Trigger Point Injections for Post-Mastectomy Pain Syndrome: A Protocol for a Randomized Double-Blind Clinical Trial (NCT04267315)

INTRODUCTION Post-Mastectomy Pain Syndrome (PMPS) refers to a condition of chronic pain persisting for more than three months after a breast surgical procedure. It affects 11 to 70% of individuals with breast cancer. The pain has a mixed etiology, often with the frequent presence of associated myofascial pain. Trigger Point Injection (TPI) is a well-established procedure in the treatment of myofascial pain in the general population. However, there are no controlled studies evaluating the efficacy of TPI in the treatment of PMPS. OBJECTIVE To evaluate the efficacy of TPI in individuals with PMPS when combined with interdisciplinary rehabilitation and pharmacological treatment. METHODS This is the protocol for a double-blind, placebo-controlled clinical trial. Both groups will receive routine care by a Physiatrist and Rehabilitation Team blinded to the allocation. The active group will receive Trigger Point Injections with 1% lidocaine at each identified trigger point once a week for up to three consecutive weeks. The control group will receive subcutaneous infiltrations of saline at the same points and frequency. This protocol was registered at the ClinicalTrials.gov website ( NCT04267315 ). STATISTICAL ANALYSIS Analysis of Covariance (ANCOVA) for between-group differences at baseline, one month, and three months for pain, central sensitization, and functionality (n=120). A significance level of alpha=5% and statistical power of 80% will be employed.