Posterior Spinal Fusion with Pedicle Screws

Understanding Normal Lumbar Discs

The spine in the lower (lumbar) back consists of the bony vertebrae, discs, nerves and other structures. The vertebrae, which stack up to create the spinal column, surround and protect the spinal cord and nerve roots. The end of the spinal cord (conus) is near the top of the lumbar spine. Below this, the nerve roots hang down in individual strands. These nerve roots, when viewed together, are somewhat similar in appearance to a horse’s tail, so the term used to describe them is cauda equina. The nerve roots travel out small bony windows (foramenae). The discs are located between each vertebra. Discs consist of a fibrous outer layer (annulus) surrounding a gelatinous center (nucleus). They allow motion between vertebrae, act as shock absorbers, and distribute the stress and strain placed on the spine

Common Lumbar Spine Conditions

Herniated Disc: occurs when the outer layer of a lumbar disc weakens or tears, allowing the inner material to bulge or protrude. This herniation can compress nearby nerve roots, causing symptoms like lower back pain, leg pain (sciatica), numbness, tingling, or muscle weakness. Degenerative changes, trauma, or natural aging may lead to conditions such as:

Degenerative Disc Disease: As discs lose moisture and protein content with age, they become thinner and more fragile. This degeneration can reduce disc height and compress nerves, leading to pain, weakness, or numbness, especially with walking or standing.

Spondylolisthesis: In this condition, one vertebra slips forward over the one below it. It can result from degeneration, trauma, or a non-healing crack in the vertebra. This slippage may compress nerve roots and cause symptoms of back or leg pain.

Lumbar Stenosis: This refers to narrowing of the spinal canal, often caused by disc degeneration or arthritic changes. When severe, it can irritate nerve roots and, in rare cases, cause cauda equina syndrome. Symptoms of this emergency condition include bowel or bladder dysfunction, leg weakness, and numbness in the saddle region. Immediate medical attention is required if these signs appear.

Treatment Options for Herniated Lumbar Discs

Most cases of back or leg pain related to lumbar disc problems improve with non-surgical treatment. These options may include:

  • Anti-inflammatory medications
  • Physical therapy and core strengthening
  • Activity modification and short rest periods
  • Ice or heat therapy
  • Epidural steroid injections to reduce inflammation and allow nerves to heal

If conservative measures fail or if neurological symptoms worsen, surgery may be recommended.

Posterior Spinal Fusion with Pedicle Screws

Posterior spinal fusion with pedicle screws is a surgical procedure used to stabilize the spine and reduce pain caused by spinal instability, fractures, deformities, or degenerative conditions. The term “posterior” refers to the back of the body—this is where the surgeon accesses the spine. During the procedure:

  • The surgeon makes an incision along the midline of the lower or middle back.
  • Muscles are gently moved aside to expose the bones of the spine.
  • Pedicle screws are inserted into the vertebrae on both sides of the spine.
  • Metal rods are attached to the screws to hold the bones in proper alignment.
  • A bone graft or a special cage filled with bone material is placed between the vertebrae to help them fuse together.

Over time—typically several months—the vertebrae grow together, forming a single solid bone. This fusion eliminates movement between those segments, which can significantly reduce pain and prevent further damage.

Posterior spinal fusion is often recommended when there is instability in the spine due to injury, severe arthritis, scoliosis, or after disc removal. The procedure can help relieve back pain, leg pain, weakness, and improve function and quality of life.

Potential Risks of Lumbar Fusion Surgery

Although PSF is a safe and commonly performed procedure, all surgeries carry risks. These include:

  • Nerve or spinal cord injury: Rare but may result in temporary or permanent weakness, pain, or sensory changes.
  • Failure of fusion: If the bone graft does not heal properly, the spine may not stabilize. Smoking greatly increases this risk. Refraining from tobacco use before and after surgery is strongly advised.
  • Dural tear: A tear in the spinal fluid sac may lead to leakage, sometimes requiring further surgery.
  • Infection: Occurs in about 1–2% of cases. Preventive antibiotics and careful wound care reduce this risk.
  • Vascular or bowel injury: Extremely rare but possible due to the surgical approach near abdominal structures.
  • Other risks: Blood clots, pneumonia, and anesthesia-related complications may occur, though they are uncommon. uncommon.

