Impact of Camera Deviation on Penile Curvature Assessment Using 2D Pictures

Pediatric urologists' confidence and accuracy in estimating penile curvature

BACKGROUND

Assessment and management of congenital penile curvature (PC) can be variable. Methods for correction of PC usually are dependent on degree of PC which is reliant on how degree is assessed. We sought to assess the confidence and accuracy of measuring PC and hence management using case-based examples.

METHODS

A survey was emailed to members of the Societies for Pediatric Urology. Demographic information, management strategies for PC, and self-reported confidence in measuring PC were assessed. A Likert scale measured self-confidence. Case scenarios were used to assess ability to measure PC and methods of correction. The cases consisted of three computer-generated penis model images with arc-type ventral curvature and one image of lateral curvature in an infant.

RESULTS

The response rate was 30% (108/355). The mean confidence score was 3.6 ± 0.8 (3-fairly confident; 4-very confident). In clinic, 89% of urologists used eyeball estimates to assess PC; 5% used both eyeball and goniometer. In the operating room, 71% used eyeball estimates, 8% used goniometer, and 16% used both. If sole decision-maker, urologists recommend surgical correction of PC over observation at median 30° (IQR 21-30°). At a median of 45°, there was a shift in corrective surgical preference from dorsal plication (DP) (IQR 30-54°) to ventral lengthening (IQR 34-60°). Urologists underestimated PC degree for all cases (summary table). For all cases, there was no association between years in practice or confidence level on estimated PC degree. In case 1, only 24% of urologists would correct a mean estimate of 23° PC; those who would correct had a higher mean PC estimate vs those who would not (28° vs 21°, p < 0.001). Case 2 and 4 had similar estimations and correction methods. In case 2, those who chose VL had a higher mean PC estimate vs those who did not (43° vs 37°, p < 0.01), but no estimate difference was seen for DP (p = 0.52). In case 4 with lateral PC, those who chose DP had a higher mean PC estimate vs those who did not (41° vs 33°, p = 0.049). Yet in case 3, there was no difference in PC estimate in urologists who chose VL vs not (57° vs 53°, p = 0.16).

CONCLUSIONS

A uniform underestimation of PC existed despite self-reported confidence in the ability to measure PC. An increasing willingness to perform surgical correction was demonstrated with a shift towards VL for ventral curvature and less so for lateral curvature as PC worsens.

How accurate is eyeball measurement of curvature? A tool for hypospadias surgery

INTRODUCTION

Correction of penile curvature or "chordee" is a major component in the management of hypospadias. Accurate assessment and management of penile curvature influence both short- and long-term outcomes of surgery.

AIM OF THE STUDY

The objective of this study is to investigate the accuracy of eyeball measurement and how does it compare to objective measurement by standard goniometry (SG) and smartphone app goniometry (AG).

MATERIALS AND METHODS

A Dropbox file request link was shared with paediatric urologists on various social media platforms requesting participants to upload a picture of their index finger showing what they thought 30 degrees of curvature look like using their proximal inter phalangeal joint as the point of maximal curvature., The images were assessed using SG to measure the angle of curvature. The images were also assessed using AG by the principal investigator, a physician, a scrub nurse and a paediatric urology consultant., Statistical analysis was performed using SPSS statistics software version 26 (Armonk, NY: IBM Corp). A one sample t-test and a one-way chi squared test were used to evaluate significant frequency differences. Pearson correlation was used to compare AG measurements to test intra- and inter-observer reliability and to compare AG measurements vs SG measurements. Assuming 5-degree variability in goniometer measurements and 2-degree difference between the sample and population, the number of participants needed was calculated to be 49.

RESULTS

Fifty-two responses were received.32.7% of respondents simulated 30° accurately (17/52). A significant proportion (23/52, 44.2%) overrepresented the degree of curvature and 23.1% (12/52) underrepresented it (p = 0.01). Compared with objective measures, eyeball estimates differed by an average of 10° ± 1.5 SE. Measurements obtained by AG were comparable to measures obtained by SG and showed excellent intra-observer and inter-observer correlation (R = 0.983, P < 0.001).

