Pelvic floor tension myalgia is a common cause of chronic pelvic pain, with approximately 50–90% of chronic pelvic pain patients having an underlying musculoskeletal etiology [9]. Trigger point injections with local anesthetic medications are important components of therapy in women who have failed conservative measures. The primary finding of this study is that PFTPI injections immediately followed by PFPT had a statistically significant improvement in VAS pain scores compared to PFTPI alone. We performed a systematic search of the PubMed database from inception to April 2022 using the terms “trigger point injections,” “physical therapy,” “myofascial pelvic pain” and “pelvic floor tension myalgia.” According to this search, our study is the first to highlight patient response to trigger point injections followed by immediate myofascial release compared to trigger point injections alone.
Treatment with either pelvic floor physical therapy or trigger point injections have yielded impressive clinical results. Pelvic floor physical therapy has been reported to improve pelvic pain symptoms in 59–80% of patients with MFPP [3] [13]. Fouad et al [4] and Bartley et al [14] also demonstrated a 65% and 77% improvement in MFFP respectively for patients who received transvaginal trigger point injections. In another study that randomized 29 women to either transvaginal trigger point injections with steroid/bupivacaine or PFPT, both groups reported significant reduction in pain [12]. Despite the overall good success rate with each treatment modality, the response can be limited and transient [5]. By combining PFTPI with immediate PFPT, there is the potential for longer-lasting reduction in pelvic pain by allowing tolerance of deeper myofascial release during the effect of anesthesia. In our study, all patients had improvement in their VAS scores; with 77% of patients in the PFTPI followed by PFPT having a change in VAS score of 3 or more. It is imperative for patients to be relaxed during their physical therapy session, thus allowing for enough manual traction on the pelvic floor muscles that will lead to effective relief of the trigger points.
The VAS score as used in this study is an effective pain assessment tool as it standardizes patient’s pain perceptions. The VAS remains one of the most widely used quantification tools for pain in published studies and is an acceptable measure of subjective pain evolution [15]. However, the minimum clinically important difference (MCID) in VAS has not been defined for pelvic pain. A clinically significant change in VAS score has been adopted from studies on chronic lower back pain where the suggested that the MCID is a VAS of at least 2 [16]. This lowest cut off value discriminates best between patients who had improvement in their pain and those whose pain intensity remains unchanged [17].
Pelvic floor dysfunction is multifactorial in etiology and affects up to 70% of women with gastrointestinal, genitourinary, and sexual disorders [18]. Women with non-relaxing pelvic floor muscle dysfunction tend to present with a recognizable pattern of symptoms including irritative voiding, chronic constipation with difficulty evacuating stool, dyspareunia, chronic pelvic pain, and low back pain [8]. In our study, the most common presenting symptoms were pelvic pain, dyspareunia, urinary, or bowel symptoms. Thirty-one percent of patients presented with urinary symptoms and 10.32% presented with bowel-related symptoms. This highlights the fact that myofascial pelvic pain rarely exists in isolation and patients should be evaluated for other treatable medical pathologies. A multidisciplinary approach with referral to specialists in gastroenterology, physical medicine and rehabilitation, sexual medicine, or urology is appropriate in some cases.
Our providers preferentially use ropivacaine due to its longer duration of clinical effect (2–6 hours) [2]. Ropivacaine is less cardiotoxic with fewer central nervous system side effects than bupivacaine [19]. Systemic toxicity risk is minimized by using a negative aspiration technique and limiting injection dose to 20 mL. In our study, 14% of patients in the PFTPI followed by PFPT received triamcinolone as part of their injected medications. A subgroup analysis showed no statistical benefit from the addition of steroid. A study by Bartley et al used steroids in 90.2% of patients but were unable to determine overall significant clinical benefit [14]. This is an area for further study, since triamcinolone has been shown to be potent in myalgia relief in non-gynecologic conditions[12]. Adverse effects of trigger point injections include inadvertent intravascular injection, syncope, localized infection, and hematomas. None of these side effects were observed in our patients during the study period.
Strengths of this study includes the fact that we were able to follow up all patients in each group and document improvement in pain after each procedure. Limitations of the study include the retrospective design and small sample size, making it vulnerable to a type II error. Additionally, follow up beyond 2 weeks would have given more information regarding the sustained improvement in pain symptoms after injections and physical therapy. We are also aware that not all centers have a pelvic floor physical therapist or clinical personnel trained in myofascial release which can limit generalizability. There is room for further research with large prospective randomized trials to determine treatment outcomes for MFFP with trigger point injections and PFPT incorporating sexual health and quality of life improvement measures.