Usefulness of a myofascial trigger point injection for groin pain in patients with chronic prostatitis/chronic pelvic pain syndrome: A pilot study

Objective: To investigate the therapeutic effectiveness of trigger point injection into the muscles around the groin in patients with clinically diagnosed chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). Design: Prospective, unicenter trial. Setting: University rehabilitation hospital. Participants: Patients (N=21) with clinically diagnosed CP/CPPS who are suspected of having myofascial pain syndrome. Intervention: Ultrasound-guided trigger point injection. Main Outcome Measures: Visual analog scale (VAS), National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score, and injection-associated complications. Results: Ultrasound (US)-guided trigger point injection of the iliopsoas, hip adductor, and lower abdominal muscles resulted in excellent outcomes. The mean values of the NIH-CPSI score decreased significantly from 20.2 pretreatment to 12.5 after the first treatment (P<.05). The mean values of VAS decreased significantly from 6.3 pretreatment to 2.9 after the first treatment (P<.05). Conclusions: In patients with CP/CPPS, US-guided trigger point injections of the iliopsoas, hip adductor, and abdominal muscles are safe and effective for both diagnosis and treatment when the cause of groin pain is suspected to originate from muscles. In particular, the iliopsoas muscle was affected in all patients in this study.