1.3 Surgical Positioning: Lithotomy, Jackknife, and Specialized Tables

Surgical Positioning: Lithotomy, Jackknife, and Specialized Tables

Quick Answer: Complex surgical procedures often require extreme modifications of basic anatomical positions. The Lithotomy and Kraske (Jackknife) positions, along with the use of orthopedic fracture tables, present unique challenges. The CSFA must master the mechanics of specialized positioning equipment, particularly stirrups, to prevent severe nerve injuries, joint dislocations, and crush injuries during these high-risk setups.

While supine and lateral positions are common, certain anatomical regions—such as the perineum, rectum, vagina, and specific orthopedic fracture sites—demand highly specialized positioning techniques. These positions carry an elevated risk of iatrogenic (provider-caused) injury if executed improperly.

The Lithotomy Position

The lithotomy position is used for gynecological, urological, and lower gastrointestinal procedures (e.g., vaginal hysterectomy, cystoscopy, abdominoperineal resection). The patient is supine with their legs raised and abducted in stirrups.

Mechanics of Lithotomy

• Coordination is Key: The legs must be raised and lowered simultaneously by two people. Moving one leg at a time can cause severe strain on the lumbar spine and pelvic joints, potentially leading to sacroiliac (SI) joint dysfunction or hip dislocation.
• Hemodynamic Shifts: When the legs are elevated, a significant volume of blood (autotransfusion) returns to the heart. When the legs are lowered at the end of the procedure, blood rushes back into the lower extremities. If lowered too quickly, this massive shift can cause a dangerous drop in blood pressure (hypotension). Legs must be lowered slowly and simultaneously.
• Stirrup Types:
  • Candy Cane Stirrups: Support the foot and ankle via a strap. They require careful padding around the foot to prevent plantar nerve damage.
  • Allen/Boot Stirrups: Support the entire foot and calf. These distribute pressure more evenly and are preferred for prolonged cases.

Nerve Vulnerabilities in Lithotomy

1. Common Peroneal Nerve: Located on the lateral aspect of the knee (specifically, wrapping around the fibular head). It is easily crushed against the hard metal bars of the stirrups. Damage results in foot drop.
2. Obturator Nerve: Can be stretched if the hips are hyper-abducted (spread too wide).
3. Femoral Nerve: Can be injured by extreme hyperflexion of the hips.
4. Sciatic Nerve: Can be stretched if the hips are hyperflexed while the knees are fully extended.

The Kraske (Jackknife) Position

The Kraske position is a modification of the prone position. The patient is placed face down, and the operating table is flexed in the middle (forming an inverted V) to elevate the hips. It is utilized primarily for proctological procedures (e.g., hemorrhoidectomy, pilonidal cyst excision, gluteal tumor resections).

Key Considerations for Kraske

• Hemodynamics: Blood pools in the dependent extremities (head and legs). Returning the patient to a flat prone or supine position rapidly can cause severe hypotension.
• Padding and Support: The patient requires the same chest rolls used in the standard prone position to allow for ventilation. Additionally, wide strips of adhesive tape are often used to pull the buttocks apart for exposure; this tape must be applied carefully to avoid skin tearing, and it is usually anchored to the sides of the operating table.
• Groin and Genital Protection: The table break occurs directly under the hips. For male patients, the genitalia must be carefully checked to ensure they are free from compression between the legs and the table pad.

Specialized Tables: The Fracture Table

Orthopedic trauma procedures, particularly fixation of femoral neck or intertrochanteric fractures, utilize a specialized fracture table. This table allows the surgeon to apply mechanical traction to the leg to align the broken bone while providing unhindered C-arm fluoroscopy access.

Key Considerations for Fracture Tables

• The Perineal Post: A padded cylindrical post is placed vertically between the patient's legs at the perineum. This post acts as a counter-traction point when the injured leg is pulled downward. If this post is inadequately padded or the patient is positioned incorrectly, massive pressure is exerted on the perineum, leading to crushing injuries of the pudendal nerve and severe damage to the genitalia.
• Boot Traction: The foot of the injured leg is secured in a traction boot. The CSFA must ensure the foot is well-padded to prevent heel ulcers and compression of the dorsalis pedis artery.
• Uninjured Leg: The unaffected leg is typically elevated and placed in a specialized stirrup or scissor attachment to keep it out of the fluoroscopy field.

Safety Straps and General Restraints

Regardless of the position, the patient must be secured to the operating table to prevent falls, especially during table tilting or unexpected shifting.

• Placement: The safety strap should be placed approximately 2 inches above the knees over the distal thighs. It must never be placed directly over the patella (kneecap) or tightly across the abdomen.
• Tension: The strap should be snug, allowing two fingers to slip easily between the strap and the patient. If it is too tight, it can restrict venous return and cause deep vein thrombosis (DVT) or nerve compression.
• Arm Restraints: When arms are tucked at the sides, they must be wrapped in a draw sheet (a "tuck"). The draw sheet must pass under the patient's body, not just under the mattress, to ensure security.

The meticulous application of these principles separates an adequate assistant from a master surgical first assistant. Protecting the patient from positional injury is as critical as the surgery itself.