Effect of liquid-electric extracorporeal shock wave on treating traumatic avascular necrosis of talus

BACKGROUND: No method is ideal for treating traumatic avascular necrosis of talus up to now. Extracorporeal shock wave therapy (ESWT) is a micro-traumatic, simple, and effective method to treat musculoskeletal diseases; however, the therapeutic effect on necrosis of talus needs to be further studied. OBJECTIVE: To evaluate the therapeutic effect of liquid-electric extracorporeal shock wave on traumatic avascular necrosis of talus, and to explore new treatments of traumatic avascular necrosis of talus. METHODS: A total of 34 patients with traumatic avascular necrosis of talus were selected from the Affiliated Hospital of Medical College of Chinese Armed Police Force from September 2004 to June 2009. The patients were randomly divided into ESWT and control groups, with 17 patients per group. All patients were treated with pain point positioning combined with surface X-ray localization, the working voltage of 8-10 kV, energy flow density of 0.12-0.16 mJ/mm super(2), impact frequency of 40-50 times/min, and impact of 800-1 000 times, once a week, for 3-5 cycles. Pain was evaluated with VAS before and after treatment, function of ankle was evaluated with AOFAS standards, and MRI of ankle was re-checked at 18 months after treatment to compare necrotic area before and after treatment. RESULTS AND CONCLUSION: VAS pain, function of ankle, and necrotic area of ankle in the ESWT group were significantly improved compared to those in the control group at 18 months after treatment (P < 0.01). Activity of one case in the control group was limited by severe pain due to traumatic arthritis in the first 15 weeks after ankle arthrodesis surgery. This suggested that liquid-electric extracorporeal shock wave was a non-invasive method which was simple minimally invasive treatment and had significant effect and fewer complications, for treating traumatic avascular necrosis of talus.