Erection Curvatures

Most people think that the penis should be completely straight when erect.  Although this is the most common “shape” of an erection, studies have found that this only occurs in only 55% of men.  That leaves 45% of men with some type of slight curvature in their erection – whether curved up, down, to the left, to the right, or a combination.  In addition, it’s not terribly uncommon for some men to notice a slight twisting of the penis during an erection. 

However, some men have curvatures of the penis that are significant.  In some cases, these abnormalities can lead to self-confidence issues when it comes to sexual activity and in some cases can cause pain.  In extreme cases it can make intercourse difficult or even impossible.  For some men, these curvatures can be a long-standing issue, even since puberty.  For others they can occur over time or after an injury to the penis.

CURVATURE CAUSES

There are three main causes of penile curvature.  The first occurs in boys with urethral misplacements – hypospadias and epispadias.  These types of curvatures are sometimes referred to as “chordee”.  These are usually discovered at birth and the surgical correction of the urethral abnormality typically resolves the penile curvature.  However, there are two types of curvature that affect adult men.  The first is called Congenital Penile Curvature or CPC.  This is a natural curve present since puberty.  This can affect as many as 4%-10% of men. [i]   The second is called Peyronie’s Disease or PD and is a new curvature during adulthood affecting 13% of men. [ii]    

 

Slight curvatures can occur during puberty as the penis grows and one side grows more quickly than the other.  By the end of puberty, the penis should be relatively straight.  However, a slight curvature when the penis is erect is fairly common and as just mentioned, occurs in nearly 45% of adult men[iii].  Significant curvatures that may warrant treatment are typically greater than 30 degrees.  In some men, these curvatures can be as much as 60 degrees to 90 degrees which can often interfere with sexual relations and can cause penile and sexual pain.

We will discuss curvatures in the following ways:

  • Types/causes of erection curvatures

  • Direction of erection curvatures

  • Twisting/Torsion of erection curvatures

CURVATURE TYPES

There are four main types of curvatures.

  • Peyronie’s Disease (PD) is caused by collagen (scar tissue formation) in the erectile tissues of the penis.   This scar tissue is called a plaque.  PD presents as a “new curvature” that wasn’t there before or a “worsening” of a slight curvature.  PD becomes more likely as a man ages.

  • Congenital Penile Curvature (CPC) is caused by differences in length or tightness of the three columns of erectile tissue.  This can occur during fetal development and be noticed at birth.  In these cases, surgical correction in infancy is usually performed.  However, CPC may occur or not be noticed until puberty when the penis does the majority of its growth.  CPC often requires an older teen or adult man to seek treatment independently since the curvature was not noticed by parents during infancy/childhood.  This can lead to a delay in treatment until sexual activity becomes problematic.

  • Tight Frenulum is a curvature at the neck of the penis caused by a tight frenulum that pulls the glans forward and downward during an erection.

  • Urethral chordees are caused by structural issues with the urethra in hypospadias and epispadias that often pull the penis into a bent position.  This is often noticed and corrected during infancy or childhood.

                          Onset             Curvature           Incidence[iv]           Direction

 

Peyronie’s         Adulthood       Curves at           Up to 13%            Usually

Disease            (often later)     one location        during lifetime      upward 

                                                                                                         (dorsal)

Congenital         During or        Along entire        0.6% with             Usually

Penile                after                shaft                   significant curve   downward

Curvature          puberty                                       (4-10% with         (ventral) or

(CPC)                                                                   slight curve)         to side

                                                                                                         (lateral)

Tight                  Youth (post-    Between glans    5% of                   Downward

Frenulum           retraction)       and shaft             uncircumcised     (ventral)

                                                                             men[v]

Urethral             Birth                 At point of           0.1%                    Downward

Chordee                                    urethral                                           (ventral)

                                                  stricture

PEYRONIE'S DISEASE

Peyronie’s disease (PD) presents as a new curvature in a penis that was previously straight.  It is the most common type of penile curvature.  In fact, some studies suggest that nearly 13% of men will have a PD type curvature at some point during their life.[vii]  The curvature in the penis will suddenly appear and often will get more severe before it gets better.  In many cases, the curvature will resolve on its own with time. 

