Postoperative Pain Management in Total Knee Arthroplasty
Conditions
Keywords
Anterior Femoral Cutaneous Nerve Block, Total Knee Arthroplasty
Brief summary
This randomized controlled trial evaluates the additive effect of Supra-Sartorial Subcutaneous Infiltration (SSSI) when performed in combination with intermittent adductor canal block (iACB) and posterior capsule local infiltration analgesia (PC-LIA) for pain management after total knee arthroplasty (TKA). SSSI, an easy-to-perform tentative proxy block to targeted anterior femoral cutaneous nerve (AFCN) block, is tested in 90 adults (45-90 years) randomized into two arms: active SSSI versus sham SSSI. Primary outcome is pain scores at rest and during movement on postoperative day 0; secondary outcomes include daily pain trajectory at rest and during movement, functional recovery scores, rescue analgesic doses over days 0-3, and quality of recovery assessment on day 4.
Detailed description
This prospective, double-blinded, sham-controlled randomized controlled trial investigates the additive analgesic effect of Supra-Sartorial Subcutaneous Infiltration (SSSI) when combined with intermittent adductor canal block (iACB) and posterior capsule local infiltration analgesia (PC-LIA) following total knee arthroplasty (TKA). The SSSI technique was developed as a simplified, practical alternative to the technically demanding targeted anterior femoral cutaneous nerve (AFCN) block. Drawing on preliminary data where SSSI provided clinically meaningful analgesia in approximately 58% of patients when paired with PC-LIA, this trial evaluates the role of SSSI in enhancing motor-sparing analgesia within a multimodal framework. The study will enroll 90 adults between the ages of 45 and 90 undergoing unilateral primary TKA. Participants will be randomized 1:1 into two groups of 45, with stratification based on gender and baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. All active interventions utilize 0.3% ropivacaine, while the control arm utilizes saline shams for the SSSI component. The SSSI and iACB catheterizations are performed by anesthesiologists in the post-anesthesia care unit, whereas the PC-LIA is administered intraoperatively by the surgical team. Patients in the active group receive active SSSI, active iACB, and active PC-LIA, while those in the sham group receive a saline SSSI alongside active iACB and active PC-LIA. The primary outcome is defined as Visual Analog Scale (VAS) pain scores at rest and during movement at 9:00 PM on postoperative day 0. Secondary outcomes include daily VAS pain scores at rest and during functional assessments such as continuous passive motion (CPM) and the timed up-and-go (TUG) test through postoperative day 1-4. Additionally, the trial monitors the maximal allowable degree of CPM, TUG test performance, cumulative rescue analgesic doses over the first 4 postoperative days, and Quality of Recovery-15 (QoR-15) scores on postoperative day 4. With approximately 96% power to detect a 2-point difference in pain scores, the trial aims to determine if SSSI significantly improves postoperative analgesia without compromising motor function.
Interventions
PROCEDURESupra-Sartorial Subcutaneous Infiltration (SSSI)
20 mL Ropivacaine or saline infiltrated subcutaneously from lateral to medial, superficial to vastus medialis and sartorius muscle, at femoral triangle apex using inject-as-you-advance technique, avoiding hyperechoic nerves.
PROCEDUREintermittent adductor canal block (iACB)
A single-shot adductor canal block is first performed post-operatively with 20 mL 0.3% Ropivacaine at the level of femoral triangle apex before inserting a catheter into the canal. The following doses (20 mL each time) start at 9:00 PM on the day of surgery and are intermittently given every 12 hours until day 4.
PROCEDUREposterior capsule local infiltration analgesia (PC-LIA)
PC-LIA consists of two 10 mL injections of 0.3% ropivacaine delivered intraoperatively to the posteromedial and posterolateral aspects of the posterior capsule before cementation. The target injection plane is the potential space between the posterior capsule and the popliteal artery.
Sponsors
Taipei Medical University WanFang Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)
Eligibility
Sex/Gender
ALL
Age
45 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
* Adults aged 45-90 undergoing unilateral primary TKA for osteoarthritis. * American Society of Anesthesiologists (ASA) physical status I-III. * Able to provide informed consent and use NRS pain scales. * Surgery scheduled to start before noon to standardize spinal anesthesia recovery.
Exclusion criteria
* Bilateral or revision TKA. * Contraindications to regional anesthesia (e.g., coagulopathy, infection at injection site). * Chronic opioid use (\>30 mg morphine equivalents/day) or preoperative NRS \>4. * Pre-existing neurological deficits in lower extremities or AFCN-related neuropathy. * Allergy to ropivacaine. * Pregnancy, breastfeeding, or cognitive impairment affecting assessments.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pain: VAS at rest and during movement on postoperative day 0 | at 9 PM on postoperative day 0 | VAS pain scores at rest and during continuous passive motion will be taken on postoperative day 0 at 9 PM. Higher VAS pain scores indicate worse pain levels. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pain: VAS at rest and during movement from postoperative day 1-4 | From postoperative day 1 at 6 AM to postoperative day 4 at 6 AM. | VAS pain scores will be taken at rest and during CPM and TUG test on postoperative day 1 (6 AM, 6 PM), POD 2 (6 AM, 6 PM), POD 3 (6 AM, 6 PM), and POD 4 (6 AM). Higher VAS pain scores indicate worse pain levels. |
| Rescue ACB doses (0.3% ropivacaine, mg) | From the time discharging from post-anesthesia care unit to postoperative day 4 at 6 AM | Rescue ACB will be administered via catheter as needed outside of the scheduled doses (from postoperative day 0 at 9 PM to postoperative day 4 at 6 AM, q12 hours). |
| Additional morphine doses (mg) | From the time discharging from post-anesthesia care unit to postoperative day 4 at 6 AM | Intravenous morphine as bolus or patient-controlled analgesia may be administered as needed if regional anesthesia fails to provide adequate analgesia (VAS pain \<4). |
| Functional: TUG test | From postoperative day 1 at 6 AM to postoperative day 4 at 6 AM. | Daily TUG test will be performed from postoperative day 1 at 6 AM to postoperative day 4 at 6 AM, q24 hours. TUG test is measuted in seconds, with higher values indicating poorer functional recovery. |
| Functional: CPM maximal allowable angle | From postoperative day 0 at 9 PM to day 3 at 6 PM. | CPM maximal allowable angle will be increased q24 hours according to patient's tolerance from day 0 at 9 PM to day 3 at 6 PM. CPM angle is measured in degree, with higher values indicating better postoperative recovery. |
| Quality of Recovery | At postoperative day 4 at 6 AM. | Quality of Recovery-15 (QoE-15) scores will be taken on postoperative day 4 at 6 AM. Value range 0-150, with higher scores indicating better recovery. |
Countries
Taiwan
Contacts
CONTACTShang-Ru Yeoh, MD, MSc
Outcome results
None listed