What is the medical term for loss of curvature of the penis?

Loss of Penile Curvature in Peyronie's Disease

The medical term for loss of curvature of the penis is "penile retraction," which is a feature of Peyronie's disease when the normal curvature is lost due to fibrosis of the tunica albuginea. 1, 2

Understanding Peyronie's Disease

Peyronie's disease is defined as an acquired penile abnormality characterized by fibrosis of the tunica albuginea, which may be accompanied by:

• Pain
• Deformity (including loss of normal curvature)
• Erectile dysfunction
• Psychological distress 1

The condition occurs when normal elastic tissue of the tunica albuginea is replaced by scar tissue, which is not elastic and doesn't stretch during erection. This leads to various penile deformities, including:

• Abnormal curvature (most common)
• Loss of normal curvature
• Penile shortening
• Hourglass deformity 3

Pathophysiology of Penile Retraction

The development of penile retraction in Peyronie's disease typically follows this process:

1. Microvascular trauma to the penile shaft (often during sexual activity)
2. Inflammatory cascade with extravascular protein deposition
3. Fibrin trapping and cytokine overexpression
4. Changes in tunical collagen from type 1 to predominantly type 3
5. Formation of inelastic scar tissue that prevents normal expansion 1

Clinical Phases and Progression

Peyronie's disease progresses through two distinct phases:

1. Active phase: Characterized by changing symptoms, pain, and evolving deformity
2. Stable phase: When symptoms have been present for 12-18 months without changes 2

During these phases, the normal curvature of the penis may be lost due to the development of plaques and scarring in the tunica albuginea.

Assessment of Penile Deformity

Accurate measurement of penile deformity is essential for diagnosis and treatment planning:

• Intracavernosal injection (ICI) is considered the gold standard for measuring penile curvature 4
• Alternative methods include vacuum erection device (VED) and at-home photography, though these tend to underestimate the degree of curvature 4
• Patient self-estimates of curvature are often inaccurate, with a tendency to overestimate the actual degree of curvature by an average of 20 degrees 5

Impact on Sexual Function

The severity of penile deformity significantly impacts sexual function:

• Curvature greater than 60° is a robust independent predictor of sexual disability 6
• Approximately one-third of men with Peyronie's disease experience painful erections 7
• A percentage of men with Peyronie's disease develop erectile dysfunction 7

Treatment Considerations

Treatment options depend on the phase of disease and severity of symptoms:

• Conservative therapy is recommended during the active phase
• More invasive treatments are reserved for the stable phase
• Surgical interventions may include tunical plication, plaque incision/excision with grafting, or penile prosthesis implantation 3

Important Clinical Pitfalls

• Misdiagnosis: Penile retraction may be misdiagnosed if proper examination techniques are not used
• Undertreatment: The condition is often underdiagnosed and undertreated 3
• Premature intervention: Definitive treatments should be delayed until the disease has stabilized (12-18 months) 2
• Psychological impact: The condition can cause significant psychological distress requiring appropriate counseling 2

In clinical practice, it's crucial to perform a thorough examination of the genitalia, including assessment of testicular size, shaft fibrosis, and foreskin retractability, as recommended by clinical guidelines 2.