PD is caused when fibrous tissue (often scar tissue) forms either in the erectile column or on the tunica.  This fibrous tissue is called a plaque.  The erectile tissue surrounding the plaque is unable to expand during an erection causing the penis to not become erect in the area thus creating a curvature.

shutterstock_258582335 PEYRONIES.jpg

If the plaque is located next to the tunica, the tunica is unable to stretch so the erectile tissue directly below it cannot engorge.  When the penis is either flaccid or erect, the plaque can often be felt under the skin of the penis where the curvature takes place.  In many cases, the curvature is abrupt, meaning the penis changes directions at the site of the plaque rather than curving consistently along the entire shaft.

Plaques are often caused by injuries to the erectile tissue.  This can occur due to a penile fracture or due to microfractures that may occur during intercourse.  Microfractures that occur during sexual activity are usually caused by the penis not being completely rigid.  As the penis moves back and forth during intercourse, lack of rigidity can cause small kinks to occur in non-rigid penile tissue causing small injuries.  As the body heals these microfractures, scar tissue is put down and this can create a plaque.  PD occurs more often as men age, one theory is that erectile dysfunction and less rigid erections that accompany advancing age may cause more of these microscopic injuries during intercourse.  PD is also more common in men that have connective tissue disorders like Dupuytren’s contractures (a disorder of the hands where the tendons become tight and cause the fingers to curl).  This is thought to occur due to these men being more likely to overproduce collegen.  Finally, although not well documented, stretching or traction of the penis for enlargement purposes can potentially cause tears which can be more susceptible to scaring and plaque formation; hence, another reason to avoid penis extenders and enhancement devices.

In the Acute Phase (within the first six to 18 months), the symptoms begin with pain in the penis, either when flaccid or when erect.  Inflammation at the site leads to the formation of a plaque.  When the plaque develops it can often be felt beneath the skin of the penis and curvatures may start bending around the plaque site.  As the injury heals, the pain may subside.  When the plaque has fully developed and stops growing, then it enters the Chronic Phase.[viii]  During this Chronic Phase, curvatures typically worsen in one-third to one-half of men or stay the same in one-half to two-thirds of men.  Spontaneous improvement is more uncommon and only seen in one-tenth of men with PD.[ix]

Treatment

 

Treatment for PD may include non-drug therapy, oral medications, injectable medications, or even surgery. 

 

Non-drug therapies include watching-and-waiting and two types of penis/plaque stretching.  Because PD curvatures are often caused by the healing processes of the body – watching and waiting is not uncommon.  However, as mentioned previously, spontaneous correction only occurs in about one-tenth of men (studies show complete resolution ranging from 3-13% or the time).  The other two non-drug therapies involve stretching the plaque and the penile tissues surrounding it.  The first stretching option involves the use of a penis pump to induce an erection (men with PD often have erectile dysfunction as the pain of a growing erection can often halt the erection process from proceeding to the rigid stage).  Using a vacuum causes engorgement of the erectile tissues to the rigid stage in an effort to help stretch and loosen the plaque.  However, these devices can be uncomfortable and if too much vacuum pressure is applied they can cause pain and reddening of the penis.  A review of clinical trials found that vacuum devices are fairly ineffective in the treatment of PD. [x]  The second type of stretching therapy is called Penile Traction Therapy (PTT) and involves penile extender devices to stretch the plaque.  Penile extenders consist of two rings (one goes on the base of the penis and the other at the neck of the penis) connected by two rods, one on each side (see image on this page[xi] ).  The rods are lengthened over time to cause stretching of the flaccid penis.  This stretching is thought to stretch and help decrease the inflexibility in the plaque, thus decreasing the angle of a curvature.  These devices are placed around the flaccid penis for a few hours each day and require consistent use.  Discomfort is the number one complaint, and spontaneous erections may be constricted by the rings and become painful, potentially causing penile strangulation.  A study found that these devices were only slightly effective, decreasing curvatures by just under 5 degrees.[xii]  Other trials have shown decreases of 10 to 45 degrees; although, these decreases were in men with early stage (acute) PD who have severe curvatures and the plaque may have been more susceptible to stretching in these earlier stages.[xiii]  It is best to have a healthcare provider guide the choice of whether or not a penis pump or extender is a valid treatment option and which products are reputable and can be recommended.

