Randomized Controlled Trial Evaluating Postoperative Analgesia and Muscle Strength Between Single Versus Continuous Adductor Canal Block for Ambulatory ACL Reconstruction.
Phase: NA
Conditions: Rupture of Anterior Cruciate Ligament, Tear of Anterior Cruciate Ligament
Sponsor: Vanderbilt University Medical Center

Randomized controlled trial evaluating postoperative analgesia and muscle 
strength between single versus continuous adductor canal block for 
ambulatory ACL reconstruction. 
 
Version Date: 08/23/2017 
 
 NCT02584452 
 
 
Christopher M. Sobey, M.D. 
Assistant Professor 
Vanderbilt University Medical Center 
Department of Ambulatory Anesthesiology, Division of Pain Medicine 
1301 Medical Center Drive, 4648 TVC 
Nashville, TN  37232-5614 
 
Daltry Dott, M.D. 
Chief Resident 
Vanderbilt University Medical Center 
Department of Anesthesiology 
2301 Vanderbilt University Hospital 
Nashville, TN 37232-7237 
 
Lisa Jaeger, M.D. 
Assistant Professor 
Vanderbilt University Medical Center 
Department of Ambulatory Anesthesiology 
1301 Medical Center Drive, 4648 TVC 
Nashville, TN  37232-5614 
 
Matthew S. Shotwell, Ph.D. 
Assistant Professor 
Vanderbilt University School of Medicine 
Department of Biostatistics 
2525 West End, Ste. 11000 
Nashville, TN 37203 
 
Scott T. Arthur, M.D. 
Assistant Professor 
Department of Orthopedic Surgery, Vanderbilt Bone and Joint 
206 Bedford Way 
Franklin, TN 37204 
 
Katherine H. Dobie, M.D. 
Assistant Professor 
Vanderbilt University Medical Center 
Department of Anesthesiology, Chief of Ambulatory Anesthesiology  
1301 Medical Center Drive, 4648 TVC 
Nashville, TN  37232-5614 
 

Confidential 
 
 
Table of Contents: 
 
1. Background 
2. Rationale and Specific Aims 
3. Inclusion Criteria 
4. Exclusion Criteria 
5. Enrollment 
6. Study Method 
7. Reporting of Adverse Events or Unanticipated Problems involving Risk to 
Participants or Others 
8. Statistical Considerations 
9. Privacy/Confidentiality Issues 
10. Follow-up and Record Retention 
 
 
 
1. 
Background 
 
Adequate analgesia with maintained functionality is crucial to recovery for patients 
undergoing outpatient anterior cruciate ligament reconstruction.  Perioperative peripheral 
nerve blocks have been utilized in these procedures to maximize postoperative pain, 
minimize side effects from IV analgesics, and facilitate discharge from PACU. The gold 
standard of peripheral nerve blocks for ACL reconstruction has been the femoral nerve 
block1; however, this block has shown to have deleterious side effects such as 
quadriceps weakness, which has been associated with increased risk of falls and 
prolonged recovery postoperatively2-4, 15. Previous studies have focused on sparing the 
motor function of the quadriceps by performing adductor canal block and targeting the 
saphenous nerve, which is a predominantly a sensory nerve5. Studies comparing 
efficacy of femoral nerve blocks compared to adductor canal blocks in total knee 
arthroplasty have shown equal analgesic action with significant sparing of quadriceps 
strength in the adductor canal group6-9.  Utilization of adductor canal blocks for ACL 
reconstruction have yielded varying results in terms of significant postoperative 
analgesia over non-regional based postoperative pain control10-12. However, 
postoperative pain control seems to be equivalent in femoral versus adductor canal 
blocks in ACL reconstruction13. Despite the apparent multifaceted benefit in 
differentiating blockade sites and duration of nerve blockade, the efficacy of continuous 
adductor canal blockade utilized specifically in ACL reconstruction has not been 
extensively studied. Studies comparing single bolus femoral nerve blocks to continuous 
adductor canal catheters are ongoing. The efficacy of continuous adductor canal 
blockade utilized specifically in ACL reconstruction compared to single bolus adductor 
canal blockade has yet to be determined. 
 
 
 
 

2. 
Rationale and Specific Aims 
 
We will conduct a randomized controlled trial evaluating the efficacy of two different 
regional techniques in patients undergoing ACL reconstruction. The primary goal will be 
to determine the differences in postoperative pain on POD 2 when comparing 
preoperative femoral nerve block with mepivacaine plus postoperative continuous 
adductor canal nerve catheter with bupivacaine compared to preoperative femoral nerve 
block with mepivacaine plus postoperative saphenous nerve block with ropivacaine and 
dexamethasone. Primary outcome will be pain scores at 48hrs after PACU discharge. 
Secondary outcomes will include pain scores on POD 0, 1 & 3, opioid utilization on POD 
0, 1, 2 & 3, and quadriceps strength on operative leg at rehab session on POD 1.  
 
Hypothesis 
The use of the adductor canal continuous nerve catheter will result in lower subjective pain 
scores on postoperative day 2 and improved quadriceps strength on postoperative day 1.  
 
