the Efficacy of Hyperbaric Oxygen on Acute Ankle Sprain

A Multicenter, Prospective Clinical Randomized Controlled Study of the Efficacy of Hyperbaric Oxygen on Acute Ankle Sprain

Investigators recruited 208 patients with acute ankle sprain who were from the Rehabilitation Department of the Second Affiliated Hospital of Zhejiang University, School of Medicine from January 2026 to November 2028. Perform the improvement in AOFAS scores and Baird-Jackson ankle scores study and Rehabilitation assessments followed up after 3 years.

Study Overview

• Status: Not yet recruiting
• Conditions: Ankle Sprain
• Intervention / Treatment: Other: hyperbaric oxygen therapy; Other: non Hyperbaric Oxygen Therapy

Detailed Description

In baseline, 208 patients with i acute ankle sprain were recruited from the Rehabilitation Department of the Second Affiliated Hospital of Zhejiang University School of Medicine from January 2026 to December 2028, and were followed up after 3 years.

Perform the improvement in AOFAS scores and Baird-Jackson ankle scores study and Rehabilitation assessments followed up after 3 years. The Hyperbaric oxygen group treatment was administered at an atmospheric pressure of 2 ATA, with 100% oxygen inhalation. Oxygen was inhaled for 40 minutes (20 minutes of oxygen inhalation, 5-minute rest, 20 minutes of oxygen inhalation, decompression), once daily for 14 consecutive days. The control group treatment at an atmospheric pressure of 1.4 ATA, inhaling 21% oxygen by volume. Oxygen inhalation schedule: 40 minutes (inhale oxygen for 20 minutes, rest for 5 minutes, inhale oxygen for 20 minutes, decompression), once a day for 14 consecutive days.

Two person analyzed the above data, and record abnormal results.

• Study Type: Interventional
• Enrollment (Estimated): 208
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Bing Xiong, MD; Phone Number: 86-13516803156; Email: 2202030@zju.edu.cn

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Unilateral ankle sprain;
• Swelling, bruising, and pain at the site of the sprain;
• Injury occurring within 72 hours;
• MRI examination clearly shows ligament damage.

Exclusion Criteria:

• X-ray shows ankle fracture;
• Ankle has skin lesions or skin diseases;
• History of lower limb and pelvic surgery;
• Obvious neurological or psychiatric disorders that may interfere with assessment;
• Severe ligament injuries or joint instability requiring surgical treatment;
• Previous ankle injuries, persistent pain or functional limitations;
• Pneumothorax, severe emphysema, active bleeding, or other diseases with contraindications for hyperbaric oxygen therapy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: hyperbaric oxygen group; The treatment is administered at an atmospheric pressure of 2 ATA, with 100% oxygen inhalation.	Other: hyperbaric oxygen therapy; The treatment is administered at an atmospheric pressure of 2 ATA, with 100% oxygen inhalation. Oxygen inhalation time: 40 minutes (inhaling oxygen for 20 minutes, resting for 5 minutes, inhaling oxygen for 20 minutes, decompression), once daily, for 14 consecutive days. (Commenced immediately after randomisation)
Sham Comparator: non hyperbaric oxygen group; The treatment is administered at an atmospheric pressure of 1.4 ATA with an inhaled oxygen fraction of 21%	Other: non Hyperbaric Oxygen Therapy; The treatment is administered at an atmospheric pressure of 1.4 ATA with an inhaled oxygen fraction of 21%, oxygen inhalation time: 40 minutes (20 minutes of oxygen inhalation, 5 minutes rest, 20 minutes of oxygen inhalation, decompression), once daily, for 14 consecutive days. (Commences immediately after randomisation)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AOFAS score	Improvement of American Orthopaedic Foot & Ankle Society Score （AOFAS scores）in acute ankle sprains with early HBO treatment. Usually scored from 0 to 100, higher scores mean a better outcome.	3 years
Baird-Jackson ankle score	Improvement of Baird-Jackson Ankle Evaluation Score（Baird-Jackson ankle scores） in acute ankle sprains with early HBO treatment. Usually scored from 0 to 100., higher scores mean a better outcome.	3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pain scores	The effects of hyperbaric oxygen on improvements in pain scores Visual Analog Scale (VAS) (resting VAS and walking VAS) in patients with acute ankle sprain. Usually scored from 0 to 10. higher scores mean a worth outcome.	3 years
ankle swelling	Measure the ankle joint circumference at the level of the medial malleolus tip, in millimeters, on both the affected and healthy sides, and calculate the degree of swelling. The more swollen the joints, the worth the outcome.	3 years
high-frequency ultrasound findings	Observe the damage and healing of ligaments and surrounding tissues. The better the continuity of the ligaments and surrounding tissues, the better the outcome.	3 years
Ankle MRI	Observe the damage and healing of ligaments and surrounding tissues. The higher the MRI signal, the worse the outcome.	3 years
patient's overall evaluation of treatment (PGIC)	The doctor asks the patient about their overall feeling regarding the treatment: 'Has there been any improvement?' Choose one as your answer: Number 1 indicates significant improvement; Number 2 indicates slight improvement; Number 3 indicates no change; Number 4 indicates worsening due to the treatment. higher scores mean a worth outcome.	3 years
HAMA scale score	the effects of hyperbaric oxygen on change in Hamilton Anxiety Scale（HAMA scale score）in patients with acute ankle sprain. Each item is rated on a five-point scale from 0 to 4. The total score reflects the overall severity of anxiety and can be used to assess treatment effects and changes in the condition. Total score ≥29: Possible severe anxiety. Total score ≥21: Definitely significant anxiety. Total score ≥14: Definitely anxiety. Total score ≥7: Possible anxiety. Total score <7: No anxiety symptoms. higher scores mean a worse outcome.	3 years

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University
• Investigators: Principal Investigator: Bing Xiong, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, China

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): March 1, 2029
• Study Completion (Estimated): March 1, 2029

Study Registration Dates

• First Submitted: January 20, 2026
• First Submitted That Met QC Criteria: February 11, 2026
• First Posted (Actual): February 12, 2026

Study Record Updates

• Last Update Posted (Actual): February 12, 2026
• Last Update Submitted That Met QC Criteria: February 11, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: hyperbaric oxygen; acute ankle sprain
• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Ankle Injuries; Therapeutics; Respiratory Therapy; Oxygen Inhalation Therapy; Hyperbaric Oxygenation
• Other Study ID Numbers: 2025-1461

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