Pelvic floor muscles (PFMs) undergo considerable stretching during vaginal birth. In 21% of women, stretching results in levator ani muscle (LAM) avulsion, a disconnection of the muscle from the pubic symphysis [1]. Avulsion has serious consequences, as it is associated with higher risk of urinary incontinence (UI) and the development of other pelvic floor disorders. International clinical guidelines recommend multimodal physiotherapy treatment (MPT) including PFM training, as a first-line treatment for UI. However, no study has yet determined whether women sustaining this injury can benefit from MPT. Therefore, the aim of this study was to evaluate the efficacy of MPT for reducing UI, compared to a control group (CG), in women with a LAM avulsion. Secondary objectives were to compare the effects of MPT versus CG on symptoms and associated impact of pelvic floor disorders and impression of change.

We conducted a multicenter, parallel-group, randomized controlled trial. Women aged 18-45 years with stress or mixed UI were included if they had a LAM avulsion diagnosed using 4D transperineal ultrasound following a validated procedure [2]. Women were randomly assigned (1:1) to receive either weekly sessions of MPT (including education, PFM training with biofeedback and home exercises) or relaxation massage therapy (GC) for 12 weeks. Randomization was stratified by center (three) and avulsion severity (unilateral and bilateral) using a concealed computer-generated list managed by an independent researcher. Evaluations were carried out at baseline, after treatment and at 9-month follow-up by assessors blinded to group allocation. The primary outcome was the percentage reduction in UI episodes, assessed with the 7-day bladder diary [3]. Secondary outcomes included symptoms and associated impact of pelvic floor disorders (ICIQ-UI-short form, Pelvic Floor Distress Inventory (with UDI, POPDI, CRADI subscales), Pelvic Organ Prolapse Symptom Score and Pelvic Floor Impact Questionnaire) and impression of change (Patient’s Global Impression of Change). The a priori sample size calculation determined that 124 participants were required to detect a clinically important difference of a 20% reduction in UI episodes (SD34%, α=0.05, and power=80%), while accounting for a 25% dropout rate. Intention-to-treat analyses were conducted using ANCOVA for the primary outcome, adjusted for center, avulsion severity, and baseline UI. Secondary outcomes were analyzed using piecewise linear growth models and Fisher’s exact tests.

Of the 322 women recruited, 126 participants diagnosed with avulsion (75 unilateral and 51 bilateral) were randomized to MPT or CG. Among these, 120 (95%) completed the post-treatment evaluation, and 114 (90%) completed the 9-month follow-up. MPT was more effective than CG for reducing UI at post-treatment (MPT -70.0%±35.9 vs CG -26.7%±43.9; mean difference between groups 43.5% [95%CI 29.0-58.0]; p<.001) and results were maintained at 9-month follow-up (MPT -67.3%±43.7 vs CG -19.3%±68.6; mean difference between groups 47.0% [95%CI 26.0-68.0]; p<.001). Greater improvements after MPT were also observed in all secondary outcomes compared to CG, both at post-treatment and at 9-month follow-up. Regarding impression of change, 94% of women in the MPT group reported improvement compared with 17% in the CG at 9-month follow-up (p<.001).

To our knowledge, this is the first study investigating whether women sustaining a LAM avulsion can benefit from MPT. Statistically significant and clinically highly meaningful changes were found in the MPT group, compared to the CG, for reducing UI episodes, improving pelvic floor disorders symptoms (incontinence, prolapse, anorectal symptoms) and for alleviating the associated impact of quality of life.

This study provides strong evidence that MPT effectively reduces UI, improves pelvic floor disorder symptoms, and enhances quality of life in women with LAM avulsion. These findings support MPT as the first-line treatment for this high-risk group.

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