Predictors of hinge effect in patients with Peyronie's disease

Background Patients with Peyronie's disease present with a variety of penile deformities. Those with hinge effect can experience bothersome buckling of the erection and instability during penetrative sex; however, the actual characteristics and clinical implications are not fully understood. Aim To determine the factors that cause hinge effect and to assess the role on surgical intervention. Methods This retrospective review included 1223 consecutive patients who were examined by a single surgeon and had a complete penile duplex evaluation with curvature and hinge assessment. Baseline demographics, penile duplex findings, and clinical outcomes were used to assess for predictors of hinge effect. Outcomes Analyses were performed to assess preoperative predictors of hinge effect and surgical intervention. Results Hinge effect was observed at the time of penile duplex Doppler examination in 33% of patients. Circumferential girth discrepancy at point of indentation (odds ratio [OR] 1.82; P < .001), rigidity of erection (OR, 0.82; P = .002), and degree of primary curvature (OR, 1.03; P < .001) predicted the presence of hinge effect. When controlling for rigidity, a girth discrepancy >1 cm did appear to be associated with a hinge. Clinical Implications Circumferential girth discrepancy >1 cm, regardless of erectile rigidity, can be associated with hinge effect. Strengths and Limitations As a strength, this study included the largest cohort of patients with Peyronie's disease, all of whom were examined in a rigorous and uniform manner via the same operative counseling. However, the study is limited by its retrospective nature and potential for selection and observer bias, given that the treating physician was also assessing all penile deformities as well as performing operative intervention. Conclusions The presence of hinge effect can cause instability of erections during penetrative sex. Multiple factors may predispose patients to a hinge effect, including the quality of erection and severity of curvature. But when controlling for rigidity, a girth discrepancy >1 cm did appear to be associated with a hinge. While many factors, such as baseline erectile dysfunction and severity of curvature, are important in determining the optimal surgical intervention, assessing for preoperative hinge effect also influenced the surgical approach.