Case Report: Acute hydrotherapy with super-saturated hydrogen-rich water for ankle sprain in a professional athlete

Introduction

Soft tissue injuries (STIs) remain among the most prevalent traumata in musculoskeletal medicine¹. Sprains, strains and contusions are common STIs that often occur during sport and exercise activities². STIs usually require immediate treatment to reduce inflammation, bleeding and damage within the injured tissue (e.g. muscle, tendon, ligaments, joint), with management options typically comprise a break from the activity that caused an injury, and different physical therapy procedures. Applying rest, ice, compression, and elevation (RICE) therapy is referred as a long standard first-aid treatment protocol for STIs³. However, insufficient evidence appears to be available to determine the relative effectiveness of RICE therapy for specific STIs⁴. In particular, RICE therapy might not be the best way to promote tissue healing due to limiting blood flow, and alternative methods and techniques are advocated to help manage STIs⁵. Among others, molecular hydrogen (H₂) has recently been put forward as a possible adjuvant treatment in musculoskeletal medicine⁶. Addition of oral and topical H₂ intervention to RICE protocol was effective to reduce inflammation and augment range-of-motion recovery in athletes who suffered a soft tissue injury⁷. However, no data are available concerning the effectiveness of hydrogen when applied as an individual first-aid intervention. This case report illustrates the efficacy and safety of acute multi-session hydrotherapy with super-saturated hydrogen-rich water for ankle sprain in a professional male athlete.

Case report

Clinical findings

At the initial examination immediately after the injury, right ankle was painful, swollen and warm, and had increased laxity on testing (Figure 1, Panel a). Self-completed visual analog scale (VAS) score for pain was 50 points (moderate pain). Figure-of-eight method of measuring ankle joint swelling at the injured ankle revealed 56.5 cm, with weight-bearing lunge test (WBLT) showing 43.1 mm. The patient demonstrated a diminished ability to bear weight.

Figure 1.

An image of sprained ankle: (a) Immediately after the injury; (b) At 24-h follow-up after six 30-min sessions of hydrotherapy with super-saturated hydrogen-rich water.

Discussion

This case report suggests the beneficial effects of hydrotherapy with hydrogen-rich water as a possible treatment to decrease pain and swelling in a professional athlete with moderate-degree ankle sprain. A number of recent animal and human studies evaluated the efficacy of H₂ in musculoskeletal medicine. H₂ appears to be effective in tackling disuse muscle atrophy in rats⁸, Duchenne muscular dystrophy in mice⁹, bone loss induced by modeled microgravity¹⁰ or ovariectomy-induced osteoporosis in rats¹¹, and mitigate disease activity in patients with rheumatoid arthritis¹². For acute injuries, hydrogen-rich saline (1 ml/100 g) seems to be beneficial in attenuating muscle damage in a rat model of skeletal muscle injury induced by 3-h tourniquet occlusion and 4-h reperfusion¹³. Our group reported advantageous effects of 2-week administration of topical and oral H₂ (added to the RICE therapy) on plasma viscosity and functional recovery in a randomized controlled trial with professional athletes who suffered STIs⁷. In this case report, we found that acute hydrotherapy with super-saturated hydrogen-rich water might be beneficial when used as the exclussive first-aid treatment in specific STIs, such as ankle sprain. H₂ positively affected STI-induced signs and symptoms at 24-h follow up perhaps due to its antioxidant, anti-inflammatory and anti-apoptotic effects¹⁴. Due to its small size and higher-grade diffusibility⁶, topical hydrogen could be easily transported to hard-to-reach tissues, including areas of injury that are often characterized by low drug penetrability¹⁵. Specifically, H₂ might prevent (or offset) the generation of toxic compounds that occur after initial injury due to subsequent cell damage and tissue hypoxia, often referred as a secondary injury¹⁶.

This professional athlete received a rather intensive treatment, with H₂ hydrotherapy applied in several recurrent episodes throughout the first 24 hours post-injury, a pattern that might be highly applicable to an athlete looking for an accelerated and efficacious strategy in STIs management and recovery³. This treatment dynamics appear to be comparable to the traditional acute RICE protocol for STIs medical care in terms of frequency (e.g. number of sessions per day) and duration of intervention (e.g. length of individual session)⁴. On the other hand, acute H₂ hydrotherapy may be superior to RICE protocol due to improved blood flow (as implied here by a decreased swelling at follow-up), while the ice component of RICE reduces blood flow to the injured area and delays healing⁵. To confirm this hypothesis, future case series should compare two interventions in a double-blind, parallel-group randomized controlled design, by evaluating peripheral circulation at the site of injury.

Due to the fact that hydrogen in water tends to evaporate over time¹⁷, hydrogen-rich water for every session was prepared fresh and administered for 30 min. A report have shown that gaseous hydrogen remains detained in water exposed to air for up to 2 hours before its concentration drops below a therapeutical level (e.g. < 1 ppm)¹⁸. The super-saturated hydrogen-rich water used here (8 ppm) perhaps provides an advantage of supraphysiological dosages of H₂ administered in a time-optimized manner. However, how H₂ concentration changes during the session of hydrotherapy remains unknown. Despite that, topical H₂ hydrotherapy yielded no side effects in our patient, confirming an affirmative safety record for H₂ reported by others [for review see Ref. 16].

Several limitations must be considered when the study findings are interpreted. First, we report a relatively short period of the intervention and post-injury assessment (e.g. 24 hours) while no medium- and long-term efficacy and safety of topical hydrogen were evaluated. Second, only limited compendium of clinician- and patient-reported outcomes were analyzed, while no biomarkers of tissue injury or inflammation were employed, and a possible mechanism of hydrogen action remains unknown. Finally, it remains open to question how topical H₂ positively affects the acute recovery of other STIs with different location, etiology and severity.

Conclusions

Even though our results are based on a single-patient report, our case has indicated that an acute multi-session hydrotherapy with hydrogen-rich water might be a safe and helpful treatment in terms of pain, swelling reduction, and regaining the range of motion after an ankle sprain. We suggest a closer monitoring of the efficacy and safety of topical H₂ therapy use in different musculoskeletal injuries on a larger similar case series.

Consent

Written informed consent was obtained from the patient for the publication of this case report, including any associated images.

Data availability