Analysis of risk factors for loss of lumbar lordosis in patients who had surgical treatment with segmental instrumentation for adolescent idiopathic scoliosis

Adolescent spine patients have an increased incidence of acetabular overcoverage

Changes in spino-pelvic alignment can lead to changes in acetabular coverage and predispose those with spinal pathologies to hip pathologies. The purpose of this study was to define the incidence of acetabular overcoverage in pediatric spine patients. Retrospective review of charts and EOS radiographs was conducted for patients ≤21 years old with adolescent idiopathic scoliosis (AIS) or Scheuermann’s Kyphosis (SK) who were treated with posterior spinal fusion (PSF) between 12/01/2015–7/26/2016. Radiographs were measured for lateral center edge angles (LCEA), anterior center edge angle (ACEA), and lumbar lordosis pre- and postoperatively. 32 patients met inclusion criteria. Preoperatively, mean LCEA was 44.1 degrees (range: 32–55, SD: 5.1) on the right and 42.8 degrees (range: 33–52, SD: 4.4) on the left. Mean preoperative ACEA was 56.0 degrees (range: 35–90, SD: 10.4). Mean preoperative lordosis was 56.0 degrees (range: −22–105, SD: 19.1) Preoperative LCEA was not associated with lordosis (right: r = 0.002, p = 0.78, left: r = 0.006, p = 0.66). Preoperative ACEA was no associated with lordosis (r = 0.02, p = 0.49). Overall, the mean percent change in LCEA was −3.4% (range: −19.6–21.9, SD: 10.3) on the right and −3.5% (range: −31.0–27.9, SD: 13.3) on the left. Mean percent change in ACEA was 9.1% (range: −20.6–35.7, SD: 15.1). Mean percent change in lordosis was −12.2% (range: −150–33.3, SD: 33.3. The incidence of acetabular overcoverage may be significantly higher in a pediatric spinal population than the general population. Careful monitoring of these patients for signs and symptoms of hip pathology may be warranted.

Predictors for Postoperative Loss of Lumbar Lordosis After Long Fusions Arthrodesis in Patients with Adult Scoliosis

Background

Loss of lumbar lordosis (LL) is closely related to clinical symptoms and operative complications, however, few studies have identified its predictors. The purpose of our study was to identify the predictors for loss of LL in patients with adult scoliosis and provided evidence for surgical decision-making.

Material/Methods

There were 69 patients with adult scoliosis who underwent long fusions arthrodesis from January 2006 to March 2015 included in this retrospectively study. The patients were divided into two cohorts according the average loss of LL: cohort LL (loss of LL below the average) and cohort GL (loss of LL above the average). Multivariate logistic regression analysis and the receiver operating characteristic curve were used to identify the predictors.

Results

There were statistically significant differences between the two cohorts in preoperative LL (p=0.002), postoperative LL (p=0.036), last follow-up LL (p<0.001), postoperative loss LL (p<0.001), preoperative SVA (p=0.007), last follow-up SVA (p=0.018), and pelvic incidence (p=0.016). Preoperative LL <23.5 (OR=0.920, 95% CI=0.870–0.973, p=0.003) and preoperative sagittal vertical axis >4.28 (OR=1.199, 95% CI=1.007–1.429, p=0.041) had good accuracy to predict postoperative loss of LL.

Conclusions

Loss of LL commonly occurred after long fusions arthrodesis in patients with adult scoliosis. Postoperative deteriorated sagittal balance was more frequently than deteriorated coronal balance. Preoperative LL <23.5 and preoperative SVA >4.28 were the predictors for postoperative greater loss of LL in patients after long fusions arthrodesis. More attention should be paid to how to maintain the LL in patients with preoperative predictors, especially if both the identified predictors are present.

Iatrogenic Flatback and Flatback Syndrome: Evaluation, Management, and Prevention

Flatback syndrome can be a significant source of disability, affecting stance and gait, and resulting in significant pain. Although the historical instrumentation options for thoracolumbar fusion procedures have been commonly regarded as the etiology of iatrogenic flatback, inappropriate selection, or application of modern instrumentation can similarly produce flatback deformities. Patients initially compensate with increased lordosis at adjacent lumbar segments and reduction of thoracic kyphosis. As paraspinal musculature fatigues and discs degenerate, maintaining sagittal balance requires increasing pelvic retroversion and hip extension. Ultimately, disc degeneration at adjacent levels overcomes compensatory mechanisms, resulting in sagittal imbalance and worsening symptoms. Nonoperative management for sagittally imbalanced (sagittal vertical axis>5 cm) flatback syndrome is frequently unsuccessful. Despite significant complication rates, surgical management to recreate lumbar lordosis using interbody fusions and/or osteotomies can significantly improve quality of life.

An analysis of spinopelvic sagittal alignment after lumbar lordosis reconstruction for degenerative spinal diseases: how much balance can be obtained?

STUDY DESIGN

A retrospective and radiological study of degenerative spinal diseases.

OBJECTIVE

To explore the changes in spinopelvic sagittal alignment after lumbar instrumentation and fusion of degenerative spinal diseases.

SUMMARY OF BACKGROUND DATA

Efforts have been paid to clarify the ideal postoperative sagittal profile for degenerative spinal diseases. However, little has been published about the actual changes of sagittal alignment after lumbar lordosis reconstruction.

METHODS

Radiographical analysis of 83 patients with spinal degeneration was performed by measuring sagittal parameters before and after operations. Comparative studies of sagittal parameters between short (1 level) and long (≥ 2 level) instrumentation and fusion were performed. Different variances (Δ) of these sagittal parameters before and after operations were calculated and compared. Correlative study and linear regression were performed to establish the relationship between variances.

RESULTS

No significant changes were shown in the short-fusion group postoperatively. In the long-fusion group, postoperative lumbar lordosis (LL) and sacral slope (SS) were significantly increased; pelvic tilt (PT), sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis, and PT/SS were significantly decreased. Different variances of ΔLL, ΔSS, ΔPT, ΔSVA, Δ(pelvic incidence - LL), and ΔPT/SS were significantly greater in the long-fusion group than the short-fusion group. Close correlations were mainly shown among ΔLL, ΔPT, and ΔSVA. Linear regression equations could be developed (ΔPT = -0.185 × ΔLL - 7.299 and ΔSVA = -0.152ΔLL - 1.145).

CONCLUSION

In degenerative spinal diseases, long instrumentation and fusion (≥ 2 levels) provides more efficient LL reconstruction. PT, SS, and SVA improve corresponding to LL in a linear regression model. Linear regression equations could be developed and used to predict PT and SVA change after long instrumentation and fusion for LL reconstruction.