Suprainguinal Fascia Iliaca Compartment Block in Direct Anterior Approach to Total Hip Arthroplasty

Study Design: Interventional Trial

Allocation: Randomized

Intervention Model: Parallel Assignment

Treatment groups: Group A: Control Group - DAA THA under spinal anesthesia ( standard of care at Montefiore)

Group B: Intervention Group - DAA THA under spinal anesthesia and a preoperative supra-inguinal fascia iliac compartment block (S-FICB)

Blinding Procedures:

• On the day of surgery, a sealed envelope with group allocation (Group A- Control vs. Group B - Intervention) will be opened by a team member not involved with data collection.
• For patients allocated to Group B - Intervention: A regional anesthesia block team consisting of a regional anesthesiologist, regional fellow, and resident will carry out the S-FICB in the preoperative area prior to surgery
• A separate anesthesia team consisting of an anesthesiologist and certified nurse anesthetist will be responsible for the spinal anesthetic and monitored anesthesia care for both groups in the operating room
• A separate acute pain service team will follow the patients in both groups on postoperative day 1 and evaluate sensory and motor distribution of LFCN, FN, and ON for both groups
• A research assistant blinded to the allocation of both groups will collect data from the EMR for analysis. In addition, a research assistant blinded to the allocation of both groups will call patients via telephone 24 hours post-discharge for a patient satisfaction survey.

Hypothesis: The supra-inguinal fascia iliaca compartment block will decrease 24 hours post-surgery opioid requirements in patients undergoing elective direct anterior approach to total hip arthroplasty.

Target Population: Patients undergoing primary elective total hip arthroplasty under direct anterior surgical approach

Recruitment methods: Participants who meet the inclusion/exclusion criteria for the study will be approached to participate in the study at the preoperative visit at the Orthopedic Surgeon's Office. Informed consent for participation in the study will be obtained during the preoperative visit.

The planned interventions and their timing:

• On the day of surgery, patients who have been randomized to Group B - Intervention will receive a preoperative S-FICB using 35 ml of 0.5% ropivacaine (max dose of 3mg/kg) under ultrasound guidance by the regional anesthesia block team once the patient has been marked by the surgeon
• The sensory and motor distribution of the LFCN, FN, and ON will be assessed by the regional anesthesia team in the preop area for patients randomized to the control group prior to surgery. For those patients who received a S-FICB in preop, approximately 15 minutes after the block, sensory and motor distribution of LFCN, FN, and ON will be assessed by the regional anesthesia block team prior to going to the operating room.
• All patients, regardless of group allocation, will be followed by the acute pain service team on postoperative day one to assess sensory and motor distribution of LFCN, FN, and ON and adjustment of pain medication regimens
• All patients will receive a telephone call from a research assistant blinded to group allocation 24 hours post-discharge for a patient satisfaction survey.
• Postoperatively all patients will be placed on the following pain regimen:
• All patients will be started on a Hydromorphone intravenous patient-controlled analgesia (PCA) for 24 hours, with starting parameters: 0.2mg q10 min bolus dosing without a basal rate.
• A standardized regimen of non-opioid adjuvants will include: Acetaminophen 975mg po q8h, Pregabalin 50mg po BID, Ketorolac 15mg q8h IV x 24 hours followed by Celebrex 200mg po BID.
• After the first 24 hours, patients will be transitioned off the hydromorphone PCA with oxycodone 5mg PO q4h prn for moderate pain and 10mg PO q4h prn for severe pain, hydromorphone 0.2mg IV q4h prn for breakthrough pain. These doses may be increased or decreased thereafter at the discretion of the acute pain service team based on patient evaluation and reported pain scores.

Study Population

1. Patients undergoing elective primary total hip arthroplasty under direct anterior surgical approach with neuraxial anesthesia

Participant Recruitment

Participants will be recruited during their preoperative visit to the office of the orthopedic surgery team performing the patient's surgery. At this visit, where the patient will be consented for the surgery itself, the orthopedic surgery team will present the opportunity to participate in this study during the perioperative period to patients who meet inclusion/exclusion criteria. The informed consent document will be presented to the patient at this time for review. Contact information to the study's primary investigator and anesthesia associates will be provided on the informed consent documentation if the patient should require any further information about the study. If after reviewing the study details in the consent documentation, the patient is amenable to participating, they may provide consent by signing the consent form at the orthopedic surgeon's office free from coercion. Following enrollment in the study, patient data will be collected by the primary investigator's research team, stored securely, and all patient information and data will be de-identified prior to publication.

Risks/Benefits Anticipated risks of this study include the risks associated with the S-FICB procedure itself. These include infection, bleeding, injury to surrounding structures including nerves, and local anesthetic systemic toxicity which can occur if a large amount of local anesthetic is inadvertently injected intravascularly. This procedure is performed under sterile conditions, minimizing the risk of infection. In addition, patients who have local infection at the site of injection will be excluded as participants. The risks of major bleeding is rare for patients who do not have preexisting coagulopathies, and is low for patients who are on anticoagulation that has been discontinued an appropriate amount of time prior to surgery according to the American Society for Regional Anesthesia (ASRA) guidelines. Furthermore, the risk of nerve injury is greatly mitigated using ultrasound guidance in performing this type of nerve block where nerve tissue can be identified visually. Additionally, because this is a fascial plane block, the investigators do not aim to inject local anesthetic directly adjacent to nerve structures, minimizing risk of nerve injury or damage. The use of ultrasound guidance also mitigates the risk of local anesthetic systemic toxicity as blood vessels can be visualized and avoided. The practice of frequent aspiration during injection of local anesthetic also protects against this risk.

Another risk to participants of this study is the possible loss of confidentiality; however, the investigators have designed this study to include protocols for keeping patient information private. In addition, strict storage and de-identification of data will be used to protect patient information.

This study presents several possible benefits to participants and future patients who must undergo this surgery. It presents a potential avenue for decreasing opioid requirements in the perioperative period. Adverse events associated with opioids cause significant morbidity to the patient in the postoperative period. These include nausea, vomiting, sedation and dizziness that can lead to falls during attempted ambulation and inability to participate in physical therapy, and respiratory depression requiring intervention. All of these possible events can hinder recovery significantly and contribute to longer hospital lengths of stay.

Improved pain control overall is also a potential benefit to patients participating in this study. Decreasing the levels of pain experienced by patients is often instrumental in improving a patient's satisfaction with their surgery and in-hospital recovery. Decreased pain also makes it less challenging for a patient to participate fully in physical therapy, aiding in the recovery process after major orthopedic surgery.

If the results of this study support the use of the S-FICB showing improved outcomes for patients in the postoperative period, this peripheral nerve block can be more widely employed and incorporated as part of a multimodal perioperative opioid sparing pathway to improve outcomes for this patient population in the future.

The S-FICB is a relatively low-risk procedure, while the potential benefits to participants in this study, as well as future participants, is substantial.

Randomization On the day of surgery, an envelope containing the randomization code will be given to the regional team responsible for the study patient. Patients will be randomly allocated to receive S-FICB or standard of care using a 1:1 allocation ratio. --- BMI.--- A research associate who is not directly involved with the study procedures will maintain the randomization codes.