Dynamic sagittal balance in patients with adult spinal deformity

Object The treatment of adult spinal deformity (ASD) remains a challenge for the spine surgeon. While minimally invasive surgery (MIS) has many favorable attributes that would be of great benefit for the ASD population, improvements in lordosis and sagittal balance have remained elusive in cases involving the MIS approach. This report describes the evolution of an MIS method for treating ASD with attention to sagittal correction. Methods Over an 18-month period 25 patients with thoracolumbar scoliosis were treated surgically. The mean patient age was 72 years, and 68% of the population was female. Patients were treated with multilevel facet osteotomies and interbody fusion in which expandable cages (mean 3.2 levels) were placed and percutaneous screw fixation (mean 5.3 levels) was performed. Seven patients underwent supplemental percutaneous iliac fixation. Results All patients underwent MIS without conversion to a traditional open procedure. The mean operative time was 273 mins and the mean blood loss was 416 ml. There were no intraoperative complications. The Cobb angle over the scoliotic deformity improved from a mean of 29.2° to that of 9.0° (p < 0.001). Lumbar lordosis between L-1 and S-1 improved from a mean of 27.8° to one of 42.6° (p < 0.001). Sagittal vertical axis improved from 7.4 cm to 4.3 cm (p = 0.001). Numeric pain scale scores improved as well, an average of 3.3 and 4.2 for the leg and back, respectively. A mean improvement of 20.8 points on the Oswestry Disability Index was seen at 12 months. Complications included: two cases requiring hardware repositioning, one case of screw pullout, one asymptomatic pedicle screw breach, prolonged hospitalization from constipation, and one acute coronary syndrome developing 3 days after surgery without myocardial damage. Conclusions An expanding body of evidence suggests that sagittal balance remains a keystone for good outcomes after ASD surgery. Minimally invasive surgery that involves a combination of osteotomies, interbody height restoration, and advanced fixation techniques may achieve this goal in patients with less severe deformities. While feasibility will have to be proven with larger series and improved surgical methods, the present technique holds promise as a means of reducing the significant morbidity associated with surgery in the ASD population.

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Evolution of Sagittal Imbalance Following Corrective Surgery for Sagittal Plane Deformity

Neurosurgery ◽

10.1093/neuros/nyx145 ◽

2017 ◽

Vol 81 (1) ◽

pp. 129-134 ◽

Cited By ~ 4

Author(s):

Michael M. McDowell ◽

Zachary J. Tempel ◽

Gurpreet S. Gandhoke ◽

Nicholas K. Khattar ◽

D. Kojo Hamilton ◽

...

Keyword(s):

Clinical Outcomes ◽

Spinal Deformity ◽

Sagittal Balance ◽

Pelvic Tilt ◽

Short Form ◽

Adult Spinal Deformity ◽

Sagittal Imbalance ◽

Consecutive Series ◽

Adult Deformity ◽

Global Sagittal Alignment

Abstract BACKGROUND: Sagittal balance in adult spinal deformity is a major predictor of quality of life. A temporary loss of paraspinal muscle force and somatic pain following spine surgery may limit a patient's ability to maintain posture. OBJECTIVE: To assess the evolution of sagittal balance and clinical outcomes during recovery from adult spinal deformity surgery. METHODS: Retrospective review of a prospective observational database identified a consecutive series of patients with sagittal vertical axis (SVA) > 40 mm undergoing adult deformity surgery. Radiographic parameters and clinical outcomes were measured out to 2 yr after surgery. RESULTS: A total of 113 consecutive patients met inclusion criteria. Mean preoperative SVA was 90.3 mm, increased to 104.6 mm in the first week, then gradually reduced at each follow-up interval to 59.2 mm at 6 wk, 45.0 mm at 3 mo, 38.6 mm at 6 mo, and 34.1 mm at 1 yr (all P < .05). SVA did not change between 1 and 2 yr. Pelvic incidence-lumbar lordosis (PI-LL) corrected immediately from 25.3° to 8.5° (16.8° change; P < .01) and a decreased pelvic tilt from 27.6° to 17.6° (10° change; P < .01). No further change was noted in PI-LL. Pelvic tilt increased to 20.2° (P = .01) at 6 wk and held steady through 2 yr. Mean Visual Analog Scale, Oswestry Disability Index, and Short Form-36 scores all improved; pain rapidly improved, whereas disability measures improved as SVA improved. CONCLUSION: Radiographic assessment of global sagittal alignment did not fully reflect surgical correction of sagittal balance until 6 mo after adult deformity surgery. Sagittal balance initially worsened then steadily improved at each interval over the first year postoperatively. At 1 yr, all clinical and radiographic measures outcomes were significantly improved.

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