Pain Management
Conditions
Keywords
pain management for total knee arthroplasty
Brief summary
The purpose of the study is to determine the effect of a single injection adductor canal block (ACB) on pain scores within 24 hours post total knee arthroplasty (TKA).
Detailed description
Total knee arthroplasty (TKA), also known as total knee replacement, has been associated with a significant pain burden in the postoperative period. Methods to manage pain associated with this operation have in the past included injecting pain medication into the epidural space of the spinal cord, around a peripheral nerve, around the space surrounding the joint, or a combination of pain management techniques. In recent years, the femoral nerve block (injection of pain medication around the peripheral nerve, specifically the femoral nerve) has been proposed as an effective way to manage pain while sparing many of the undesirable side effects of narcotic pain medications. Traditional techniques of the femoral nerve block involve the injection of pain medication around the peripheral nerve at the level of the groin area. A nerve block at this point in the path of the femoral nerve affects all of the musculature of the front part of the thigh as well as the nerves responsible for sensation to the majority of the knee joint. The femoral nerve block performed at the level of the groin provides an excellent level of pain relief at the knee joint, but is also associated with weakness of the quadriceps muscle. The resultant quadriceps weakness can both slow the physical therapy process and be a risk factor for post-operative falls. Participation in physical therapy is a critical component of the rehabilitation process and is started as soon as tolerated by the patient. The ideal pain management technique would provide the same degree of pain relief as the femoral nerve block while preserving the strength in the front part of the thigh muscles. One suggested technique to achieve both of these goals is the injection of a large volume dilute local pain medication mixture around the joint during surgery. This has been used as a substitute to provide pain relief around the joint while maintaining strength in the quadriceps muscle and the ability to participate in physical therapy. This technique however, does not last long since the medication disperses away from the joint space. A variation of the femoral nerve block in the lower thigh, within a space called the adductor canal, has been demonstrated to provide equivalent amounts of pain relief as a proximal femoral nerve block along with preservation of motor function to the quadriceps muscle. What is not as well-established is whether the combination of injecting pain medication directly around the joint space in the knee along with a single injection of pain medication in the adductor canal in the lower thigh can improve pain scores and extend the duration of pain relief provided compared to only an injection around the joint space.
Interventions
OTHERACB Control - 20 ml saline injection for ACB
Adductor Canal Block Control (20 ml saline injection)
DRUGACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block
Adductor Canal Block Study (20 ml 0.5% Ropivacaine)
DRUGLocal infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline
100 mLs of a solution containing: Ropivacaine 2 mg/mL (49.25 mL) + Epinephrine 1 mg/mL (0.5 mL) + Ketorolac 30mg/mL (1mL) + Clonidine 100 mcg/mL (0.8 mL) + 0.9% Normal saline (48.45 mL)
Sponsors
University of California, Irvine
Study design
Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Males and Females age 18+ years old having total knee arthroplasty (TKA) at UCI Medical Center * American Society of Anesthesiologists physical status I to III
Exclusion criteria
* Allergy to local anesthetics * Pregnancy * Nursing Mothers * Children \<18 years of age * Renal impairment (GFR\<60 mL/min/1.73m2) * Hepatic Impairment (active hepatitis, elevated AST or ALT, jaundice) * Opioid tolerant patients (defined as greater than 30 mg Morphine equivalent consumed daily) * Patients that are diabetic with peripheral neuropathy * BMI greater than 40
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pain Score | within 24 hours postoperative | The primary outcome variable of interest is the median maximum pain score within 24 hours postoperative. Pain scores were rated on a scale from 0 - 10, with 0 being no discomfort/pain and 10 being worst imaginable pain. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Opioid Use | within 24 hours postoperative | 24 Hour post-surgical opioid use |
| Ambulation Distance | First 24 hours post-operative | Total distance ambulated during physical therapy during first 24 hours |
Other
| Measure | Time frame | Description |
|---|---|---|
| Baseline Anxiety | pre-operative day of surgery | Self-reported subject anxiety prior to surgery |
| Baseline Pain Score | Preoperatively day of surgery | Baseline pain preoperatively |
| NRS Pain Rating | Preop, PACU, and 4,8, 12, and 24 hours post-operatively. | A modified pain score similar to VAS but rated from 0-10 |
Countries
United States
Participant flow
Recruitment details
Subjects were recruited from the main operating room from January 2015 through December of 2019. Recruitment was prolonged due to PI changes secondary to personnel leaving the university.
