PRONE  -  Jack Knife

view from above

view from side
While prone, the patient is bent from the hips so that both the thorax and thighs are lower than the hips to facilitate access to the perianal, sacral, perineal, and lower alimentary canal areas.

Used for:

  • Procedures of the occipital or postero-lateral cranium
  • Sacral, perianal & perineal procedures

Preparation of the table


  1. The patient is induced on the transport cart, which is positioned next to the OR table.

  2. With multiple assistants, the patient is flipped prone onto the OR table while the CRNA commands at the head and secures the airway.

  3. Parallel thoracic or chest rolls (made from tightly rolled sheets and blankets or manufactured gel rolls) are placed under the thorax, lateral to the breasts, following the long line of the body to free the abdomen from compression.  Care is given not to compress the breasts with the rolls or cause undue pressure under the axilla.

  4. The head is positioned prone, with face placed in a foam prone-cutout pillow (with ETT, OGT and EGS exiting out the side), in a skull-pin head clamp, or in a rocker-based face/forehead rest.  It can alternatively be placed laterally, using a gel donut, pillow or blankets, while avoiding forced rotation of the pronated head .  Eyes, ears, and nose should be checked to assure that these areas are free from pressure.  Most important:  *The C-spine should be in neutral alignment (check for neutral position of the neck in all 3 planes).  The tube should be free without kinking or undue traction, and the anesthesia provider should be able to visually see or reach in and check all connections.

  5. The arms are padded and positioned to prevent nerve stretch or compression.  This can be accomplished in a variety of ways depending on the exact nature of the surgery and access required (check with the surgeon).  The arms are secured to prevent accidental dislocation or trauma from movement or falling off of table during the procedure. (See "Arm Positions" section for various placement of prone arms).

  6. Legs are maintained in the long axis of the body.  Knees should be padded with egg crate or gel.  Pillows should be placed under the calves and feet to take pressure off the lumbar spine and prevent pressure sores on toes. 

  7. The patient is secured to the table with tape or a belt across the thighs immediately under the buttocks.

  8. Break the table from the middle hinge at the hips, bringing both the thorax and thighs lower than the hips.  Caution should be taken to not allow the lower portion of the bed to hit the floor. The degree of flexion depends on surgeon preference, patient tolerability, and table surface hinges.



  • Compression ulcers:  orbital, ears, nose, elbows, iliac crests, knees, breasts and toes
  • Nerve damage:  axillary, brachial plexus, radial, ulnar,  popliteal, long thoracic
  • Thoracic outlet syndrome
  • Cervical Spine Injury
  • Breast trauma
  • Unstable chest wall
  • Venous congestion
  • Conjunctival edema