The comprehensive anatomical spinal osteotomy and anterior column realignment classification.

OBJECTIVESpinal osteotomies and anterior column realignment (ACR) are procedures that allow preservation or restoration of spine lordosis. Variations of these techniques enable different degrees of segmental, regional, and global sagittal realignment. The authors propose a comprehensive anatomical classification system for ACR and its variants based on the level of technical complexity and invasiveness. This serves as a common language and platform to standardize clinical and radiographic outcomes for the utilization of ACR.METHODSThe proposed classification is based on 6 anatomical grades of ACR, including anterior longitudinal ligament (ALL) release, with varying degrees of posterior column release or osteotomies. Additionally, a surgical approach (anterior, lateral, or posterior) was added. Reliability of the classification was evaluated by an analysis of 16 clinical cases, rated twice by 14 different spine surgeons, and calculation of Fleiss kappa coefficients.RESULTSThe 6 grades of ACR are as follows: grade A, ALL release with hyperlordotic cage, intact posterior elements; grade 1 (ACR + Schwab grade 1), additional resection of the inferior facet and joint capsule; grade 2 (ACR + Schwab grade 2), additional resection of both superior and inferior facets, interspinous ligament, ligamentum flavum, lamina, and spinous process; grade 3 (ACR + Schwab grade 3), additional adjacent-level 3-column osteotomy including pedicle subtraction osteotomy; grade 4 (ACR + Schwab grade 4), 2-level distal 3-column osteotomy including pedicle subtraction osteotomy and disc space resection; and grade 5 (ACR + Schwab grade 5), complete or partial removal of a vertebral body and both adjacent discs with or without posterior element resection. Intraobserver and interobserver reliability were 97% and 98%, respectively, across the 14-reviewer cohort.CONCLUSIONSThe proposed anatomical realignment classification provides a consistent description of the various posterior and anterior column release/osteotomies. This reliability study confirmed that the classification is consistent and reproducible across a diverse group of spine surgeons.

Contribution of Lateral Interbody Fusion in Staged Correction of Adult Degenerative Scoliosis

OBJECTIVE: Lateral interbody fusion (LIF) is attractive as a less invasive technique to address anterior spinal pathology in the treatment of adult spinal deformity. Its own uses and benefits in treatment of adult degenerative scoliosis are undefined. To investigate the radiographic and clinical outcomes of LIF, and staged LIF and posterior spinal fusion (PSF) for the treatment of adult degenerative scoliosis patients, we analyzed radiographic and clinical outcomes of adult degenerative scoliosis patients who underwent LIF and posterior spinal fusion.METHODS: Forty consecutive adult degenerative scoliosis patients who underwent LIF followed by staged PSF at a single institution were retrospectively reviewed. Long-standing 36” anterior-posterior and lateral radiographs were taken preoperatively, at inter-stage, 3 months, 1 year, and 2 years after surgery were reviewed. Outcomes were assessed through the visual analogue scale (VAS), 36-Item Short Form Health Survey (SF-36), and Oswestry Disability Index (ODI).RESULTS: Forty patients with a mean age of 66.3 (range, 49–79) met inclusion criteria. A mean of 3.8 levels (range, 2–5) were fused using LIF, while a mean of 9.0 levels (range, 3–16) were fused during the posterior approach. The mean time between stages was 1.4 days (range, 1–6). The mean follow-up was 19.6 months. Lumbar lordosis was significantly restored from 36.4º preoperatively up to 48.9º (71.4% of total correction) after LIF and 53.9º after PSF. Lumbar coronal Cobb was prominently improved from 38.6º preoperatively to 24.1º (55.8% of total correction) after LIF, 12.6º after PSF respectively. The mean pelvic incidence-lumbar lordosis mismatch was markedly improved from 22.2º preoperatively to 8.1º (86.5% of total correction) after LIF, 5.9º after PSF. Correction of coronal imbalance and sagittal vertebral axis did not reach significance. The rate of perioperative complication was 37.5%. Five patients underwent revision surgery due to wound infection. No major perioperative medical complications occurred. At last follow-up, there were significant improvements in VAS, SF-36 Physical Component Summary and ODI scores.CONCLUSION: LIF provides significant corrections in the coronal and sagittal plane in the patients with adult degenerative scoliosis. However, LIF combined with staged PSF provides more excellent radiographic and clinical outcomes, with reduced perioperative risk in the treatment of adult degenerative scoliosis.

Contribution of Lateral Interbody Fusion in Staged Correction of Adult Degenerative Scoliosis

OBJECTIVE: Lateral interbody fusion (LIF) is attractive as a less invasive technique to address anterior spinal pathology in the treatment of adult spinal deformity. Its own uses and benefits in treatment of adult degenerative scoliosis are undefined. To investigate the radiographic and clinical outcomes of LIF, and staged LIF and posterior spinal fusion (PSF) for the treatment of adult degenerative scoliosis patients, we analyzed radiographic and clinical outcomes of adult degenerative scoliosis patients who underwent LIF and posterior spinal fusion. METHODS: Forty consecutive adult degenerative scoliosis patients who underwent LIF followed by staged PSF at a single institution were retrospectively reviewed. Long-standing 36” anterior-posterior and lateral radiographs were taken preoperatively, at inter-stage, 3 months, 1 year, and 2 years after surgery were reviewed. Outcomes were assessed through the visual analogue scale (VAS), 36-Item Short Form Health Survey (SF-36), and Oswestry Disability Index (ODI). RESULTS: Forty patients with a mean age of 66.3 (range, 49–79) met inclusion criteria. A mean of 3.8 levels (range, 2–5) were fused using LIF, while a mean of 9.0 levels (range, 3–16) were fused during the posterior approach. The mean time between stages was 1.4 days (range, 1–6). The mean follow-up was 19.6 months. Lumbar lordosis was significantly restored from 36.4º preoperatively up to 48.9º (71.4% of total correction) after LIF and 53.9º after PSF. Lumbar coronal Cobb was prominently improved from 38.6º preoperatively to 24.1º (55.8% of total correction) after LIF, 12.6º after PSF respectively. The mean pelvic incidence-lumbar lordosis mismatch was markedly improved from 22.2º preoperatively to 8.1º (86.5% of total correction) after LIF, 5.9º after PSF. Correction of coronal imbalance and sagittal vertebral axis did not reach significance. The rate of perioperative complication was 37.5%. Five patients underwent revision surgery due to wound infection. No major perioperative medical complications occurred. At last follow-up, there were significant improvements in VAS, SF-36 Physical Component Summary and ODI scores. CONCLUSION: LIF provides significant corrections in the coronal and sagittal plane in the patients with adult degenerative scoliosis. However, LIF combined with staged PSF provides more excellent radiographic and clinical outcomes, with reduced perioperative risk in the treatment of adult degenerative scoliosis.