DISCUSSION

We demonstrated a significant discrepancy between eyeball assessment of curvature and objective measurements in a cohort of hypospadiologists. This can be very relevant to intraoperative decision making. The limitation of the study is the use of a simulated model rather than assessment of curvature in patients with hypospadias. Another limitation is the lack of standardization of the way the pictures were taken.

CONCLUSION

We demonstrated a tendency among hypospadiologists to overestimate or underestimate curvature by an average of 10° on eyeball assessment. The use of App Goniometry shows excellent interobserver reliability and is comparable to standard goniometry in curvature assessment.

Plate Objective Scoring Tool: A new preoperative indicator of penile curvature degree in children with distal hypospadias

OBJECTIVES

There is an unmet need for preoperative methods that surgeons can use to objectively quantify hypospadias anatomic variables and determine risk of penile curvature. We, therefore, assessed whether Plate Objective Scoring Tool measurements were correlated with degree of ventral curvature in affected children.

METHODS

Patients undergoing distal hypospadias repair were enrolled into the study between January 2018 and December 2020 and were categorized independently by at least two surgeons using Plate Objective Scoring Tool. Scores were compared statistically to determine the degree of ventral curvature and requirement for correction.

RESULTS

Sixty-five patients with a median age of 18 months (interquartile range 13-26) were enrolled into the study prior to surgery for primary distal hypospadias. Patient probability of significant postoperative curvature (>20°) was determined with moderate confidence using a cutoff Plate Objective Scoring Tool score of 1 (sensitivity 75%, specificity 60%). Presurgery Plate Objective Scoring Tool scores were negatively correlated with subsequent degree of curvature (r = -0.37, P = 0.003), with values <1.0 predicting >20° curvature.

CONCLUSIONS

Plate Objective Scoring Tool scoring offers a succinct method of describing hypospadias severity and correlates well with postoperative outcomes. The Plate Objective Scoring Tool system can therefore be used to objectively predict the likelihood of penile curvature and aid communication between surgeons and researchers, as well as improving parental counseling.

Surgical management of primary severe hypospadias in children: an update focusing on penile curvature

Over the past two decades, assessment and treatment of associated curvature has emerged as a major issue in treating patients with proximal hypospadias. However, the cut-off for defining a curvature as clinically significant is still unclear, as not all patients are bothered by the same degree of curvature and, although the need for a method to assess the curvature objectively has been emphasized, no standard method yet exists. Curvature is multifactorial. The same degree of curvature can be due to any possible combination of skin and/or subcutaneous dartos tethering, a short urethral plate and an intrinsic corpora disproportion. Different strategies can be used to treat curvature, depending on the underlying cause, surgeon preferences, and the goals of the repair. In the past 10 years, use of urethral plate transection and ventral lengthening procedures has increased, although the lack of long-term follow-up data on ventral lengthening procedures suggests that the use of such procedures should be selective. Furthermore, straightening manoeuvres are influenced by the technique used for subsequent urethroplasty and, in turn, may influence the success rate of the urethroplasty. This Review provides a comprehensive overview of the major developments from the past 10 years in the management of severe proximal hypospadias in children.

3D-printed phantoms to quantify accuracy and variability of goniometric and volumetric assessment of Peyronie's disease deformities

Characterization of Peyronie's disease (PD) involves manual goniometry and penile length measurement. These techniques neglect volume loss or hourglass deformities. Inter-provider variability complicates accuracy. Using 3D-printed models, we aimed to evaluate measurement accuracy and variability and establish computational assessment workflows. Five digital phantoms were created: 13.0 cm cylinder, 13.0 cm hourglass cylinder, 15.0 cm cylinder with 40° angulation, 12.0 cm straight penis, and 12.9 cm PD penis with 68° angulation and hourglass. Lengths, volumes, and angles were determined computationally. Each phantom was 3D-printed. Ten urology providers determined lengths, angles, and volumes with measuring tape, goniometer, and volume calculator. Provider versus computational measurements were compared to determine accuracy using t-tests or Wilcoxon rank-sum tests. No significant differences were observed between manual assessment of length of penile models and designed length in penile models. Average curvature angles from providers for bent cylinder and PD phantoms were 38.3° ± 3.9° (p = 0.25) and 57.5° ± 7.2° (p = 0.006), respectively. When assessing for volume, hourglass cylinder and bent cylinder showed significant differences between designed volume and provider averages. All assessments of length, angle, and volume showed significant provider variability. Our results suggest manual measurements suffer from inaccuracy and variability. Computational workflows are useful for improved accuracy and volume assessment.

