacts of PSIA and PLIA on the surgical process and postoperative recovery.

Operative time will be sourced from the electronic medical records system and used to evaluate the impacts of PSIA and PLIA on the surgical process and postoperative recovery.

Time to discharge will be sourced from the electronic medical records system and used to evaluate the impacts of PSIA and PLIA on the surgical process and postoperative recovery.

Adverse events (AEs) are adverse medical events that occur in clinical trial subjects after receiving treatment. In this study, total AEs will be mainly categorized into local AEs and systemic AEs. Local AEs include but are not limited to prolonged wound drainage (wound drainage persists on postoperative day 3, and the drainage area of the wound dressing is greater than 2×2 cm , poor wound healing and prosthetic joint infection. Systemic AEs include but are not limited to deep vein thrombosis events, systemic infection and serious adverse events such as pulmonary embolism and death.

We will use a Likert scale to evaluate participants satisfaction with each treatment phase at each assessment. This scale consists of 5 levels (very dissatisfied, dissatisfied, neutral, satisfied and very satisfied) from 1 to 5. After the final follow-up, the total score on the Likert scale for each participant will represent their overall satisfaction to date. The larger the score, the more satisfactory with the participants.