Oblique Lateral Interbody Fusion (OLIF) is a minimally invasive spinal fusion surgery. It is designed to address conditions such as degenerative disc disease and instability in the lumbar spine. The procedure involves accessing the spine from the side of the body to place a supportive implant between vertebrae, which helps to restore height and stability. The precise positioning of the patient is a meticulously planned element of the surgery.
The Standard OLIF Surgical Position
For an OLIF procedure, the patient is placed in a lateral decubitus position, which means they are lying on their side. For a left-sided surgical approach to the spine, the patient is positioned in the right lateral decubitus position, meaning they are lying on their right side. This orientation provides the surgeon with optimal access to the targeted spinal levels.
Once on their side, the patient is situated on a specialized operating table that can be adjusted. The table is often “broken” or flexed, creating a gentle arch in the patient’s torso. This maneuver increases the distance between the bottom of the rib cage and the top of the hip bone, or iliac crest. Widening this flank space is an important step that directly facilitates the surgeon’s access to the lower spine.
The specific angle of approach is oblique, meaning it is diagonal. The incision is typically made about 5 centimeters forward from the midpoint of the disc. This angulation is a defining feature of the OLIF technique.
The Process of Patient Positioning
After the patient is under anesthesia, the surgical team begins the deliberate process of positioning. The team works together to carefully roll the patient onto their side, maintaining alignment of the spine, neck, and head throughout the movement.
Securing the patient to the surgical table is a priority to prevent any movement during the operation. Wide, strong tape is often applied across the hips and sometimes the shoulders, anchoring the patient firmly to the table. This taping method provides stability without creating undue pressure on the skin or underlying tissues.
Extensive padding is used to protect areas susceptible to pressure. The arms are carefully positioned, often with the top arm supported in a padded holder, to prevent any strain on the brachial plexus nerves.
Surgical Access and Anatomic Corridor
By having the patient on their side, gravity helps to move the abdominal contents forward and away from the spine. This positioning, combined with the flexion of the table, opens a natural pathway to the lumbar vertebrae from an oblique angle. This corridor allows the surgeon to reach the spine with minimal disruption to surrounding tissues.
A significant advantage of this approach is its relationship to the psoas muscle, a large muscle that runs along the side of the lumbar spine. The OLIF technique allows the surgeon to work in a window between the psoas muscle and the major blood vessels located at the front of the spine. This path avoids the need to cut through or retract the psoas muscle itself.
This muscle-sparing corridor is what makes the OLIF a minimally invasive option. Inside the psoas muscle lie the major nerves of the lumbar plexus, which control sensation and movement in the legs. By staying in front of this muscle, the risk of injury to these nerves is significantly reduced compared to other lateral approaches that require dissection through the psoas.
Safeguards During Patient Positioning
Specific safety protocols are in place to mitigate risks associated with the lateral decubitus position. One primary concern is the development of pressure sores, or decubitus ulcers, which can form on the skin over bony areas due to prolonged pressure. The extensive use of specialized gel and foam padding at all pressure points, including the ankles, knees, and elbows, is the main countermeasure.
Another focus is the prevention of nerve compression injuries. The brachial plexus, a network of nerves in the shoulder, is particularly vulnerable in the downside arm. An axillary roll placed just below the armpit creates space and prevents the head of the humerus from compressing these nerves. Similarly, care is taken to pad the area around the fibular head, near the knee, to protect the peroneal nerve from compression against the operating table.
The anesthesia team plays a continuous role in monitoring the patient’s status throughout the procedure. They regularly check the positioning of the patient’s limbs and ensure that all protective measures remain effective. This includes confirming that there is no undue strain on the neck or back.