Postoperative Recovery and Rehabilitation

  • Walking and Daily Activity: Rehabilitation starts immediately with walking, which improves circulation, reduces complications, and supports healing. Most patients can walk for fifteen minutes twice daily by their first follow-up visit. By six weeks, the goal is thirty to forty minutes twice daily.
  • Strength Building and Neck Movement: Many patients have deconditioned muscles due to chronic pain. Strengthening exercises are introduced gradually. Gentle back range of motion is allowed, but twisting, heavy lifting, and sudden movements should be avoided during early recovery.

Anterior / Posterior Fusion Surgery

Patients typically notice significant improvement in leg and back pain following LLIF. Relief from nerve-related symptoms may be immediate or develop gradually as inflammation subsides and healing occurs.

  • Pain relief: Most patients experience marked improvement in leg pain.
  • Strength and coordination: These usually improve progressively as nerve function recovers.
  • Numbness: May take time to resolve, especially if present for a long duration before surgery.
  • Incision discomfort: Usually improves within two to three weeks.
  • Driving: Avoid until you are no longer taking narcotic pain medication and are cleared by your physician, usually about three weeks after surgery.

Wound Care and Medication Management

During your first post-operative visit, the incision will be evaluated and any necessary stitches will be removed.

  • Avoid soaking the incision in water. This means no baths, hot tubs, or swimming until cleared by your doctor.
  • If covered by a clear plastic dressing, it can be removed at home, and showering may begin right away.
  • If using a gauze dressing, wait seventy-two hours before showering and only if the wound remains dry. Pat the area dry after showering and apply a clean bandage.

Pain medications may cause constipation. To minimize this, increase your intake of water, fruits, vegetables, and whole grains. Regular walking can also help.

For refills, request them through your pharmacy and allow up to forty-eight hours. Refills will not be processed on weekends or after office hours, so plan ahead.

Do not soak your wound. No bathtub, swimming, or hot tub, etc. until you have received permission from your physician.

  • If you have a clear plastic bandage over your wound, you may shower right away. You may remove the clear plastic on arrival home, and then you may shower as listed below.
  • If you have no clear plastic, but instead have a gauze dressing, you may not shower until 72 hours after your surgery and only if your bandage does not have wet drainage on it.

To shower: simply remove the outer gauze bandage and shower as usual. Blot the incision dry, and then cover it with a clean, dry bandage.

Activity Guidelines After Surgery

Avoid twisting, bending, or forcing back movement in any direction. Gentle neck mobility is encouraged, but only within comfort limits. Driving should not resume until your physician has given approval.

Activity Limitations

Avoid twisting your back to the extremes, and avoid forced bending of your back either forward or backward. Gentle range of motion of the back is OK. Do not drive until you have received permission from your physician.

Treatment

Call the spine center if you are experiencing the following:

  • Difficulty breathing
  • Temperature greater than 101.5°F (38.5° C)
  • Changes in or difficulty with balance while walking
  • Increased weakness or numbness to your arms or legs
  • Increased or unusual pain not relieved by pain medication
  • Increased redness, swelling, bleeding, or other drainage at your incision site
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Meet our Doctors

Amir Vokshoor, MD, FAANS

Dr. Amir Vokshoor is a board-certified neurosurgeon specializing in minimally invasive surgical treatments. With over 20 years of dedicated experience, he is a leading advocate for advancements in the field, recognized for his expertise in…

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Jared D. Ament, MD, MPH, FAANS, FACS

Dr. Jared D. Ament is a Board-Certified, fellowship-trained neurosurgeon known as the “anti-fusion doctor” for his advocacy of motion-preserving spine surgery. He specializes in…

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