Lumbar Sagittal Balance Restoration: Less Invasive?

History

A 68-year-old female presents with standing intolerance, neurogenic claudication and back pain. Her past medical history includes coronary artery disease, diabetes, hypertension, hypothyroidism, and atrial fibrillation.

Pretreatment Imaging

Imaging shows a prior L2-L5 laminectomy and failed noninstrumented posterolateral bony fusion at L2-L5 (Figures 1, 2). Listhesis is shown at L2-L3 and L3-L4; degenerative disc disease at L2-S1, and multilevel foraminal stenosis (Figure 2).

Figure 1. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 2. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com. Pretreatment spinopelvic parameters:

• Pelvic Incidence: 56-degrees
• Lumbar Lordosis: 12-degrees
• Spinopelvic Mismatch: 44-degrees

Examination

The patient presented awake/alert; full bilateral extremity strength; reflexes are absent bilaterally at the knees and ankles.

She ambulates using a walker and exhibited a pronounced forward-flexed gait. Hyperextension of the lumbar spine produces pain that radiates bilaterally into her buttocks and posterior thighs.

Diagnosis

Listhesis (L2-L3, L3-L4), degenerative disc disease (L2-S1), multilevel foraminal stenosis

Selected Treatment

We performed the surgery in two stages:

• Stage 1: Anterior lumbar interbody fusion, L2-S1
• Stage 2: Percutaneous pedicle screw fixation, L2-S2 (Figure 3)

Figure 3. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 4. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Figure 5. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com. The estimated blood loss was 125cc total, and the patient did not require a stay in the ICU.

Outcome

At 12 weeks postop, the patient is off narcotics and able to walk one mile to a mile and a quarter using only a cane. She has no leg pain or claudication. However, she reports mild right upper back pain.

Postoperative spinopelvic parameters:

• Pelvic Incidence: 56-degrees
• Lumbar Lordosis: 50-degrees
• Spinopelvic Mismatch: 6-degrees

Figure 6. Image courtesy of Joshua M. Ammerman, MD, and SpineUniverse.com.

Surgeons' Discussion Points

Joshua M. Ammerman, MD

Neurosurgeon

Washington Neurosurgical Associates

Patients who experience loss of sagittal alignment can experience many difficulties leading to decreased quality of life. Included is loss of horizontal gaze, reduced capacity to respond to disruptions in static balance, increased energy expenditure to maintain upright posture, and fatigue, pain and disability.

The pelvis regulates the alignment between the spine and the legs. The primary pelvic parameters are Pelvic Incidence (PI), Pelvic Tilt (PT), and Sacral Slope (SS). Therefore, PI = PT+SS.

Patients with a high PI require a larger lumbar lordosis to maintain normal sagittal balance. A difference between PI and lumbar lordosis of less than 9-degrees indicates optimal lumbar alignment (spinopelvic matching). Surgical correction of a lumber hypolorodosis should attempt to achieve a spinopelvic balance of less than 9-degrees.

Case Discussion

Christopher P. Silveri, MD, FAAOS

Orthopaedic and Neurological Spine Surgeon

Fair Oaks Orthopaedic Associates

The patient’s postoperative films demonstrate an excellent reconstruction of sagittal imbalance in a very difficult post-laminectomy deformity situation. My concern in these cases, and in this age group, is the significant central stenosis seen at L3-L4, and the rather severe foraminal stenosis throughout the deformity. Kudos if the interbody height restoration indirectly accomplished the decompression to the extent clinically needed.