 
Primary Aim 
1. Determine the subjective postoperative pain scores at POD 2 of preoperative 
femoral nerve block plus postoperative continuous adductor canal nerve catheter 
compared to preoperative femoral nerve block plus postoperative saphenous 
nerve block at 48 hours after discharge from PACU.  
 
2. Determine the quadriceps strength of on POD 1 of preoperative femoral nerve 
block plus postoperative continuous adductor canal nerve catheter compared to 
preoperative femoral nerve block plus postoperative saphenous nerve block at 
48 hours after discharge from PACU straight leg raise and knee extension tests. 
 
 
Exploratory Aims 
1. Determine the subjective postoperative pain scores on POD 1, 2 and 3 of 
patients receiving (1) preoperative femoral nerve block plus postoperative 
continuous adductor canal nerve catheter compared to (2) preoperative femoral 
nerve block plus postoperative saphenous nerve block.  
2. Determine the total postoperative opioid consumption on POD 1, 2 and 3 of 
patients receiving (1) preoperative femoral nerve block plus postoperative 
continuous adductor canal nerve catheter compared to (2) preoperative femoral 
nerve block plus postoperative saphenous nerve block.  
3. Determine physical therapy participation with a validated assessment tool on 
POD 1. 
4. Determine operative leg strength and pain at 6 weeks post-op.   
 
 
3. 
Inclusion Criteria 
A.  Age 14 and older 
B. Patients who are scheduled to undergo an ACL reconstruction with 
patella or allograft 
C.  Patient does not have a contraindication to receiving regional anesthesia 
 
 

4. 
Exclusion Criteria 
A. Allergy to local anesthetics, dexamethasone, or adhesive tape 
B. Patients undergoing hamstring graft for ACL 
C. Preexisting infection at site of needle insertion 
D. Immunocompromised patients 
E. Preexisting sensory or motor deficit in operative extremity 
F. Patient on chronic opioid treatment.  
G. Patient having a revision of previous ACL reconstruction. 
 
 
H. Pregnancy and lactating women 
 
5. 
Enrollment 
 
We will enroll 100 patients undergoing ACL reconstruction with patella or allograft who 
meet the inclusion criteria stated above. 
 
 
6. 
Study Method 
 
Patients undergoing ACL reconstruction at Vanderbilt Bone and Joint Surgery Center 
by Dr. Scott Arthur will be identified at surgical scheduling and conveyed to 
anesthesia team for inclusion into study. The assigned in-room providers will be 
educated on the protocol and randomization process.  
 
After written informed consent is obtained by either the patient or the designated 
surrogate decision maker, patients will be randomized to 2 groups: (1) continuous 
adductor canal nerve catheter or (2) long-acting single bolus adductor canal nerve 
block.  
 
Following random selection via random envelope selection patients will receive the 
following procedures. Both groups will receive ultrasound guided femoral nerve block 
with 20cc of 2% mepivacaine <20 minutes prior to in room time.  
 
Intraoperative patients will undergo initiation of general anesthesia under the care of 
the attending anesthesiologist assigned to the patient. Induction will include a 
propofol bolus and placement of laryngeal mask airway. Intraoperative opioid should 
be limited to no more than 150mcg of fentanyl. Upon completion of wound closure, 
appropriate dressing placement, emergence from anesthesia and removal of LMA, 
patients to be taken to PACU. Once adequately awake and alert, Group 1 patients  1 
will receive ultrasound guided adductor canal continuous nerve catheter using 
normal saline as bolus for placement, followed by initiation of 1/8% bupivacaine 
infusion through catheter at 8cc/h. Group 2 will receive ultrasound guided adductor 
canal nerve block with 10cc of 0.5% ropivacaine + 2mg dexamethasone (0. 5cc), 
keeping total injectate at 10.5cc to spare significant proximal spread to femoral 
nerve14. After adequate instruction including catheter education (if applicable) 
patients are to be discharged home. 
 
The following data will be collected by evaluation by study investigators via phone 
calls:   
• 
Subjective Numeric Rating Pain Scale score (NRPS) at discharge from PACU 

• 
Subjective Numeric Rating Pain Scale score (NRPS) 48 hours following 
discharge from PACU. 
• 
PONV score on POD 1 following discharge from PACU 
• 
Subjective Numeric Rating Pain Scale score (NRPS) on POD 1 and 3.  
• 
Opioid utilization based on number of pain pills (standardized dose) on POD 
1, 2, and 3.  
• 
Quadriceps strength in operative leg utilizing “Straight Leg Raise” Test, 0-5/5 
scale.  
• 
Quadriceps strength in operative leg utilizing knee extension, 0-5/5 scale.  
• 
Physical Therapy participation on POD 1.   
• 
Patient will follow up with surgeon at 6 weeks. He will do an evaluation of 
each patient's strength in operative leg and functional capacity in terms of 
ability to ambulate, as well as presence/severity of pain. Strength to be 
assessed by straight leg, knee extension, knee flexion on 5 point scale. Pain 
score on 10 point numerical scale. Ambulation: independently vs assistance, 
with or without pain, with or without gait abnormality 
 
 
7. 
Reporting of Adverse Events or Unanticipated Problems involving Risk to 
 
Participants or Others 
 
Information regarding AEs is to be obtained and documented by the surgery center 
anesthesia attending and/or the investigator performing the data collection and by 
questioning or examining the patient. All new complaints and symptoms (i.e., those 
not existing prior to signing of informed consent) will be recorded on the AE CRF.  All 
AEs will be characterized in terms of their start and stop dates, start and stop times, 
intensity, action taken, relationship to research study, subject outcome and whether or 
not the AE led to an SAE. 
 
