“Hypertrophic burn scars often lead to functional impairment in patients due to the loss of elasticity in the scar tissue,” explains Peter Moortgat, BSc. “The optimal time to intervene and prevent these impairments is within the first 6 months after wound closure. However, due to the fragility of the scarred skin, treatment options within the first 3 months after wound closure are limited, resulting in a loss of 3 months in which to prevent these impairments. Although a wide variety of non-invasive treatments have been proposed for the management of hypertrophic burn scars, reported efficacy for these treatments has been inconsistent.”

For a paper published in Scars, Burns & Healing, Moortgat and colleagues examined the objective and subjective scar-related effects of extracorporeal shock wave therapy (ESWT), a relatively new type of mechanotherapy for the treatment of wounds and scars in the early remodeling stage. “ESWT can be used on fragile, scarred skin within the first 3 months after wound closure, since it is non-invasive,” says Moortgat. “It has also been shown to improve elasticity within the first 3 months.”

First of Its Kind Study

In the first study of its kind to investigate the effects of ESWT on the elasticity of burn scars, patients were randomly assigned the low-energy intervention group or the placebo control group, and were tested at baseline, and after 1, 3, and 6 months. All patients were treated with pressure garments, silicone, and moisturizers. Both groups received ESWT treatment (real or placebo) once weekly for 10 weeks. Scars were subjectively assessed for quality by the patient and an observer using the Patient and Observer Scar Assessment Scale (POSAS). Objective assessments included measurements of redness, water loss, and elasticity.

After adjusting for baseline values, the researchers observed a mean difference of 0.23 mm for elasticity between the groups at 6 months, in favor of ESWT. “With mean scar ages of 2.7 and 2.4 months in the ESWT and placebo groups, respectively, the study showed that ESWT presented better results than placebo in improving elasticity of young burn areas,” Moortgat says. “Low-intensity ESWT offers added value to the non-invasive treatment of patients with hypertrophic burn scars with a risk for functional impairments, specifically to improve elasticity in the early stages of healing.”

Preventing Pathological Scar Development

The findings show that both treatment groups experience improvements over time on all parameters, notes Moortgat. “However, elasticity was the only parameter for which the shock wave group performed significantly better than the placebo group,” he adds. “For the other parameters—redness and water loss—both groups showed significant improvements, but these were due to the natural evolutive character of the healing process. For elasticity, the shock wave group exceeded that natural evolutive character (Table).”

This research provides clinicians with a new weapon in the battle of against pathological scarring with functional impairments, according to Moortgat. “Within the first 3 months after wound closure, pressure garments and silicone often lead to maceration of fresh scars,” he says. “Applying low-intensity shock wave therapy could prevent pathological development of the scar.”

Moortgat and colleagues express the need for further research on the benefits of ESWT for burn scars. “Future studies should focus on long-term outcomes (up to 1 year), comparing different intensities of shock wave therapy,” Moortgat says. “We would also be interested in seeing research conducted on burn scars that have been present for more than a year. Performing the same study on linear (surgical) scars would also be welcome.”