Clinical utility of extracorporeal shock wave therapy in restoring hand function of patients with nerve injury and hypertrophic scars due to burns: A prospective, randomized, double-blinded study

Background: Joint contractures and nerve injuries are common after hand burns. Extracorporeal shock wave therapy (ESWT) is effective not only for the regeneration of various tissues, including scar tissues, but also for reducing pain and pruritus in patients with burns. Researchers have attempted to explore the effects of ESWT on hand dysfunction caused by nerve injury following burns. Materials and methods: We evaluated the effects of ESWT (compared to sham stimulation) on hands with nerve injury and hypertrophic scars and thereby on hand function. The current study was a double-blind randomized controlled trial involving 120 patients. The ESWT parameters were as follows: energy flux density, 0.05–0.30 mJ/mm 2 ; frequency, 4 Hz; 1000 to 3000 impulses per treatment; and 12 treatments, one/week for 12 weeks. Outcome measures were as follows: 10-point visual analog scale for pain, Jebsen-Taylor hand function test, grip strength, Purdue Pegboard test, ultrasound measurement of scar thickness, and skin characteristics before and immediately after 12 weeks of treatment. Results: No significant inter-group difference was noted after the initial evaluation ( P >0.05). More significant improvements were found in the ESWT group than in the sham group in terms of the VAS score ( P =0.004), extension ROMs of hand joints ( P =0.02), the JTT scores (writing, small, and light) ( P <0.001, P <0.001, and P =0.002), and skin characteristics (melanin, skin distensibility, and biologic skin elasticity) ( P =0.004, P <0.001, and P <0.001). Other measured outcomes did not differ between the two groups after the treatment. Conclusion: We identified the clinically beneficial effects of ESWT in promoting hand function, improving scarring, and alleviating scarring-related pain, thereby highlighting its advantages in improving hand function that has been impaired due to nerve injury and hypertrophic scars after burns.