Pelvis and Perineum > Topographic Anatomy > Facts and Hints
FACTS & HINTS
PART A: HIGH-YIELD FACTS
Box 5-1-1: Clinical Points
Pregnancy: In pregnancy the placenta can be palpated above the pubic symphysis at 12 weeks, at the umbilicus at 12 weeks, and at the xiphisternum at 40 weeks.
Acute Urinary Retention: The bladder, if distended, may be palpated and percussed up to the umbilicus. On examination, the bladder is dull to percussion and in acute urinary retention, the patient may also complain of tenderness on palpation in the suprapubic region.
Supracristal Line: A useful landmark when performing a lumbar puncture since it corresponds to the 4th lumbar vertebral body. Lumbar puncture in adults is performed lateral decubitus position in the L4–L5 interspace.
Pilonidal Sinus: A blind ending hair-filled tract most commonly found in the midline of the natal cleft overlying the lower sacrum and coccyx and occurs in 26/1000 persons in the United States. The sinus can become infected, creating a so-called pilonidal abscess that usually requires drainage and/or excision of the sinus.