Standardization of penile angle estimation with a semi-automated algorithm

INTRODUCTION

Penile curvature (PC) refers to an abnormal bending of the main longitudinal axis of the penis. It is frequently associated to hypospadias. To date, accurate and objective evaluation of PC is not easily reproducible amongst surgeons and there are no stablished protocols on how to measure PC in a standard way and in real-time to guide intraoperative decision making. For this reason, we want to present the results of creating a semi-automated algorithm to establish a reproducible and objective assessment of PC and propose it as a standard protocol for clinical applicability using inanimate 3-D penile models.

METHODS

This project consisted in two different phases. 1. Creation of an automated algorithm to estimate penile angle based on digital images. 2 Use of the algorithm to estimate penile angle on 3-D models and estimate interrater agreement using the algorithm. The algorithm was created to initially identify the geometrical centerline of the penile model to establish an automated output for angle estimation. 3-D printed penile models with known curvature angles ranging from 10 to 90° were used to test the algorithm (total of 9 penile models. These models were curved at one hinge as opposed to an arc type model. For each inanimate model, a set of 5 pictures were obtained from a lateral view at different camera angles (0⁰, 15⁰, 30⁰, 45⁰ and 60⁰) at a standard distance of 75 cm. Angle estimation using our designed PC algorithm was performed by a total of 10 different evaluators. Inter-rater reliability analysis in using the semiautomated algorithm was performed using the inter-class correlation coefficient (ICC) with two-way mixed effect model.

RESULTS

If the camera angle was greater than 30°, the absolute angle mean difference was greater than 10°. Camera angle with the smallest mean difference was at 0⁰ with a mean difference of 7.83°. Agreement between raters showed greater variability towards the higher camera angles. Nonetheless, a high degree of between evaluator reliability was found between the measurements at different camera angles. Single measures ICC ranges from .873 to .946, p-values were all <.0001.

CONCLUSION

Our results help standardize PC assessment using digital images and reduce subjectivity using an algorithm for PC estimation. Optimal camera position between 0⁰ to 30⁰ vertical from the penis gives the least variable and most accurate angle estimation. Future studies using algorithms will help define predictive PC cutoff values and evaluate postoperative outcomes.

Peyronie's disease: Contemporary evaluation and management

Peyronie's disease is a common yet poorly understood condition characterized by penile pain, curvature, sexual dysfunction and psychological bother. Peyronie's disease represents a penile wound healing disorder, and is thought to arise from exuberant scarring in response to penile trauma in genetically predisposed men. In the absence of active treatment, the majority of men experience stable or worsening symptoms, with few reporting spontaneous resolution in penile curvature or other deformity. In contrast, penile pain improves or resolves in the majority of men. Treatment options vary based on symptom severity and stability. Several oral therapies are commonly prescribed, although to date there are no strong data to support any oral agents as monotherapy for Peyronie's disease. Other options including penile traction therapy and intralesional injections result in modest improvements for many patients, particularly when used early after symptom onset. Penile straightening through approaches, such as penile plication and plaque incision or partial excision and grafting, represent the most rapid and reliable approach to correct penile curvature once the symptoms have stabilized. Side-effects vary based on the type of surgery carried out, and include penile shortening, sensation changes and erectile dysfunction in the minority of men. In patients with drug refractory erectile dysfunction and Peyronie's disease, placement of a penile prosthesis will address both issues, and is associated with high levels of patient satisfaction. The current review provides a practical approach to the modern evaluation and management of patients presenting with Peyronie's disease.