Trial Outcomes & Findings for Saphenous Nerve Block vs. Femoral Nerve Block for Total Knee Arthroplasty (NCT NCT01505374)

NCT ID: NCT01505374

Last Updated: 2022-04-14

Results Overview

The primary outcome is the postoperative pain in each leg within the first 24 hours postoperatively. VAS pain scores could range from 0 to 10. Higher values represent a worse outcome.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

60 participants

Primary outcome timeframe

Up to postoperative day 1

Results posted on

2022-04-14

Participant Flow

Recruitment was from the period of 4/16/12-9/4/13 at the Hospital for Special Surgery. Patients were identified on the day of surgery and randomized prior to the start of surgery.

Patients were excluded prior to randomization if they had contraindications to spinal or epidural anesthesia, had chronic opioid use, pre-existing neuropathies in the limbs, allergies to pre-operative medications, contraindication to assigned nerve blocks, allergy to local anesthetic, American Society of Anesthesia 4-5, and non-English speaking.

Participant milestones

Participant milestones
Measure
Study Technique Right Leg, Control Technique Left Leg
Study Technique Left Leg, Control Technique Right Leg
Overall Study
STARTED
30
30
Overall Study
COMPLETED
29
30
Overall Study
NOT COMPLETED
1
0

Reasons for withdrawal

Reasons for withdrawal
Measure
Study Technique Right Leg, Control Technique Left Leg
Study Technique Left Leg, Control Technique Right Leg
Overall Study
Lost to Follow-up
1
0

Baseline Characteristics

Saphenous Nerve Block vs. Femoral Nerve Block for Total Knee Arthroplasty

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
All Study Participants
n=60 Participants
Age, Customized
Age
64.41 years
STANDARD_DEVIATION 7.36 • n=5 Participants
Sex: Female, Male
Female
33 Participants
n=5 Participants
Sex: Female, Male
Male
27 Participants
n=5 Participants
Region of Enrollment
United States
60 participants
n=5 Participants

PRIMARY outcome

Timeframe: Up to postoperative day 1

The primary outcome is the postoperative pain in each leg within the first 24 hours postoperatively. VAS pain scores could range from 0 to 10. Higher values represent a worse outcome.

Outcome measures

Outcome measures
Measure
Study Technique: Saphenous Nerve Block
n=59 Participants
Study Technique: One leg will receive the saphenous nerve block, at the level of the adductor canal. The block will be under ultrasound guidance. The local anesthetic will be 15 ml of 0.5% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Control Technique: Femoral Nerve Block
n=59 Participants
Control Technique: The other leg will receive the femoral nerve block. The block will be under ultrasound guidance. The local anesthetic will be 30 ml of 0.25% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Visual Analogue Scale Pain Score
2.81 units on a scale
Standard Deviation 2.42
2.47 units on a scale
Standard Deviation 2.38

SECONDARY outcome

Timeframe: Up to postoperative day 2

Outcome measures

Outcome measures
Measure
Study Technique: Saphenous Nerve Block
n=59 Participants
Study Technique: One leg will receive the saphenous nerve block, at the level of the adductor canal. The block will be under ultrasound guidance. The local anesthetic will be 15 ml of 0.5% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Control Technique: Femoral Nerve Block
Control Technique: The other leg will receive the femoral nerve block. The block will be under ultrasound guidance. The local anesthetic will be 30 ml of 0.25% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Tracking Total Opioid Usage
133.11 milligrams
Standard Deviation 114.53

SECONDARY outcome

Timeframe: Up to postoperative day 2

This was measured with a dynamometer to gauge strength.

Outcome measures

Outcome measures
Measure
Study Technique: Saphenous Nerve Block
n=59 Participants
Study Technique: One leg will receive the saphenous nerve block, at the level of the adductor canal. The block will be under ultrasound guidance. The local anesthetic will be 15 ml of 0.5% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Control Technique: Femoral Nerve Block
n=59 Participants
Control Technique: The other leg will receive the femoral nerve block. The block will be under ultrasound guidance. The local anesthetic will be 30 ml of 0.25% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Preoperative and Postoperative Thigh Muscle Strength in Both Legs
Baseline
17.06 kilogram-force unit
Standard Deviation 10.65
17.24 kilogram-force unit
Standard Deviation 14.37
Preoperative and Postoperative Thigh Muscle Strength in Both Legs
6-8 h postoperative
2.86 kilogram-force unit
Standard Deviation 3.55
2.45 kilogram-force unit
Standard Deviation 3.31
Preoperative and Postoperative Thigh Muscle Strength in Both Legs
24 h postoperative
5.00 kilogram-force unit
Standard Deviation 3.68
5.08 kilogram-force unit
Standard Deviation 4.06
Preoperative and Postoperative Thigh Muscle Strength in Both Legs
48 postoperative
3.35 kilogram-force unit
Standard Deviation 2.62
3.76 kilogram-force unit
Standard Deviation 3.35

SECONDARY outcome

Timeframe: Up to postoperative day 1

Rated on a 0-10 scale, with a higher score representing greater satisfaction.

Outcome measures

Outcome measures
Measure
Study Technique: Saphenous Nerve Block
n=59 Participants
Study Technique: One leg will receive the saphenous nerve block, at the level of the adductor canal. The block will be under ultrasound guidance. The local anesthetic will be 15 ml of 0.5% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Control Technique: Femoral Nerve Block
n=59 Participants
Control Technique: The other leg will receive the femoral nerve block. The block will be under ultrasound guidance. The local anesthetic will be 30 ml of 0.25% bupivacaine. All study patients, regardless of study arm will receive combined spinal epidural, with 3 ml of 0.5% bupivacaine as the spinal agent. Epidural local anesthetic, if needed, will consist of 2% lidocaine.
Patient Satisfaction With Nerve Blocks
8 units on a scale
Standard Deviation 2.4
8.4 units on a scale
Standard Deviation 2.3

SECONDARY outcome

Timeframe: Up to postoperative day 2

Population: The duration of motor and sensory blockade was not calculated and analyzed, because accurate data regarding block resolution time could not be acquired from patients.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to postoperative day 2

Population: The success of nerve blocks was not collected or analyzed. Instead, muscle strength was collected (data are presented in another table).

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to postoperative day 2

Population: Analysis of postoperative complications was not performed because sufficient data could not be collected regarding the secondary outcome

Outcome measures

Outcome data not reported

Adverse Events

Study Technique: Saphenous Nerve Block

Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths

Control Technique: Femoral Nerve Block

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Study Technique: Saphenous Nerve Block
n=60 participants at risk
Control Technique: Femoral Nerve Block
n=60 participants at risk
General disorders
Epidural failure
1.7%
1/60 • Number of events 1 • The study was monitored for adverse events over the course of 1 year.
0.00%
0/60 • The study was monitored for adverse events over the course of 1 year.

Additional Information

Stavros G. Memtsoudis, MD, PhD

Hospital for Special Surgery

Phone: 212-606-1206

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place