Levator ani muscle avulsion: Digital palpation versus tomographic ultrasound imaging.

Objective: To determine the diagnostic performance of digital palpation of levator ani muscle (LAM) avulsion compared with translabial tomographic ultrasound imaging (TUI).

Methods: A cross-sectional study, incorporating 195 women involved in a longitudinal cohort study. Palpation for levator integrity was performed, followed by a four-dimensional translabial ultrasound. LAM avulsion defects were diagnosed in the presence of puborectalis muscle detachment from its insertion. Post-processing analysis of ultrasound volumes for LAM integrity on TUI was performed blinded against palpation findings. Agreement between methods was assessed using Cohen's κ.

Results: In all, 388 paired assessments of LAM bilaterally, were available. Sixteen (8.2%) unilateral avulsion defects were detected on palpation. Sonographically, 31 (16%) were diagnosed with avulsions: 4.6% bilateral and 11.3% unilateral. An overall agreement of 91% was observed between digital palpation and TUI, yielding a Cohen's κ of 0.32 (95% confidence interval 0.15-0.48) demonstrating "fair agreement": and implying 25% sensitivity, 98% specificity, 63% positive predictive value, and 92% negative predictive value. Analysis of the first and last 20 palpations showed no change in performance during the 13-day study period.

Conclusion: Assessment of LAM avulsion defects by digital palpation is feasible but may require substantial training. Confirmation by imaging is crucial, especially if the diagnosis of avulsion may influence clinical management.