shutterstock_505690057.jpg

Many medication therapies have been studied, but few oral medications have shown significant impact on PD.  Oral medications that have shown some effectiveness include vitamin E, colchicine, potassium amino-benzoate, and carnitine.  However reductions in curvatures have only been seen in poorly controlled trials and well-controlled trials often show no significant effect on treating the curvature (namely that the curvature may have gotten better due to watching and waiting rather than from the oral medication).  Colchicine and potassium amino-benzoate both cause significant stomach side effects and most men stop taking them due to these side effects. 

Medications that are injected into the plaque show more positive effects.  These injectable medications include Verapamil, Interferon, and Collagenase.  The only medication approved in the U.S. for the treatment of PD is an intralesional drug (medication that is injected into the plaque lesion) called collagenase (Xiaflex®).  Collagenase works by “dissolving” the collagen in the plaque.  Treatment with collagenase begins in a urologist’s office then continues at home.  The medication is injected into the plaque, then the clinician stretches the penis to help break down the plaque.  The man continues penis stretching procedures at home to help break apart the fibers in the plaque.  Verapamil on the other hand is a blood pressure medication that is fairly inexpensive.  Verapamil has been shown to decrease the pain and curvature associated with PD.  The final injectable drug is Interferon.  This is significantly more costly than Veramapil, but some trials have shown that it can be effective.[xiv]

For men who don’t respond to watching and waiting nor to medication therapy, then surgery is an option to resolve the curvature and any associated pain.  Surgery can be performed to straighten the penis.  This is discussed in more depth below for CPC treatment.

 

CONGENITAL PENILE CURVATURE (CPC)

CPC is thought to be rare – affecting less than 1% of infant boys.[xv]  However, since CPC can develop during puberty when the penis enlarges, some suggest that when including slight curvatures (less than 30 degrees) that the rate could be as high as 4-10% of men who have a slight “natural” curve when the penis is erect.   However, more significant curvatures can be seen in about one out of nearly 200 men.

CPC is caused when one column of erectile tissue does not grow to be the same length as the other columns.  It can also be caused when one side of the tunica is less flexible than the tunica surrounding another erectile column of tissue.  This can be genetic and some studies have shown brothers with similar CPC curvatures during adulthood.[xvi]  These differences allow one column of erectile tissue to have a different maximum “fill” capacity.  When columns of erectile tissue are not proportional, the penis will curve either toward the “shorter” column or away from the “longer” column.  CPC is typically recognized either during or at the end of puberty.  The important thing here is that CPC is not a “new onset” – it just doesn’t appear.  It is how a man’s penis grew during puberty and the curve has been present his entire adult life.  During a medical examination, there are no plaques or hard lumps felt in the penile tissue that would explain the curvature – the tissue itself is normal.  In addition, most cases of CPC are not noticed on physical examination since they often don’t appear when the penis is flaccid, only when it is erect. 

Curvatures for CPC tend to be uniform (the bend is over the entire shaft of the penis rather than an abrupt bend around a single point along the shaft of the penis).  CPC curvatures can be in any direction, but tend to be more ventral (pointing downwards).  This is caused by an abnormality with the corpus spongiosum where the column is either too short or the tunica is too tight.  However, CPC can also be lateral (curving to the right or left) if the left and right cavernosa are not the same length or have the same tightness around the tunica.  Rarely will the curvature be dorsal or upwards.

Men with CPC can also have an accompanying penile torsion or rotation.  This occurs for a few reasons – one of which is that one longer cavernosa can rotate the penis as well as curve it.  In these men, the curvature may actually look somewhat like a corkscrew – most often bending downwards and rotating to the left.

 

Currently, surgery is the only treatment for CPC.  Medications and non-drug therapies are ineffective.  The surgery typically involves one of four methods. 

