Adult Sagittal and Coronal Imbalance: How to Correct?

History

The patient is a 50-year-old female. She is 5’2” and weighs 142 pounds. Her body mass index (BMI) is 26. The patient’s chief complaints are back pain and postural deformity.

The patient also has acid reflux and bundle branch block.

Examination

On examination, the patient is having difficulty maintaining an upright posture, and she cannot stand with her hips and knees fully extended without leaning forward.

There is an obvious loss of lumbar lordosis, but the patient has normal gait and neurological function.

Outcome

Her SVA score is + 11.4. The PI is 53°, and the pelvic tilt is 46°.

Table 1: Pre-op SRS Scores

Prior Treatment

The patient had 2 previous surgeries. In 1986, the patient had a Harrington rod implanted with PSF at T10-L4, and in 1991, she had PSF at L4-L5.

The patient has also tried physical therapy, anti-inflammatory medications, and acupuncture.

Pre-treatment Images

Figure 1: Pre-op clinical photos showing patient’s abnormal posture

Figure 2: Additional pre-op clinical photos showing patient’s spinal deformity

Figure 3: Pre-op x-ray showing left thoracolumbar scoliosis (left) and pre-op lateral x-ray (right)

Diagnosis 

The patient was diagnosed with post-surgical sagittal and coronal imbalance.

Selected Treatment

The surgery, which was done in one stage, involved an exploration of posterior spinal fusion and the removal of the patient’s Harrington Rod.

A pedicle subtraction osteotomy at L2 was done with titanium mesh cage fixation and segmental instrumentation at T5-S1 with left iliac screw. The surgery also involved a laminectomy, decompression, foraminotomy, and facetectomies at the L4-L5 nerve roots.

In addition, the patient had a lumbar discectomy at L4-L5 and L5-S1, a lumbar spinal fusion at L4-L5 and L5-S1 via the presacral approach, and an interbody fixation with rodded cages at L4-L5 and L5-S1.

Local bone, cancellous allograft, BMP, Grafton Matrix, and Grafton Putty were used.

Post-treatment Images

Figure 4: Post-op x-ray (left) and post-op lateral x-ray (right)

Figure 5: Posterior pre-op (left) and post-op (right) clinical photos

Figure 6: Lateral pre-op (left) and post-op (right) clinical photos

Outcome

The patient had less pain and deformity, which is evident in her post-op clinical photos.

Her SVA score is 0. The PI is 67 degrees, and the pelvic tilt is 30 degrees.

Table 2: HRQOL Outcomes

Case Discussion

Stephen Lewis, MD

Orthopaedic Spine Surgeon

Toronto Western Hospital and Hospital for Sick Children

This case demonstrates coronal and sagittal imbalance with the expected distal degeneration of the remaining motion segment. The patient has retroverted her pelvis to maximize her pelvic tilt to maintain upright posture, but despite this, she is required to flex her hips and knees as the deformity is too severe.

The patient requires decompression and fusion of her remaining mobile lumbar segments and correction of her sagittal plane deformity. Correction of her small coronal imbalance would be a secondary objective. Based on her pelvic incidence of 53° and her lumbar lordosis (T12-S1)of 8° of kyphosis, she requires approximately 51° of lordosis to bring her lumbar lordosis within 10° of her pelvic incidence. To achieve this, a single PSO at L2 can provide 30 to 40° of correction, and between positioning and interbody support at L5-S1, perhaps a further 10 to 15° of lordosis can be achieved to make up the remaining deficit.

A very nice correction was achieved in this case with this plan in mind. A posterior only L2 PSO was performed after removing the previous implants, and the required interbody support was achieved through an AxiaLIF. While my preference would have been bilateral iliac fixation and a PLIF at L5-S1, the AxiaLIF and unilateral iliac fixation are acceptable options. The surgeon was able to achieve 50° of lumbar lordosis and excellent balance in the coronal and sagittal planes. The patient has gone on to an excellent clinical and radiographic outcome.