Exploring The Potential Of Hyaluronic Acid Injections For Wounds

This author details how 10 patients with various types of lower extremity wounds found relief and improved ambulation following injections of hyaluronic acid.

Human feet traverse 100,000 miles in a 75-year lifespan. The cumulative effects of excessive weightbearing forces are linked to a localized loss of essential adipose tissue. Fat pad depletion results in weightbearing pain that ranges from moderate to intolerable. This places the patient at risk of a wound that can remain open for years.¹

Soft tissue augmentation has revolutionized the treatment of the aging.² The concept of utilizing materials for soft tissue augmentation actually began around 1950 with the use of liquid silicone.³ Current dermal fillers have the advantage over silicone as one can inject them in quantities sufficient to alleviate the patient’s symptoms in fewer sessions.

Hyaluronic acid is a filler that is a naturally occurring linear polysaccharide. It exhibits no species or tissue specificity. Its chemical structure is uniform throughout nature and thus has no potential for immunogenicity in its pure form. It forms the elastoviscous fluid matrix in which collagen fibers, elastic fibers and other intercellular structure are embedded.^2,4 It comes in different forms.⁵

There is a notable difference between the hyaluronic acid products. This is largely due to the amount of cross-linking that exists with these products. More cross-linking theoretically lengthens the clinical half-life of hyaluronic acid fillers. For example, Restylane (Galderma) is shorter-lasting and “smoother” than Perlane (Galderma) due to less cross-linking and a lower molecular size. Likewise, Juvederm Ultra (Allergan) and Juvederm Ultra Plus (Allergan) differ in their amount of cross-linking, which affects handling characteristics and the rate of degradation.

Another difference is the effectiveness of the products. Juvederm is advertised to last up to one year. However, the true longevity of these products varies between patients and also between anatomic locations.

A unique aspect to hyaluronic acid fillers is that one can reliably reverse a mis-injection or over-injection with hyaluronidase such as Vitrase.⁵

To obtain optimal results using fillers for soft tissue augmentation, the practitioner must be knowledgeable about several important variables.⁴ These include candidate selection, choice of filler, proper placement, amount of filler required and post-injection instructions.

The acceptable candidate must have the minimum circulation needed to heal a wound. The patient also must be able to utilize an offloading shoe or be non-weightbearing for seven to 10 days.

The ideal product would be biocompatible, non-antigenic, non-pyogenic, non-inflammatory, non-toxic, easy to use, non-migratory, long lasting yet absorbable, and affordable.⁶

A Closer Look At The Study

The study focused on 10 candidates who received Juvederm Ultra filler injections for soft tissue loss. All of the patients in the study needed to have the minimum vascular status to heal a wound. The patients all had at least one palpable pedal pulse. No vascular testing was necessary. We also deemed these patients to have the ability to remain partially non-weightbearing for seven to 10 days. All of the wounds were in areas of tissue loss and bone prominence.

All candidates received Juvederm Ultra injections in the areas of the prominences. This filler is long lasting and has a local anesthetic effect. It is free of animal products as it is biosynthesized. One can inject it in larger quantities. This reduces the number of treatments needed to achieve satisfactory results. Due to cross linking, Juvederm Ultra stays viscous in soft tissue while remaining easy to inject through a small gauge needle.^2-4,7

Proper placement of the material is essential. We placed all injections deep to the affected area. In the case of any open wounds, we started the injection from the perimeter of the wound and fanned it out over the bony prominence. 

The amount of filler required varied by patient and severity of the issue. The amount utilized ranged from 0.2 to 0.8 cc of Juvederm. 

Depending on the location of the injected area, most patients were able to utilize an offloading shoe and bear partial weight. All patients wore a post-op shoe with accommodations to the shoe. We lightly dressed the injection sites and instructed the patients to avoid any pressure at the injection site.

The patients responded well to the injections of Juvederm Ultra. All 10 patients had relief of painful symptoms and were ambulating better than prior to the injections. Three patients had injections on the contralateral foot at a later time. The average diameter of a wound or lesion was approximately 1.0 cm at baseline. The open wounds reduced in size by half at one week and closed at two weeks. Some callus lesions remained for several patients but these were not painful and reduced in size over time.

One patient was neuropathic and required multiple injections. This patient opted to have surgical intervention after two injections. Intraoperatively, the wound bed appeared to be enhanced and therefore improved the overall outcome.

At the time of publication, all patients have had a significant reduction in pain or are pain free. The open wounds have remained closed after 20 months.

In Conclusion

Advances in biomaterials continue to provide healthcare professionals with modalities that repair or replace diseased or diminished body parts.¹ Hyaluronic acid is one such material. It augments soft tissue while remaining inert and well retained. No infection, fluid rejection, inflammatory or allergic response has occurred in the study patients. Although some treated areas did not clinically look significantly improved, the level of pain was dramatically reduced.

Beyond the enormous monetary aspect of treating several million patients with these wounds annually, the physical and emotional costs to patients and their families are great. Therefore, further studies are warranted. Currently, no large scale, long-term trials have evaluated the potential benefits of this treatment approach.

Dr. Hake is affiliated with the Department of Podiatry at Ochsner Medical Center–North Shore at the Ochsner Clinic Foundation in Covington, LA.

References

1. Balkin SW. Injectable silicone and the foot: a 41-year clinical and histologic history. Dermatol Surg 2005; 31(11 Pt 2):1555-1560.

2. Brousseau-Foley M, Cantin V. Digital and interdigital corns: a report of two cases with the use of hyaluronic acid gel filter. J Am Podiatr Med Assoc. 2014; 104(4):413-416.

3. Vedamurthy M. Soft tissue augmentation-use of hyaluronic acid as dermal filler. Indian J Dermatol Venereol Leprol. 2004;70(6):384-7.

4. Narens RS, Cohen JL, Beer K. Injectable Skin Fillers. In Roenigk RK, Ratz JL, Roenigk HH (eds.) Roenigk’s Dermatologic Surgery, Third Edition, Informa Health care, New York, 2007, p. 705.

5. Kim S, Sykes J. Hyaluronic acid fillers: history and overview. Facial Plast Surg. 2011;27(6):523-8.

6. Hotta T. Dermal fillers, the next generation. Plastic Surg Nursing. 2004; 24(1):15-19.

7. Price RD, Berry MG, Navsaria HA. Hyaluronic acid: the scientific and clinical evidence. J Plas Reconstr Aesthet Surg. 2007; 60(10):1110-9.