  • The first is called plication and involves the removal of a wedge of tissue from the longer side of the penis to allow the erectile tissues to become the same length.  If shortening of one side is performed during surgery the shortening of the penis that results usually doesn’t cause any issues.  Typically men with CPC have a penis that is longer than average – most often in the 90th percentile.  This often results in an erection length that is about ¾ of an inch longer than “average”.  Since surgery usually only shortens the penis by ½ to 1 inch, the resulting length of the erect penis is right around average.  Because of this, shortening of the penis during surgery rarely if ever causes problems with sexual activity.  In fact, even though the penis may be slightly shorter, sexually activity often improves dramatically due to the straightening of the penis. 

  • The second type of surgery is the opposite of the plication and is called a graft.  In this instance, an incision is made on the shorter side of the penis and a graft of tissue is inserted to lengthen the shorter side. 

  • The third method loosens the tunica on the smaller erectile column allowing it to expand and lengthen more. 

  • The fourth type of surgery is called the STAGE method.  Small incisions are made in the tunica on the longer side of the penis.  These incisions are then sutured together more tightly, thus tightening the tunica on the longer side which straightens the penis.  This final method does not decrease the length of the penis.

 

TIGHT FRENULUM

Some men notice a curvature between the tip of the penis and the shaft.  In adults, this is most often caused by a tight frenulum. 

 

Penis Frenular Curves.png

As a reminder, the frenulum is a small piece of tissue that connects the foreskin to the underside of the glans.  Most often, the frenulum stretches when the penis becomes erect without any problem.  This results in a 0° angle where the glans or tip of the penis is in line with the shaft (above left).  A short or tight frenulum is called frenulum breve.  This occurs in about 1 out of 20 uncircumcised men, [xvii] although some circumcised men can also have frenulum breve as well since the frenulum is not always fully removed during circumcision.  This short/tight frenulum pulls the glans of the penis downward during an erection.  This may be mild (such as the 30° seen second from the left), moderate (such as the 60° seen second from the right), or more severe (90° as shown to the right).

Frenulum breve can be painful during an erection as the frenulum pulls the glans or tip of the penis downwards (to see an example, click HERE).  In addition, the frenulum may get a “skin burn” or tear during sexual activity when the glands is forced upwards causing the stretched frenulum to have excessive friction. 

There are three main treatments for frenulum breve.

  • The first treatment is circumcision, removing the foreskin and tight frenulum. 

  • The second treatment is a frenulectomy.  A frenulectomy is a procedure that simply removes the tight frenulum rather than the entire foreskin.  

  • The third treatment is, cutting or tearing the frenulum and allowing it to heal on its own as seen below.  This can also resolve the issue.  Men who have torn the frenulum during sexual activity, may simply be allowed to heal on their own if the tear unhinged the tight frenulum.

URETHRAL CHORDEES

When the urethral meatus opens onto the penis in a place other than the tip of the glans (tip of the penis) – it is often caused by a shortening of the urethra and can affect the corpus spongiosum tissue surrounding the urethra.  This can lead to a curvature of the penis.  In these cases, this curvature is often called a “chordee”.  In the case of hypospadias, where the urethra is on the underside of the penis, this can cause the penis to curve downward.  On the other hand, in boys with epispadias, the urethra opens on the dorsal or top side of the penis and these boys will often have a curvature that bends upwards.

Most of these abnormalities are discovered at birth and are most often surgically corrected in infancy.  In men who have reached adulthood without surgical correction, surgery can correct these conditions, especially if they are presenting with problems of pain or difficulties with intercourse. 

