Popliteal Nerve Block for Acute Achilles Tendon Rupture Repair Surgery

The Effects of Popliteal Nerve Block on Pain and Nerve-Related Symptoms After Acute Achilles Tendon Rupture Repair Surgery: A Randomized Controlled Trial

Achilles tendon rupture is common, yet the value of popliteal nerve block for postoperative pain control during surgical repair remains uncertain. Despite widespread use, evidence supporting its analgesic effectiveness is limited, and both popliteal nerve block and Achilles tendon repair carry risks of nerve injury. This randomized, placebo-controlled trial will evaluate whether adding a popliteal nerve block to standard systemic analgesia improves postoperative pain and reduces opioid use in patients undergoing acute Achilles tendon rupture repair. Secondary outcomes will examine the incidence and impact of nerve complications on recovery, including return to physical activity and functional performance.

Study Overview

• Status: Recruiting
• Conditions: Acute Achilles Tendon Rupture
• Intervention / Treatment: Procedure: Popliteal Nerve Block; Procedure: Sham Block

Detailed Description

This will be a prospective, double-blinded, randomized controlled superiority trial conducted at Women's College Hospital (WCH). The study aims to enroll 80 patients (40 per group) undergoing ambulatory surgical repair of acute Achilles tendon ruptures.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Didem Bozak; Phone Number: 416-323-6008; Email: didem.bozak@wchospital.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5S 1B2
      • Recruiting
      • Women's College Hospital
      • Principal Investigator: Richard Brull, MD,FRCPC
      • Contact: Didem Bozak; Phone Number: 416-323-6008; Email: didem.bozak@wchospital.ca
      • Sub-Investigator: Connor TA Brenna, MD
      • Sub-Investigator: Seung C Kim, MD,FFPMRCA
      • Sub-Investigator: Faraj W Abdallah, MD,FRCPC
      • Sub-Investigator: Sam Park, MD,MASc

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 - 65
• ASA classification: I - III
• BMI < 35 kg/m2
• Undergoing acute Achilles tendon rupture repair surgery as a day surgery procedure

Exclusion Criteria:

• Pre-existing neurological deficits or peripheral neuropathy in the distribution of the tibial or common peroneal nerves
• Local infection
• Contraindication to regional anesthesia (e.g., bleeding diathesis, coagulopathy)
• History of use of over 30 mg oxycodone or equivalent per day
• Contraindication to any component of a standard multi-modal analgesia
• Allergy to local anesthetics
• History of significant psychiatric conditions that may affect patient assessment
• Pregnancy
• Inability to provide informed consent
• Patient refusal of popliteal nerve blockade
• Prior Achilles tendon surgeries on the operative leg
• Unable to speak or read English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Popliteal nerve (PN) block group; 30 mL of 0.5% ropivacaine with 2.5 µg/ml of epinephrine	Procedure: Popliteal Nerve Block; Under ultrasound guidance, a 22G, 80-mm echogenic needle (SonoTAP II, Pajunk Medical Systems, USA) will be inserted using an in-plane lateral-to-medial approach. 30 mL of 0.5% ropivacaine with 2.5 µg/ml of epinephrine will be deposited between tibial and common peroneal nerves within the paraneural sheath. Adequate spread of local anesthetics will be confirmed by visualization of paraneural spread.; Other Names: Popliteal Sciatic Nerve Block
Sham Comparator: Placebo Nerve Block; 1 mL of saline	Procedure: Sham Block; Patients in the Control group will receive sham blocks using a 25G needle to inject 1 mL of saline subcutaneously in the same location (popliteus of the surgical knee). Sterilization and ultrasound scanning will match actual PN block. Such a non-invasive placebo allows maintaining patient blinding, while reducing the risks associated with high-volume placebo nerve block injections. The ultrasound screen will be blinded from the patient's vision for all patients in the trial to prevent unblinding by patients with knowledge of the technique.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cumulative Opioid Consumption	Total opioid dose administered to each patient, converted to oral morphine equivalents.	The first 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse Events Attributable to Opioids	The incidence of opioid-related side effects, including sedation, pruritis, nausea/vomiting, and respiratory depression.	Evaluated at 24 and 48 hours after surgery.
Area Under the Curve for Postoperative Pain	Area under the curve calculated from discrete Numeric Rating Scale evaluations of postoperative pain (0 - 10), where 0 corresponds to no pain, and 10 corresponds to the worst pain imaginable. Pain will be measured on this scale at 0, 6, 12, 18, and 24 hours after surgery.	The first 24 hours after surgery
Quality of Recovery	Quality of recovery evaluated using the QoR-15 scale (0 - 150), where 0 represents extremely poor recovery and 150 represents excellent recovery.	At baseline, 6, 24, 48 hours, 7 days and 1-year post-surgery
Postoperative Pain Score	Measured using the Numeric Rating (NRS) Scale (0 - 10) where 0 corresponds to no pain, and 10 corresponds to the worst pain imaginable.	At baseline, 0, 6, 12, 18, 24, 36, 48 hours, 7 days and 1-year post-surgery.
Intraoperative Opioid Consumption	Measurement of opioids administered during surgery, converted into oral morphine equivalents.	The first 24 hours after surgery
Time to Analgesic Request	Length of time until the patient's first request for analgesics following surgery.	The first 24 hours after surgery
Time to Discharge	The length of time each patient stays in Phase I (Postanesthesia Care Unit) and Phase II (Surgical Day Care) after surgery.	The first 24 hours after surgery
Adverse Events Attributable to Popliteal Block	The incidence of adverse events possibly attributable to popliteal nerve block, including peripheral nerve injury, hematoma, and infection.	At 0, 6, 12, 18, 24, 36, 48 hours, 7 days and 1-year post-surgery
Pain, fatigue, and physical function	Measured using the Achilles tendon Total Rupture Score (ATRS)	Prior to surgery and 1-year post-surgery
Neuropathic pain	Measured using the English version of the Douleur Neuropathique 4 (DN4) Questionnaire	At 1 week and 1-year post-surgery

Collaborators and Investigators

• Sponsor: Women's College Hospital
• Investigators: Principal Investigator: Richard Brull, MD, FRCPC, University Health Network, Toronto

Publications and helpful links

General Publications

• Brenna CTA, Khan S, Abdallah FW, Brull R. Achilles Hero or Heel? A Systematic Review of Popliteal Nerve Block for Achilles Repair. Foot & Ankle Surgery: Techniques, Reports & Cases. 2025:100474.

Study record dates

Study Major Dates

• Study Start (Actual): March 17, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): March 1, 2028

Study Registration Dates

• First Submitted: March 14, 2025
• First Submitted That Met QC Criteria: March 14, 2025
• First Posted (Actual): March 20, 2025

Study Record Updates

• Last Update Posted (Actual): April 23, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Achilles Tendon; Popliteal Nerve Block; Lower Extremity Regional Anesthesia
• Additional Relevant MeSH Terms: Wounds and Injuries; Rupture
• Other Study ID Numbers: 2025-0039-B

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No