Sagittal Balance and Spinopelvic Parameters After Lateral Lumbar Interbody Fusion for Degenerative Scoliosis

Abstract

Study Design Retrospective matched–cohort analysis. Objective To evaluate the change in radiographic parameters in patients undergoing interbody fusion and posterior instrumentation compared to posterior spine fusion alone (PSF) for degenerative scoliosis. Summary of Background Data Little is known about the effect of lateral interbody fusion (LIF) on sagittal plane correction in the setting of degenerative scoliosis. We performed a retrospective study to investigate these changes compared to PSF. Methods Between 1997 and 2011, 33 patients had LIF at 181 levels between T8 and L5 vertebrae for the treatment of degenerative scoliosis (mean; 5±2 levels). Of those, 23 patients had additional anterior lumbar interbody fusion (ALIF) at 37 levels between L4 and S1 vertebrae (mean; 1.6±0.5 levels). A 1:1 matched control of patients who underwent PSF was performed. Patients were matched by age, gender, and diagnosis. Clinical and radiographic data were collected and compared between the matched cohorts. Results Lumbar lordosis was significantly restored in LIF±ALIF compared to PSF cohort (44°±14° versus 36°±15°, p=0.02). The segmental lumbar lordosis over the 102 LIF levels significantly improved from 12°±10° to 21°±13° postoperatively (p<0.0001). However, the change over the 37 ALIF levels was not significant (from 30°±15° to 29°±9°, p=0.8). Sagittal plane alignment was improved in LIF±ALIF compared to PSF cohort and trended toward but did not reach significance (3.8±3.2 cm versus 6.2±5.7 cm, p=0.09). Sacral slope was significantly higher in LIF±ALIF compared to PSF cohort (33°±11° versus 28°±10°, p=0.03). Pelvic tilt was lower in LIF±ALIF compared to PSF cohort and trended toward but did not reach significance (22°±10° versus 26°±10°, p=0.08). Conclusion Lumbar lordosis and sacral slope were mildly but statistically improved in the interbody fusion cohort compared to PSF cohort. Sagittal alignment and pelvic tilt trended toward but did not reach statistical significance. Segmental lumbar lordosis was improved at LIF levels more than at ALIF levels.

Sagittal Balance Correction in Lateral Interbody Fusion for Degenerative Scoliosis

“…2 Lateral interbody fusion techniques have been shown to yield higher fusion rates and improvement in lumbar lordosis as well as less morbidity than conventional anterior and posterior approaches. 3,4 Sagittal balance is the center-of-mass vector of the spine determined by the reciprocal curves of thoracic kyphosis and lumbar lordosis. Restoration of sagittal balance has repeatedly been shown to portend superior outcomes in pain, function, and health-related quality of life following spine surgery.…”

“…Restoration of sagittal balance has repeatedly been shown to portend superior outcomes in pain, function, and health-related quality of life following spine surgery. 3,5 Interbody cages (synthetic implanted scaffolding into the disc spaces) are designed to re-create the natural lordosis of the lumbar spine that is frequently changed by the asymmetric degeneration of the discs and to normalize the overall sagittal balance of the spine.…”

Correction of severe spinopelvic mismatch: decreased blood loss with lateral hyperlordotic interbody grafts as compared with pedicle subtraction osteotomy

“…17,27,68,81 A number of studies have demonstrated the use of standard LLIF in the correction of mild sagittal-and coronal-plane deformities. 1,2,7,15,23,24,27,37,48,56,57,62 More advanced techniques involving the use of hyperlordotic cages with anterior longitudinal ligament (ALL) release and anterior column realignment (ACR) via a lateral technique allow for a significant gain in LL with the added benefit of coronal balance restoration and indirect neuroforaminal decompression at multiple levels in a single procedure. 11,14,41,46,47,52,71,75 Here we compare our series of patients undergoing PSO or multiple-level LLIF with ACR for the correction of ASD and examine intraoperative estimated blood loss (EBL), operative time, length of stay (LOS), and change in spinopelvic parameters as well as perioperative and postoperative complications.…”

Lumbar Lordosis Minus Thoracic Kyphosis

“…19,20 In our study, SVA was significantly correlated with age (r ¼ 0.285, P ¼ 0.001), maxLL (r ¼ À0.322, P < 0.001), PT (r ¼ 0.308, P < 0.001), LL-TK (r ¼ À0.500, P < 0.001), PI-LL (r ¼ 0.418, P < 0.001), and NRS (r ¼ 0.846, P < 0.001), whereas no significant correlations were observed in SVA and maxTK, SS, and PI (all P > 0.05). With the increase of patients' age, LL will be getting decreased due to the degeneration of spine, with many compensatory mechanisms involved to rebuild the sagittal balance.…”