Comparison of two scoring systems for diagnosing levator ani muscle damage

Levator defects are risk factors for pelvic organ prolapse (POP) and its recurrence. The most widely used scoring systems for severity of defects shown on magnetic resonance imaging (MRI) and perineal ultrasound (US) are not identical. The aim of this study was to investigate the differences between these classification systems with regard to levator defects on US and their clinical relevance for recurrence after prolapse surgery. Women with previous cystocele repair underwent transperineal 3D US. Levator defects were graded according to the scoring system described with regard to MRI (DeLancey et al.) and perineal US (Dietz et al.). The results were compared using the weighted kappa and receiver operating characteristic (ROC) curves (SPSS version 20.0). We assessed 152 women. On US classification, more defects were categorized as highest grade compared with MRI classification [n = 64 (42 %) vs. n = 41 (28 %), p <0.01]. The grades of levator defects on both scoring systems showed very good agreement, with a weighted kappa of 0.82 [95 % confidence interval (CI) 0.75-0.88). The predictive value of scoring systems for cystocele recurrence after prolapse surgery showed an area under the receiver operating curve (AUC) of 0.63 and 0.64, respectively. Comparison of the two scoring systems showed good agreement but was lowest for the highest-grade defects. There was no difference in predictive value between scoring systems for cystocele recurrence after prolapse surgery.