Pilot Study on Pain and Sensation After Regional Anesthesia for Total Hip Arthroplasty
Conditions: Anesthesia, Conduction, Osteoarthritis, Hip
Sponsor: Wake Forest University Health Sciences

Study Title: Pilot Study on Pain and Sensation after Regional Anesthesia for Total Hip 
Arthroplasty 
NCT Number: NCT03623035 
Document Date: July 30, 2018 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Study Title: Pilot Study on Pain and Sensation after Regional Anesthesia for Total Hip 
Arthroplasty 
 
Principal Investigator(s):  Christopher J. Edwards MD 
 
Sponsor or funding source: Department of Anesthesiology at Wake Forest University Baptist 
Hospital.   
 
Background, Rationale and Context 
Total hip arthroplasty (THA) remains one of the most successful orthopedic procedures in that it 
can effectively relieve pain and restore function in patients with end stage osteoarthritis1.  In an attempt to 
accelerate recovery, many orthopedic surgeons have opted to utilize a direct anterior approach (DAA) as 
opposed to the more traditional posterolateral approach (PLA).  The literature supports that DAA is 
superior to PLA with regard to lower blood loss, less pain, shorter hospital stay, and faster rehabilitation.  
The DAA technique involves dissection of muscular planes for insertion of components resulting in less 
tissue damage as compared to PLA2.  For this reason, we are seeing more DAA total hip arthroplasty 
procedures performed at our institution. 
 
Traditionally, we perform Lumbar Plexus blocks (LPB) in a manner consistent with that 
described by Capdevila et. al3 to provide post-operative analgesia for total hip arthroplasty.  This 
technique works well for the traditionally performed PLA in that the hip joint and incision site are within 
the analgesic distribution of the LPB.  Conversely, the DAA utilizes an anterior incision that overlies the 
L1 and L2 dermatomes as opposed to the lower lumbar dermatomes of the PLA incision.  The incision 
runs proximal to distal starting 3cm distal to and 3cm lateral to the anterior superior iliac spine.4 When 
performing LPB, it has been our clinical experience that it is rare to achieve analgesia in the proximal 
distribution of the lumbar plexus resulting in apparent sparing of the L1 and L2 nerve root distributions.   
 
The Quadratus Lumborum block (QLB) is a newer regional analgesic technique that may be as 
effective as LPB at providing pain control following DAA hip arthroplasty.  The QLB as described by 
Børglum is thought to provide analgesia by blocking both the lateral and anterior cutaneous branches of 
T7 through L4.5  This degree of dermatomal coverage suggests that QLB could be an efficacious 
alternative to LPB for DAA hip arthroplasty.  To the best of the authors’ knowledge, there has been no 
investigation comparing the efficacy, with regards to post-operative pain management, between LPB and 
QLB.   
 
Analgesic modalities commonly employ primarily opioid therapy, however there is increased 
attention in the literature that supports minimizing opioid related adverse effects using multimodal 
analgesic therapies and avoiding an increase in the use of known agents that contribute substantially to 
adverse effects, including post-operative nausea and vomiting, hypoxia, and urinary retention.  In 
contrast, analgesia provided by regional anesthesia results in a decreased risk of the aforementioned 
complications.6 It is therefore postulated that, at minimum, analgesic efficacy would be comparable, and 
potentially improved for DAA procedures through the use of a QLB versus LPB.   
 
In order to compare a QLB to a LPB, we must first assess patient pain scores 6 hours after 
receiving a LPB and spinal anesthetic (both are considered a practice standard for our institution) for 
DAA procedures. We also want to test the presence or absence of pin prick sensation at the base of the 1st 
toe (L5 dermatome) and the base of the 5th toe (S1 dermatome) 6 hours postoperatively. This will allow us 
to assess for spinal resolution below the level of the lumbar plexus. Intact sensation at L5 and/or S1 in 
addition to a demonstrable lumbar plexus block would indicate that the pain scores obtained at 6hrs would 
represent analgesia provided by the lumbar plexus block alone. 