CURVATURE DIRECTIONS

Curvatures can be in one of eight main directions – left, right, upward, downward, up & left, up & right, down & left, or down & right.  Angles less than 30 degrees are considered mild, 30-60 degrees are moderate, and above 60 degrees are severe.  Most of the 45% of men with curvatures have mild curvatures less than 30 degrees (most of these much less than 30 degrees and perhaps closer to 10 degrees or less).  These slight curvatures rarely cause pain or interfere with sexual activity so are typically not treated medically.  Men with moderate to severe curvatures may experience pain and difficulties with intercourse.  We will go through these different directions explaining what may be going on with the erectile columns to cause a curvature in that particular direction and outline in illustrations varying degrees of severity from mild to severe curvatures:

 

Left (lateral left)

In this curvature, the penis bends to the left with no curvature up or down.  In CPC, curvatures occur when the left cavernosa is either shorter or tighter than the right cavernosa.  Slight curvatures occur in 7-10% of men, but more severe curvatures are rare and occur in less than 1% of men.[xxx]    

In PD this is caused by a plaque on the left cavernosa and occurs in 28% of men with PD.  The image below shows varying degrees of left lateral curvature from the backside of the penis (top). 

[xxx] [1] Wespes E, et.al., Guidelines of Penile Curvature, European Association of Urology February 2012.

iStock-486934184 - left lateral.jpg

Right (lateral right)

 

In this curvature, the penis bends to the right with no curvature up or down.  In CPC, curvatures occur when the right cavernosa is either shorter or tighter than the left cavernosa.  Right lateral curvatures occur in only 1-2%. 

 

In PD this is caused by a place on the right cavernosa and occurs in only 10% of men with PD.  Varying degrees of right lateral curvatures are shown below.

iStock-486934184 - right lateral.jpg

Upward (dorsal)

In this curvature, the penis bends upwards/backwards.  It is the most common type of natural curvature occurring in 20-24% of men.  This often occurs when the spongiosum is slightly longer than the cavernosa.  This is fairly common in PD, occurring 30% of the time.  This occurs when a plaque develops on the upper shaft of the penis between the two cavernosa.  To see an example of a ventral Peyroine’s of 90° click HERE.  To see an example of ventral Peyroine's of 180°, click HERE.  This type of curvature is common in babies born with epispadias as the urethra abnormality pulls the penis tighter on the back side than the underside. 

Dorsal Curve - iStock 486934218.png

Downward (ventral)
 

In this curvature, the penis bends downwards.  This occurs in 5-11% of men and is often caused by the tunica around the spongiosum being too tight.  In men with PD, this type of curvature occurs 15% of the time.  This type of curvature is seen in the majority of CPC as well as in babies born with hypospadias as the urethra abnormality pulls the penis on the underside of the penis. .  To see an example of a 60 degree ventral curvature, click HERE.  To see an example of a 90 degree ventral curvature, click HERE.

Ventral Curve - iStock 486934218.png

Multi-directional curves

 

These curves occur when the penis curves both upward or downward and to one side.  In severe cases, this can cause the penis to rotate much like a corkscrew.  However, in other cases it can cause the penis to zig zag.  To see an example of a zig zag curvature, click HERE.

Up and to the side (dorsolateral) – in this curvature the penis not only bends upwards but to one side as well.  These men often have one cavernosa that is significantly shorter or tighter than the other cavernosa and the spongiosum. 

  • Up & left – occurs when then the penis curves upwards and to the left.  This occurs in 1-3% of men.  In this case the left cavernosa is often shorter/tighter. 

  • Up & right – occurs when the penis curves upwards and to the right.  This rarely occurs, only affecting <0.1% of men.  In this case, the right cavernosa is often shorter/tighter.  

  • In men with PD this occurs when a plaque is located on the upper side of the penis shaft and occurs in 12% of men with PD and can be either right or left.

 

Down and to the side (ventrolateral) – in this curvature the penis bends not only downwards but to the side as well.  This is typically caused by one cavernosa being significantly longer/looser than the other two erectile columns. 

  • Down & Left –  occurs when penis curves downwards as well as to the left.  This occurs in 0.1-4% of men.  In this case, the right cavernosa is the longer/looser column. 

  • Down & Right – occurs when the penis curves downwards and to the right.  This type of curvature has not been observed in clinical trials, but could occur in theory.

  • In men with PD, this type of curvature is caused by a plaque between one of the cavernosa and the spongiosum.  This is the least seen curvature in men with PD, occurring only 5% of the time.[xix]


[i] ScientificWorldJournal. 2011 Jul 28;11:1470-8. doi: 10.1100/tsw.2011.136. Abnormalities of penile curvature: chordee and penile torsion. Montag S1, Palmer LS.

