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Puboprostaticus muscle

The puboprostaticus muscle is a specialized band of fibers belonging to the levator ani muscle group in males. It extends from the posterior surface of the pubis toward the prostate, blending with its fibrous capsule and fascia. This muscle provides support to the prostate and bladder neck and is the male anatomical equivalent of the pubovaginalis muscle in females. It is important in maintaining continence and stabilizing pelvic organs.

Synonyms

  • Puboprostatic portion of levator ani

  • Puboprostatic ligamentous muscle fibers

  • Male homolog of pubovaginalis muscle

Location and Attachments

  • Origin: Posterior surface of the body of the pubis, adjacent to the pubic symphysis

  • Course: Fibers pass posteroinferiorly around the prostate, forming a supportive sling

  • Insertion: Blend with the prostatic capsule, fascia of the prostate, and fascia of the bladder neck

Relations

  • Anteriorly: Pubic symphysis and retropubic (Retzius) space

  • Posteriorly: Prostate gland and prostatic urethra

  • Superiorly: Bladder neck and internal urethral sphincter

  • Inferiorly: External urethral sphincter and perineal membrane

Function

  • Provides support for the prostate gland and bladder neck

  • Helps maintain urinary continence by stabilizing the urethra

  • Contributes to pelvic floor support as part of levator ani

  • Acts as a dynamic stabilizer during increases in intra-abdominal pressure (e.g., coughing, lifting, straining)

Clinical Significance

  • Important landmark during prostatectomy and pelvic surgeries

  • Weakness or damage may contribute to post-prostatectomy incontinence

  • Can be involved in pelvic floor dysfunction or trauma

  • Its female counterpart is the pubovaginalis muscle

MRI Appearance

T1-weighted images:

  • Muscle shows low-to-intermediate signal intensity

  • Fat in retropubic space appears bright, outlining the fibers

  • No fluid: ligamentous band difficult to distinguish from adjacent muscle

T2-weighted images:

  • Muscle demonstrates low-to-intermediate signal intensity

  • Fluid collections or inflammation adjacent to it appear bright

  • Fat maintains intermediate-to-bright signal contrast

STIR (Short Tau Inversion Recovery):

  • Normal muscle shows low-to-intermediate signal

  • Inflammation, strain, or edema shows bright hyperintensity

  • Fat is suppressed and appears dark

T1 Fat-Sat Post-Contrast:

  • Normal muscle enhances mildly and uniformly

  • Pathological involvement (post-surgical inflammation, infection, tumor infiltration) shows focal or irregular enhancement

  • Fat is suppressed and appears dark

CT Appearance

Non-Contrast CT:

  • Appears as a thin soft tissue density band between pubis and prostate

  • Fat in the retropubic space appears as low attenuation, providing contrast

  • Difficult to delineate without pathology

Post-Contrast CT:

  • Normal muscle shows mild uniform enhancement

  • Pathological changes (inflammation, tumor spread, post-surgical changes) appear as irregular thickening or nodularity with enhancement

  • Fat planes may appear obscured with inflammation or tumor infiltration

MRI image

Puboprostaticus muscle MRI axial anatomy image-img-00000-00000