 
Objectives 
The purpose of this study is to collect pilot data to help the design of a future randomized study, 
comparing a QLB to a LPB for DAA procedures. We will collect pain scores measured on a 
visual analog scale at 6hrs.  Additionally, we will assess for spinal resolution below the level of 
L5/S1 by assessing the presence of absence of pin prick sensation at these levels.  This will help 
determine if pain scores collected at 6hrs reflect analgesia provided by the preoperative LPB 
alone or if the data is confounded by the presence of spinal anesthesia.  This data will help us 
determine if 6hrs is a feasible primary endpoint to assess pain scores.  Additionally, assuming 
that spinal regression is complete by 6hrs, the VAS pain scores obtained will then be used to 
perform a power analysis to determine the necessary study size when comparing QLB to LPB for 
DAA hip arthroplasty. 
 
Methods 
Study staff will visit 10 patients, at their hospital rooms, 6 hours after a LPB and spinal block are 
performed for their DAA hip surgeries. Patients will be asked to verbally rate their pain, on a 
scale from 0 to 10, when resting and when they sit up in bed. Study staff will use a blunt needle 
to touch the base of the 1st toe (L5) and the base of the 5th toe (S1), without breaking the skin. 
Patients will be asked if they can feel “pinprick,” touch, pressure, or nothing.    
 
Setting 
All participating patients will receive their surgeries at Davie Medical Center of Wake Forest 
Baptist Health.  
 
Subject Selection 
Inclusion 
Patients will be eligible for inclusion in the study if they are at or over the age of 18 years 
old and have elective total hip arthroplasty with DAA at Davie Medical Center. 
 
Exclusion 
Patients will be excluded if they do not receive a lumbar plexus block and spinal 
anesthesia and/or if they have peripheral neuropathy effecting their feet. 
 
Interventions 
Interventions are limited to a pin prick sensation testing at the base of the 1st toe and of the 5th 
toe.  
 
Outcomes: 
Outcomes will include patient pain scores (rest and with activity) and the presence or absence of 
pin prick sensation 6 hours post LPB placement. 
 
Human Subject Protection 
 
Informed Consent 
No informed consent will be obtained as patients will not be prospectively enrolled in this 
study, and no patient information will be obtained or otherwise collected. 
 

Confidentiality and Privacy 
The only information taken for this study will be pain scores and presence or absence of 
sensation. No patient identification numbers or characteristics will be collected. Patients 
will be referred to by a simple number (numbers 1 through 10). 
 
 
Data and Safety Monitoring 
The principal investigator will be responsible for the overall monitoring of the data and safety of 
study participants.  The principal investigator will be assisted by other members of the study 
staff. 
  
Reporting of Unanticipated Problems, Adverse Events or Deviations 
Any unanticipated problems, serious and unexpected adverse events, deviations or protocol 
changes will be promptly reported by the principal investigator or designated member of the 
research team to the IRB and sponsor or appropriate government agency if appropriate. 
 
References 
1. Laupacis A, Bourne R, Rorabeck C, Feeny D, Wong C, Tugwell P, et al. The effect of 
elective total hip replacement on health-related quality of life. J Bone Joint Surg Am 
1993;75:1619e26 
2. H Zhao, P Kang, Y Xia, X Shi, Y Nie, F Pei, Comparison of Early Functional Recovery 
After Total Hip Arthroplasty Using a Direct Anterior or Posterolateral Approach; A 
Randomized Controlled Trial.  J Arthroplasty. 2017 Jun 8. pii: S0883-5403(17)30496-5. 
doi: 10.1016/j.arth.2017.05.056 
3. Capdevila X, Macaire P, Dadure C, Choquet O, Bibioulet Ph, Ryckwaert Y, d’Athis F. 
Continuous psoas compartment block for postoperative analgesia after total hip 
arthroplasty:  New landmarks, technical guidelines, and clinical evaluation.  Anesth Analg 
2002;94:1606-1613 
4. ZD Post, F Orozco, C Diaz-Ladezma, WJ Hozack, A Ong, Direct anterior approach for 
total hip arthroplasty:  indications, technique, and results.  J Am Acad Orthop Surg 2014: 
22(9): 595-603 
5. Børglum J, Moriggl B, Jensen K, Lӧnnqvist PA, Christensen AF, Sauter A, Bendtsen TF. 
Ultrasound-guided transmuscular quadratus lumborum blockadge. Br J Anaesth 25 March 2013 
6. Williams BA, Kentor ML, Vogt MT, Vogt WB, Coley KC, Williams JP, Roberts MS, Chelly JE, 
Harner CD, Fu FH. Economics of Nerve Block Pain Management after Anterior Cruciate 
Ligament Reconstruction.  Anesthesiology 2004;  100(3): 697-706