 
8. 
Statistical Considerations 
 
Power calculations based on using 2 groups to detect a 2-point reduction in pain on 
numerical pain scale yields an 88% power. All individual data (including any relevant 
derived variables) will be stored in a password protected electronic database 
(REDCAP). 
 
 
9.       Privacy/Confidentiality Issues 
 
All reasonable efforts will be made to keep a patient’s protected health information 
(PHI) private and confidential.  There will be limited access to medical records and de-
identification of all records.  Federal privacy guidelines will be followed when using or 
sharing any protected health information.  
 
 
10.      Follow-up and Record Retention 
 
The study will be completed after the participation of 100 patients. This data will be 
used to draw conclusions about the superiority of a continuous adductor canal nerve 

catheter or long-acting saphenous nerve block versus single shot femoral nerve block. 
This information could, potentially serve as standard of care for postoperative 
analgesia for ACL reconstructions by maximizing analgesia and participation in rehab.  
 
The investigators will keep a record (i.e., Master Subject Log) relating the names of 
the subjects, date informed consent was signed, subject status, and date when subject 
completed the trial.  
 
 
1. Mulroy, MF, et al. Femoral nerve block with 0.25% or 0.5% bupivacaine improves 
postoperative analgesia following outpatient arthroscopic anterior cruciate ligament 
repair. Reg Anesth Pain Med 2001; 26 (1): 24-9. 
 
2. Ilfeld BM, Duke KB, and Donohue MC. The association between lower extremity 
peripheral nerve blocks and patient falls after knee and hip arthroplasty. Anesth Analg 
2010; 111(6): 1152-4. 
 
3. Minzer RL, Petterson SC and Snyder-Mackler L. Quadriceps strength and the time 
course of functional recovery after total knee arthroplasty. J Orthop Sports Phys Ther 
2005; 35: 424-36. 
 
4. Johnson RL, Kop SL, Hebl JR, Erwin PJ, Mantilla CB. Falls and major orthopaedic 
surgery with peripheral nerve blockade: a systematic review and meta-analysis. Br J 
Anaesth 2013; 110: 518-528. 
 
5. Jaeger P, et al. Adductor canal block versus femoral nerve block and quadriceps 
strength: a randomized, double blind, placebo-controlled, crossover study in healthy 
volunteers. Anesthesiology 2013; 118(2): 409-15. 
 
6. Jaeger P, et al. Adductor canal block versus femoral nerve block for analgesia after 
total knee arthroplasty. Reg Anesth Pain Med 2013; 38 (6): 526-32.  
 
7. Mudumbai SC, et al. Continuous adductor canal blocks are superior to continuous 
femoral nerve blocks in promoting early ambulation after TKA. Clin Orthop Relat Res 
2014; 427:  1377-83. 
 
8. Jenstrup MT, et al. Effects of adductor-canal blockade on pain and ambulation after 
total knee arthroplasty: a randomized study. Acta Anaesthesiol Scand 2012; 56 (3): 357-
384. 
 
9. Lund J, et al. Continuous adductor-canal-blockade for adjuvant post-operative 
analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand 2011; 
55 (1): 14-19. 
 
10. Espelund M, et al. The efficacy of adductor canal blockade after minor arthroscopic 
knee surgery: a randomized controlled trial. Acta Anaesthesiol Scand 2014; 58: 273-80. 
 
11. Espelund M, et al. Adductor canal blockade for moderate to severe pain after 
arthroscopic knee surgery: a randomized controlled trial. Acta Anaesthesiol Scand 2014; 
58: 1220-27. 
 

12. Espelund M, et al. Analgesic efficacy of ultrasound-guided adductor canal blockade 
after arthroscopic anterior cruciate ligament reconstruction. Eur J Anaesthesiol 2013; 30: 
422-28. 
 
13. Chisholm MF, et al. Postoperative analgesia with saphenous block appears 
equivalent to femoral nerve block in ACL reconstruction. HSSJ 2014; 10: 245-51. 
 
14. Andersen HL, Andersen SL, and Tranum-Jensen J. The spread of injectate during 
saphenous nerve block at the adductor canal: a cadaver study. Acta Anaesthesiol Scand 
2015; 59: 238-45. 
 
15.  Lewek M, Rudolph K, Axe M, and Snyder-Mackler L. The effect of insufficient 
quadriceps strength on gait after anterior cruciate ligament reconstruction. Clinical 
Biomechanics. 2002; 17: 56-63.