Commentary: Artificial Intelligence for Adult Spinal Deformity

Lawrence G. Lenke 대한척추신경외과학회 2019 Neurospine Vol.16 No.4

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The Incidence of Adding-On or Distal Junctional Kyphosis in Adolescent Idiopathic Scoliosis Treated by Anterior Spinal Fusion to L3 Was Significantly Higher Than by Posterior Spinal Fusion to L3

현승재,Lawrence G. Lenke,김용정,Keith H. Bridwell,Meghan Cerpa,Kathy M. Blanke 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Objective: To compare and identify risk factors for distal adding-on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by anterior- (ASF) and posterior spinal fusion (PSF) to L3. Methods: AIS patients undergoing ASF versus PSF to L3 from 2000–2010 were analyzed. Distal AO and DJK were deemed poor radiographic results. New stable (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores. Results: Twenty of 42 (ASF group: 47.6%) and 8 of 72 patients (PSF group: 11.1%) showed poor radiographic outcome. Fused vertebrae, correction rate of main curve, coronal reduction rate of L3 were significantly higher in PSF group. Multiple logistic regression results indicated that preoperative SV-3 at L3 in standing and side benders (odds ratio [OR], 2.7 and 3.7, respectively), TS score -5, -6 at L3 (OR, 4.9), rigid disc at L3–4 (OR, 3.7), lowest instrumented vertebra (LIV) rotation >15° (OR, 3.3), LIV deviation >2 cm from center sacral vertical line (OR, 3.1) and ASF (OR, 13.4; p<0.001) were independent predictive factors. There was significant improvement of the Scoliosis Research Society (SRS)-22 average scores only in PSF group. Furthermore, the ultimate scores of PSF group were significantly superior to ASF group. Conclusion: The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was significantly higher in ASF group. Ultimate SRS-22 scores were significantly better in PSF group.

Adolescent Idiopathic Scoliosis Treated by Posterior Spinal Segmental Instrumented Fusion : When Is Fusion to L3 Stable?

Hyun, Seung-Jae,Lenke, Lawrence G.,Kim, Yongjung,Bridwell, Keith H.,Cerpa, Meghan,Blanke, Kathy M. The Korean Neurosurgical Society 2021 Journal of Korean neurosurgical society Vol.64 No.5

Objective : The purpose of this study was to identify risk factors for distal adding on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by posterior spinal fusion (PSF) to L3 with a minimum 2-year follow-up. Methods : AIS patients undergoing PSF to L3 by two senior surgeons from 2000-2010 were analyzed. Distal AO and DJK were deemed poor radiographic results and defined as >3 cm of deviation from L3 to the center sacral vertical line (CSVL), or >10° angle at L3-4 on the posterior anterior- or lateral X-ray at ultimate follow-up. New stable vertebra (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores. Results : Ten of 76 patients (13.1%) were included in the poor radiographic outcome group. The other 66 patients were included in the good radiographic outcome group. Lower Risser grade, more SV-3 (CSVL doesn't touch the lowest instrumented vertebra [LIV]) on standing and side bending films, lesser NV and TS score, rigid L3-4 disc, more rotation and deviation of L3 were identified risk factors for AO or DJK. Age, number of fused vertebrae, curve correction, preoperative coronal/sagittal L3-4 disc angle did not differ significantly between the two groups. Multiple logistic regression results indicated that preoperative Risser grade 0, 1 (odds ratio [OR], 1.8), SV-3 at L3 in standing and side benders (OR, 2.1 and 2.8, respectively), TS score -5, -6 at L3 (OR, 4.4), rigid disc at L3-4 (OR, 3.1), LIV rotation >15° (OR, 2.9), and LIV deviation >2 cm from CSVL (OR, 2.2) were independent predictive factors. Although there was significant improvement of the of Scoliosis Research Society-22 average scores only in the good radiographic outcome group, there was no significant difference in the scores between the groups. Conclusion : The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was 13.1%. To prevent AO or DJK following fusion to L3, we recommend that the CSVL touch L3 in both standing and side bending, TS score is -4 or less, the L3/4 disc is flexible, L3 is neutral (<15°) and ≤2 cm from the midline and the patient is ≥ Risser 2.

Selection of the Lowest Instrumented Vertebra and Relative Odds Ratio of Distal Adding-on for Lenke Type 1A and 2A Curves in Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-analysis

Che-Wei Liu,Lawrence G. Lenke,Lee A. Tan,Taemin Oh,Kou-Hua Chao,Shi-Ding Lin,Ru-Yu Pan 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Objective: To examine existing literature and pool the data to determine the relative odds ratio of “adding-on” (AO) based on various reported criteria for lower instrumented vertebra (LIV) selection in Lenke type 1A and 2A curves. Methods: Using electronic databases, studies reporting on AO and LIV selection in Lenke type 1A and 2A curves were identified. Studies were excluded if they failed to meet the following criteria: ≥30 patients, Lenke type 1A or 2A curves, thoracic-only fusions, and inclusion of outcome differences in AO and non-AO groups. Review articles, letters, and case reports were excluded. Results: Six studies were identified reporting on 732 patients with either Lenke type 1A or 2A curves treated with thoracic-only fusions. Five different landmarks were used for LIV selection in these studies including the stable vertebra (SV) -1, end vertebra (EV) +1, neutral vertebra (NV), touched vertebra (TV), and substantially touched vertebra (STV) versus nonsubstantially touched vertebra (nSTV) +1. The pooled odds ratios of AO for choosing LIV at levels above the afore landmarks (i.e., ending the construct “short”) versus at the landmarks were 2.59 (SV-1), 2.43 (EV+1), 3.05 (NV), 3.40 (TV), and 4.52 (STV/nSTV+1), all at 95% confidence interval. Conclusion: Five landmarks shared a similar characteristic in that the incidence of AO was significantly higher if the LIV was proximal to the chosen landmark. In addition, choosing STV/(nSTV+1) as the LIV have the lowest absolute risk of AO and the greatest risk reduction. If additional levels were fused (i.e., LIV distal to the landmark), there was no statistically significant benefit in further reducing the risk of AO. Selection of the optimal LIV is a complex issue and spine surgeons must balance the risk of AO with the need for motion preservation in young patients.

