The Clinical Utility of Extracorporeal Shock Wave Therapy on Burns

In burn patients, the wound healing process may lead to a fibrotic hypertrophic scar, which is raised, inflexible and responsible functional impairments. There are few studies which have investigated the effect of extracorporeal shock wave therapy (ESWT) on hypertrophic scar characteristics using objective measurements. Thus, this study aimed to ascertain the effects of ESWT on burn scars using objective measurements. This double-blinded, randomized, controlled trial involved 36 patients with burns. Patients were randomized into a ESWT (an energy flux density (EFD) of 0.05 to 0.30 mJ/mm2, frequency of 4Hz, and 1000 to 2000 impulses) or a sham stimulation group. Each intervention was applied to the hypertrophic scars of upper extremities after autologous split-thickness skin grafting (STSG) using Materiderm for 4 weeks once per week. The ESWT group (n=18) received shock waves with low-energy flux density (0.05-0.30 mJ/mm2). The interval between treatments is a 1-week. The ESWT group also received standard treatment. The control group (n=18) received sham stimulation with standard treatment. The investigators compared the skin quality of the ESWT and control groups. Participants were made comfortable and acclimatized to room conditions. Room temperature was maintained at 20-25'C and relative humidity at 40-50 %. In the supine position, skin properties were measured. The thickness was measured with a ultrasonic wave equipment (128 BW1 Medison, Korea). Mexameter® (MX18, Courage-Khazaka Electronics GmbH, Germany) was used to measure melanin levels and the severity of erythema. The higher values indicating a darker and redder skin. TEWL was measured with a Tewameter® (Courage-Khazaka Electronic GmbH, Germany), which is used for evaluating water evaporation. Sebum in the scars was measured with the Sebumeter® (Courage-Khazaka Electronic GmbH, Germany). The measurement is based on the principle of grease-spot photometry using a cassette with its special tape. A microprocessor calculates the result, which is shown on the display in mg/cm2. Elasticity was measured using Cutometer SEM 580® (Courage-Khazaka Electronic GmbH, Cologne, Germany), which applies negative pressure (450 mbar) on the skin. The numeric values (mm) of the skin's distortion is presented as the elasticity. Two seconds of negative pressure of 450 mbar is followed by 2 s of recess, and this consists of a complete cycle. Three measurement cycles were conducted, and the average values were obtained.

• Extracorporeal shock wave therapy (Other): ESWT was conducted using the Duolith SD-1® device (StorzMedical, Tägerwilen, Switzerland) with an electromagnetic cylindrical coil source for the focused shock wave (Fig. 2). ESWT was performed around the primary treatment site at 100 impulses/cm2, an energy flux density(EFD) of 0.05 to 0.30 mJ/mm2, frequency of 4Hz, and 1000 to 2000 impulses were administered at 1-week intervals for 4 sessions.
• conventional occupational therapy (Other): Standard accupational therapy consist of range of motion exercise, strengthening exercises, and activities of daily living exercises

Primary outcomes

• scar thickness [4 weeks]: The thickness was measured with a ultrasonic wave equipment

Secondary outcomes

• skin darkness [4 weeks]: the degree of pigmentation and melanin level, the higher values indicating a darker(AU)
• skin reddness [4 weeks]: the degree of erythema, the higher values indicating a redder skin(AU)
• skin dryness [4 weeks]: evaluating the degree of water evaporation(g/h/m2). the higher values indicating a skin dryness
• sebum level [4 weeks]: measurement is based on the principle of grease-spot photometry using a cassette with its special tape. A microprocessor calculates the result, which is shown on the display in mg/cm2
• Elasticity [4 weeks]: which applies negative pressure (450 mbar) on the skin. The numeric values (mm) of the skin's distortion is presented as the elasticity. Two seconds of negative pressure of 450 mbar is followed by 2 s of recess, and this consists of a complete cycle. Three measurement cycles were conducted, and the average values were obtained

Sex: All, ages: 18 Years to 70 Years

Inclusion Criteria:

* aged ≥18 years
* deep partial-thickness (second-degree) burn or a full thickness (third-degree) burn
* less than 6 months since the onset of the burn injury

Exclusion Criteria:

* history of cancer
* fourth-degree burns (involving muscles, tendons, and bone injuries)
* musculoskeletal diseases (fracture, amputation, rheumatoid arthritis, and degenerative joint diseases)
* pregnancy
* if there was potential for additional damage to the skin due to the use of ESWT and conventional occupational therapy

• Results publication: Cui HS, Hong AR, Kim JB, Yu JH, Cho YS, Joo SY, Seo CH. Extracorporeal Shock Wave Therapy Alters the Expression of Fibrosis-Related Molecules in Fibroblast Derived from Human Hypertrophic Scar. Int J Mol Sci. 2018 Jan 2;19(1):124. doi: 10.3390/ijms19010124. PMID 29301325
• Results publication: Saggini R, Saggini A, Spagnoli AM, Dodaj I, Cigna E, Maruccia M, Soda G, Bellomo RG, Scuderi N. Extracorporeal Shock Wave Therapy: An Emerging Treatment Modality for Retracting Scars of the Hands. Ultrasound Med Biol. 2016 Jan;42(1):185-95. doi: 10.1016/j.ultrasmedbio.2015.07.028. Epub 2015 Oct 9. PMID 26454624