[ii] PLoS One. 2016; 11(2): e0150157. Published online 2016 Feb 23. doi: 10.1371/journal.pone.0150157 PMCID: PMC4764365 PMID: 26907743

The Prevalence of Peyronie's Disease in the United States: A Population-Based Study Mark Stuntz,1,* Anna Perlaky,1 Franka des Vignes,2 Tassos Kyriakides,3 and Dan Glass1

[iii] Sparling J (1997) Penile Erections: Shape, angle, and length, Journal of Sex & Marital Therapy, 23:3, 195-207.

[iv] https://www.ncbi.nlm.nih.gov/pubmed/27103093 (12/10/16)

[v] Arora B, A simply technique of frenuloplasty for penile frenulum breve, International Journal of Science Research. 5(2); Feb 2016, 289-291.

[vi] https://my.clevelandclinic.org/health/diseases/15454-penile-torsion

[vii] PLoS One. 2016; 11(2): e0150157. Published online 2016 Feb 23. doi: 10.1371/journal.pone.0150157 PMCID: PMC4764365 PMID: 26907743

The Prevalence of Peyronie's Disease in the United States: A Population-Based Study Mark Stuntz,1,* Anna Perlaky,1 Franka des Vignes,2 Tassos Kyriakides,3 and Dan Glass1

[viii] https://my.clevelandclinic.org/health/articles/peyronies-disease-urological-overview (12/28/18)

[ix]  http://uroweb.org/wp-content/uploads/16-PenileCurvature_LR.pdf (12/28/18)

[x] Ther Adv Urol. 2013 Feb; 5(1): 59–65. doi: 10.1177/1756287212454932 PMCID: PMC3547530 PMID: 23372611 Penile traction therapy and Peyronie’s disease: a state of art review of the current literature Eric Chung  and Gerald Brock

[xi] 

[xii] J Sex Med. 2009 Feb;6(2):558-66. doi: 10.1111/j.1743-6109.2008.01108.x. Epub 2008 Dec 2. Use of penile extender device in the treatment of penile curvature as a result of Peyronie's disease. Results of a phase II prospective study. Gontero P1, Di Marco MGiubilei GBartoletti RPappagallo GTizzani AMondaini N[xiii] Ther Adv Urol. 2013 Feb; 5(1): 59–65. doi: 10.1177/1756287212454932 PMCID: PMC3547530 PMID: 23372611 Penile traction therapy and Peyronie’s disease: a state of art review of the current literature Eric Chung  and Gerald Brock

[xiv] http://www.urologyhealth.org/urologic-conditions/peyronies-disease/treatment (1/12/19)

[xv] The Journal of Urology Volume 150, Issue 5, Part 1, November 1993, Pages 1478-1479 The Incidence of Congenital Penile Curvature

Author links open overlay panelDanielYachiaMordehayBeyarI. AtillaAridoganShimonDascalu 

[xvi] Cent European J Urol. 2013; 66(2): 217–220.Published online 2013 Aug 13. doi: 10.5173/ceju.2013.02.art27 PMCID: PMC3936146 PMID: 24579033 Familial appearance of congenital penile curvature – case history of two brothers Wojciech Zachalski, 1 Marcin atuszewski,1 Kazimierz Krajka,1 and Krzysztof Rębała2

[xvii] Arora B, A simply technique of frenuloplasty for penile frenulum breve, International Journal of Science Research. 5(2); Feb 2016, 289-291.

[xix] Journal of Andrology, Vol. 32, No. 5, September/October 2011 Factors Affecting the Degree of Penile Deformity in Peyronie Disease: An Analysis of 1001 Patients ATES KADIOGLU,* ONER SANLI,* TOLGA AKMAN,{ ONDER CANGUVEN,{ MEMDUH AYDIN,§ FATIH AKBULUT,* AND FARUK KUCUKDURMAZ*  https://onlinelibrary.wiley.com/doi/pdf/10.2164/jandrol.110.011031 (12/28/18)

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