## What is the transverse diameter of the pelvic outlet?

The transverse diameter of the pelvic inlet measures 13.5 cm. Midpelvis: The midpelvis is the distance between the bony points of ischial spines, and it typically exceeds 12 cm. Pelvic outlet: The pelvic outlet is the distance between the ischial tuberosities and the pubic arch. It usually exceeds 10 cm.

**What are the 3 diameters of the pelvic outlet?**

Antero – posterior diameters: Anatomical antero-posterior diameter =11cm. from the tip of the coccyx to the lower border of symphysis pubis. Obstetric antero-posterior diameter = 13 cm.

**How do you measure the transverse diameter of an outlet?**

The transverse diameter of the outlet is assessed clinically by measuring the distance between the ischial tuberosities along a plane passing across the anus;• The anteroposterior outlet diameter is measured from the pubis to the sacrococcygeal joint.

### What are the dimensions of the true pelvis?

Measurements

Measurement | From | Length |
---|---|---|

Transverse diameter (of inlet) | Between extreme lateral points of pelvic inlet | 13.5–14 cm |

Oblique diameter I | Right sacroiliac joint | 12-12.5 cm |

Oblique diameter II | Left sacroiliac joint | 11.5–12 cm |

Anatomical conjugate (true conjugate) | Pubic symphysis | ~12 cm |

**What is transverse diameter?**

Transverse diameter – Diameter transversa The transverse diameter is the greatest diameter of cranial opening of pelvis (pelvic inlet).

**What is pelvic outlet?**

The pelvic outlet also called the inferior pelvic aperture, defines the lower margin of the lesser (true) pelvis. The pelvic outlet is the inferior opening of the pelvis that is bounded by coccyx, the ischial tuberosities, and the pubis symphysis.

#### How do you measure the transverse diameter of the pelvic inlet?

Diameters of the Pelvic Inlet The anteroposterior (or “conjugate”) diameter is the distance between the pubic symphysis and the sacral promontory. Three distances are: The anatomical conjugate or true: Measured between the sacral promontory and the upper edge of the pubic symphysis and measures an average of 11.0 cm.

**What is the landmark in the pelvic outlet?**

3 The pelvic outlet. The pelvic outlet is formed by the lower border of the pubic bones at the front, and the lower border of the sacrum at the back. The ischial spines point into this space on both sides.

**What is normal AP diameter?**

The anteroposterior (AP) diameter of the normal adult male cervical canal has a mean value of 17-18 mm at vertebral levels C3-5. The lower cervical canal measures 12-14 mm. An adult male without spinal stenosis has a diameter of 16-17 mm in the upper and middle cervical levels.

## What is anteroposterior diameter?

The anteroposterior (or “conjugate”) diameter is the distance between the pubic symphysis and the sacral promontory.

**How is a pelvic outlet formed?**

The pelvic outlet is formed by the ischiopubic rami, ischial spines, inferior symphysis pubis, sacrospinous ligaments, and coccyx. Axial oblique T2WI MR at the same level shows the coccygeus muscle. It arises from the tip of the ischial spine, and the fibers fan out and insert into the lateral side of the coccyx.

**Where is the pelvic inlet and outlet?**

The pelvic outlet is the inferior opening of the pelvis that is bounded by coccyx, the ischial tuberosities, and the pubis symphysis.

### What are the dimensions of the pelvic outlet?

Diameters of pelvic outlet Antero – posterior diameters: Anatomical antero-posterior diameter =11cm from the tip of the coccyx to the lower border of symphysis pubis. Transverse diameters: Bituberous diameter = 11 cm between the inner aspects of the ischial tuberosities.

**Which is the smallest transverse diameter in the pelvis?**

Bispinous diameter is the smallest transverse diameter (10.5 cm). 1. Plane of pelvic inlet: Makes an angle of inclination of 55 degrees with horizontal 2. Plane of least pelvic dimension (obstetric outlet): Lower border pubic symphysis – Ischial spines – Tip of sacrum

**How big is the pelvic cavity in centimeters?**

Pelvic cavity is almost round with both AP and transverse diameter 12 cm. Both the oblique diameters of inlet and pelvic cavity are 12 cm. AP diameter – 11, 12, 13 from up to down Transverse diameter: 13, 12, 11 from up to down

#### How big is the obstetric conjugate in the pelvis?

Obstetric conjugate cannot be measured clinically but can be estimated by: Diagonal conjugate – 2.5 cm Bispinous diameter is the smallest transverse diameter (10.5 cm). 1. Plane of pelvic inlet: Makes an angle of inclination of 55 degrees with horizontal