Levator defects can be detected by 2D translabial ultrasound

Childbirth-related morphological abnormalities or defects of the puborectalis muscle ("avulsion") can be diagnosed by magnetic resonance imaging and three-dimensional (3D) ultrasound, but neither method is universally available. In this study, we tested validity and reproducibility of a new method for diagnosing levator avulsion by 2D translabial ultrasound.

Seventy-five women were examined for major morphological abnormalities of the puborectalis muscle by palpation, 2D and 3D ultrasound (US). For 2D US, we used an oblique parasagittal translabial approach. The operator using 2D US was blinded against all other findings.

Agreement between observers for diagnosis of avulsion by 2D US was 87% (Cohen's kappa 0.56, CI 0.33-0.80). Agreement between tomographic 3D US and 2D US was 87% (kappa 0.61, CI 0.45-0.77).

Defects of the puborectalis muscle can be diagnosed with 2D US. The finding of a discontinuity between the hyperechogenic muscle and the pelvic sidewall is moderately reproducible and agrees moderately well with palpation and 3D US.