Objective assessment of penile curvature in hypospadias: A narrative review

Hypospadias-associated ventral curvature (VC) exerts a critical influence on surgical decision-making and repair outcomes. Despite the clinical significance of VC, assessment is frequently performed by unaided visual inspection (UVI) which is prone to error. Alternative objective measurement techniques have therefore been proposed, including goniometry, smartphone applications, and artificial intelligence (AI)-based tools.

This review aims to evaluate the various techniques available for VC measurement in hypospadias surgery, focusing on their accuracy, reliability, and clinical utility.

A comprehensive literature search was conducted using PubMed, MEDLINE, and the Cochrane Database, covering publications from 1994 to 2024. Included studies assessed VC measurement techniques, including UVI, standard goniometry, smartphone-based goniometry, and AI-based tools. Risk of bias was determined using the Robvis tool.

Of 501 studies identified, 13 met the inclusion criteria. Findings revealed that UVI was associated with significant inaccuracy, leading to misclassification of VC severity and potential errors in surgical planning. Standard goniometry, while objective, was cumbersome in pediatric patients due to parallax errors and anatomical constraints. Smartphone-based goniometry provided improved accuracy and interobserver reliability. AI-based methods demonstrated the highest precision by minimizing subjectivity and enhancing standardization.

Objective measurement techniques, particularly smartphone-based and AI-driven approaches, are superior to UVI in assessing penile curvature in hypospadias. Future advances in AI technology and digital imaging may further refine VC assessment, leading to improved surgical outcomes. Adoption of standardized, objective measurement methods should be encouraged in clinical practice.