Posterior Lateral Lumbar Arthrodesis

A posterior lateral lumbar arthrodesis (PLSA) is a minimally invasive surgical procedure that stabilizes one level in the lower back. Unlike traditional fusion surgery, a PLSA does not require large incisions, muscle stripping, screws, or rods. The procedure uses a specialized implant, such as the Minuteman®, that is placed between the bony projections at the back of the spine (spinous processes). Bone graft material is packed around the device to achieve arthrodesis.

This procedure prevents unwanted motion in the affected segment of the spine, providing stability and pain relief. The implant is designed to fit securely and comes in multiple sizes to match the patient’s anatomy.

A posterior lateral lumbar arthrodesis is typically used to treat the following conditions. In each case, the implant reduces painful motion, restores stability, and helps relieve pressure on irritated nerves.

Lumbar Spinal Stenosis
Spinal stenosis occurs when the spinal canal narrows and compresses the nerves. By stabilizing the affected level, the implant reduces inflammation caused by segmental movement and prevents further narrowing during motion. The device also creates additional space between the spinous processes, indirectly reducing nerve irritation and helping relieve leg and back pain associated with stenosis.

Lumbar Degenerative Disc Disease (DDD)
When a disc degenerates, it loses height and shock absorption, causing painful “micro-motions” between vertebrae. The implant limits these excessive movements by locking the segment into a stable position. By eliminating the painful motion and promoting bone growth, the device reduces chronic low-back pain and restores biomechanical stability to the affected level.

Lumbar Spondylolisthesis
In spondylolisthesis, one vertebra slips forward over the one below it, creating instability and nerve compression. The implant helps by securing the spinous processes and preventing further slippage. By stabilizing the vertebrae and holding them in proper alignment, the device reduces nerve irritation and provides the stability needed for the bone graft to successfully fuse the segment.

A specialized implant is placed during surgery to stabilize the spine. Here’s how it works:

Minimally Invasive Placement 
The implant is inserted through a small side or lateral incision, protecting the natural anatomy and not cutting the ligaments or multifidus muscles. This means less pain, faster recovery, and fewer opportunities for infection.

Secure Support 
The implant’s design locks into place between the spinous processes to keep the spine stable during healing.

Bone Graft Integration
Bone graft material is placed around the implant to promote bone growth and long-term stability.

Durable Design 
The threaded and contoured body of the device allows for secure attachment and precise placement during surgery.

Together, these features help stabilize the spine, reduce motion at the treated level, and relieve nerve irritation that causes pain.

This procedure is performed using a minimally invasive approach that avoids cutting through large muscle groups and does not require nerve monitoring. Because it preserves important spinal structures like the supraspinous ligament, the surgery is generally less traumatic than traditional open fusion techniques.

Most patients can expect a shorter procedure time, less blood loss, and reduced recovery periods compared to traditional open surgery. As the implant encourages bone growth, pain levels often decrease and spinal stability improves over time.

The long-term outlook for patients undergoing posterior lateral lumbar arthrodesis is generally positive. Once the segment becomes stable, patients report significantly reduced pain and improved function. With proper post-operative care and adherence to medical instructions, patients typically experience lasting improvements in quality of life.

The implant is also MRI-safe under specified conditions, allowing for ongoing imaging and monitoring of the spine as needed.