CHICAGO — Up to one-fourth of women with chronic pelvic pain also have piriformis or levator ani tenderness, according to a study presented by Dr. Frank Tu at a meeting sponsored by the International Pelvic Pain Society.
Musculoskeletal dysfunction—including tenderness and spasms of the levator ani and piriformis—has been reported as a treatable cause of chronic pelvic pain. The efficacy of treatments such as manual therapies, electrical stimulation, injected medications, and surgeries ranges from 20% to 90%, according to the literature, which is mostly comprised of case studies.
“Although musculoskeletal dysfunction is increasingly implicated as a cause of many pelvic pain conditions such as interstitial cystitis, we really don't have much information about the diagnosis, evaluation, treatment, and epidemiology of this particular condition,” Dr. Tu said. “This is the first study to look at the frequency of these disorders in a large referral clinic population.”
A retrospective study of 987 women referred to a pelvic pain clinic at the University of North Carolina, Chapel Hill, for chronic pelvic pain, found levator ani tenderness in 22% and piriformis tenderness in 13% of the 942 of patients evaluated for those conditions.
There were no differences between those with piriformis tenderness and those with levator ani tenderness in age (mean 30 years), pain duration, or sexual abuse history. Of the 987 women studied, 288 had a history of sexual abuse, said Dr. Tu, noting that the proportion of women with a history of abuse did not differ between the women with and without musculoskeletal dysfunction.
In all, 85% of patients had pain for at least 6 months, and most had daily pain. Two-thirds of the cohort had a diagnosis of depression, based on the Beck Depression Inventory.
A standardized abdominal exam was performed on all patients that included a single-digit intravaginal palpation of the levator ani and piriformis muscles, and either a Kegel contraction to identify the levators or an external hip rotation to identify the piriformis.
A visual analog score of 0-10 was assigned by the physician to rate the degree of clinically meaningful tenderness.
Piriformis and levator ani tenderness was positively associated with the number of painful abdominal-pelvic locations reported, pain associated with bowel movements, and higher Beck Depression Inventory and McGill Pain Questionnaire scores.
Patients with levator ani tenderness reported 4.6 pain locations, compared with 3.7 locations for those without such tenderness; patients with and without piriformis tenderness reported 4.6 and 3.8 pain locations, respectively.
Pain with bowel movements was reported by 372 study patients, including 51% of those with levator ani tenderness 50% of those with piriformis tenderness.
Levator ani tenderness was positively associated with a higher number of surgeries for pain. Of the 212 patients with levator ani tenderness, 23% had no previous surgeries, 61% had one-to-three surgeries, and 17% had more than three surgeries, compared with 30%, 60%, and 10%, respectively, of those without levator ani tenderness.
Neither condition was associated with pain that worsened with intercourse, although there was a trend toward a higher proportion with piriformis tenderness.
The data suggest that the prevalence of piriformis and levator ani tenderness may be increased among women with more intense chronic pelvic pain, said Dr. Tu, director of the division of chronic pelvic pain, department of ob.gyn., Evanston (Ill.) Hospital. A possible association with dyschezia also may exist.