Participants by arm
| Arm | Count |
|---|---|
| ACB Control + Local Infiltration ACB Control - 20 ml saline injection for ACB + Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline
ACB Control - 20 ml saline injection for ACB: Adductor Canal Block Control (20 ml saline injection)
Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline: 100 mLs of a solution containing:
Ropivacaine 2 mg/mL (49.25 mL) + Epinephrine 1 mg/mL (0.5 mL) + Ketorolac 30mg/mL (1mL) + Clonidine 100 mcg/mL (0.8 mL) + 0.9% Normal saline (48.45 mL) | 18 |
| ACB Study + Local Infiltration ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block + Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline
ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block: Adductor Canal Block Study (20 ml 0.5% Ropivacaine)
Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline: 100 mLs of a solution containing:
Ropivacaine 2 mg/mL (49.25 mL) + Epinephrine 1 mg/mL (0.5 mL) + Ketorolac 30mg/mL (1mL) + Clonidine 100 mcg/mL (0.8 mL) + 0.9% Normal saline (48.45 mL) | 17 |
| ACB Study Only ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block
ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block: Adductor Canal Block Study (20 ml 0.5% Ropivacaine) | 20 |
| Total | 55 |
Baseline characteristics
| Characteristic | ACB Control + Local Infiltration | ACB Study + Local Infiltration | ACB Study Only | Total |
|---|---|---|---|---|
| Age, Continuous | 65 years | 68 years | 67 years | 67 years |
| Height (cm) | 169 centimeters | 167 centimeters | 169 centimeters | 169 centimeters |
| Race and Ethnicity Not Collected | — | — | — | 0 Participants |
| Region of Enrollment United States | 18 Participants | 17 Participants | 20 Participants | 55 Participants |
| Sex: Female, Male Female | 11 Participants | 9 Participants | 9 Participants | 29 Participants |
| Sex: Female, Male Male | 7 Participants | 8 Participants | 11 Participants | 26 Participants |
| Weight (lbs) | 198 pounds | 207 pounds | 181 pounds | 188 pounds |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 18 | 0 / 17 | 0 / 20 |
| other Total, other adverse events | 0 / 18 | 0 / 17 | 0 / 20 |
| serious Total, serious adverse events | 0 / 18 | 0 / 17 | 0 / 20 |
Outcome results
Primary
Pain Score
The primary outcome variable of interest is the median maximum pain score within 24 hours postoperative. Pain scores were rated on a scale from 0 - 10, with 0 being no discomfort/pain and 10 being worst imaginable pain.
Time frame: within 24 hours postoperative
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Joint Infiltration Only | Pain Score | 5 units on a scale |
| ACB + Joint Infiltration | Pain Score | 4.5 units on a scale |
| ACB Only | Pain Score | 4 units on a scale |
p-value: 0.668Kruskal-Wallis
Secondary
Ambulation Distance
Total distance ambulated during physical therapy during first 24 hours
Time frame: First 24 hours post-operative
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Joint Infiltration Only | Ambulation Distance | 140 feet |
| ACB + Joint Infiltration | Ambulation Distance | 350 feet |
| ACB Only | Ambulation Distance | 95 feet |
p-value: 0.013Kruskal-Wallis
Secondary
Opioid Use
24 Hour post-surgical opioid use
Time frame: within 24 hours postoperative
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Joint Infiltration Only | Opioid Use | 38 Daily mg morphine equivalents |
| ACB + Joint Infiltration | Opioid Use | 0 Daily mg morphine equivalents |
| ACB Only | Opioid Use | 26 Daily mg morphine equivalents |
p-value: 0.006Kruskal-Wallis
Other Pre-specified
Baseline Anxiety
Self-reported subject anxiety prior to surgery
Time frame: pre-operative day of surgery
Population: Data was incompletely collected across the study so no analysis performed
Other Pre-specified
Baseline Pain Score
Baseline pain preoperatively
Time frame: Preoperatively day of surgery
Population: Study data was incompletely collected across the study period so no analysis was performed
Other Pre-specified
NRS Pain Rating
A modified pain score similar to VAS but rated from 0-10
Time frame: Preop, PACU, and 4,8, 12, and 24 hours post-operatively.
Population: NRS scores were not collected during the study, so no analysis is performed.