The Hybrid Open Muscle-Sparing Approach in Adult Spinal Deformity Patients Undergoing Lower Thoracic Fusion to the Pelvis

Paul J. Park,Joe M. Lombardi,Lawrence G. Lenke 대한척추신경외과학회 2021 Neurospine Vol.18 No.1

Proximal junctional kyphosis (PJK) is a difficult complication to manage following adult spinal deformity surgery. Particularly in spinal fusions from the lower thoracic spine down to pelvis, PJK is a major consideration. While the open posterior approach allows for excellent visualization and preparation of bony surfaces for fusion, disruption of posterior soft tissue structures increases risk of PJK postoperatively. Minimally invasive approaches, on the other hand, preserve posterior ligamentous structures and musculature at the proximal fusion levels however prevent the access afforded by an open approach. We describe here the hybrid open muscle-sparing approach—a technique that allows for decortication of bony surfaces as well as clear exposure of anatomic landmarks for freehand pedicle screw placement, while protecting the posterior soft tissue structures to reduce risk of PJK.

Management of Pseudarthrosis With Implant Failure at a Multilevel Vertebral Column Resection Site: A Case Report

Venkat Boddapati,Joseph M. Lombardi,Lawrence G. Lenke 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Pseudarthrosis in the setting of 3-column osteotomies such as vertebral column resection (VCR) is not well described, and pseudarthrosis at the VCR site itself has never been reported. This study reports pseudarthrosis with 4-rod implant failure at a multilevel VCR site. The authors report a case of pseudarthrosis in a patient treated previously for severe segmental thoracolumbar kyphosis resulting in significant pain and myelopathic signs in the setting of radiation therapy for metastatic myeloma. This patient initially underwent 2-level VCR (T11, T12) and fusion from T4-sacrum. This was complicated by pseudarthrosis and associated with same-level 4-rod fracture, resulting in prominent, painful implants, and worsening kyphosis. This patient underwent revision VCR during which time significant motion was found only at the site of the prior VCR with a loose anterior cage. A new expandable VCR cage was placed and the spine was reinstrumented, resulting in significant improvement in coronal and sagittal alignment. Pseudarthrosis at a VCR site has not been previously described. Technical considerations presented in the revision procedure include a 6-rod spanning construct, meticulous endplate repreparation, and the generous use of osteo-inductive and -conductive augments to promote solid fusion.

Adult Spinal Deformity: A Comprehensive Review of Current Advances and Future Directions

Kim Hong Jin,Yang Jae Hyuk,Chang Dong-Gune,Lenke Lawrence G.,Suh Seung Woo,Nam Yunjin,Park Sung Cheol,Suk Se-Il 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.5

Owing to rapidly changing global demographics, adult spinal deformity (ASD) now accounts for a significant proportion of the Global Burden of Disease. Sagittal imbalance caused by age-related degenerative changes leads to back pain, neurological deficits, and deformity, which negatively affect the health-related quality of life (HRQoL) of patients. Along with the recognized regional, global, and sagittal spinopelvic parameters, poor paraspinal muscle quality has recently been acknowledged as a key determinant of the clinical outcomes of ASD. Although the Scoliosis Research Society-Schwab ASD classification system incorporates the radiological factors related to HRQoL, it cannot accurately predict the mechanical complications. With the rapid advances in surgical techniques, many surgical options for ASD have been developed, ranging from minimally invasive surgery to osteotomies. Therefore, structured patient-specific management is important in surgical decision-making, selecting the proper surgical technique, and to prevent serious complications in patients with ASD. Moreover, utilizing the latest technologies such as robotic-assisted surgery and machine learning, should help in minimizing the surgical risks and complications in the future.

Be Prepared: Preoperative Coronal Malalignment Often Leads to More Extensive Surgery Than Sagittal Malalignment During Adult Spinal Deformity Surgery

Scott L. Zuckerman,Christopher S. Lai,Yong Shen,Mena G. Kerolus,Alex S. Ha,Ian A. Buchanan,Nathan J. Lee,Eric Leung,Meghan Cerpa,Ronald A. Lehman,Lawrence G. Lenke 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Objective: To evaluate the effect of coronal alignment on: (1) surgical invasiveness and operative complexity and (2) postoperative complications. Methods: A retrospective, cohort study of adult spinal deformity patients was conducted. Alignment groups were: (1) neutral alignment (NA): coronal vertical axis (CVA)≤3 cm and sagittal vertical axis (SVA)≤5 cm; (2) coronal malalignment (CM) only: CVA>3 cm; (3) Sagittal malalignment (SM) only: SVA>5 cm; and (4) coronal and sagittal malalignment (CCSM): CVA>3 cm and SVA>5 cm. Results: Of 243 patients, alignment groups were: NA 115 (47.3%), CM 48 (19.8%), SM 38 (15.6%), and CCSM 42 (17.3%). Total instrumented levels (TILs) were highest in CM (14.5±3.7) and CCSM groups (14±4.0) (p<0.001). More 3-column osteotomies (3COs) were performed in SM (21.1%) and CCSM (28.9%) groups than CM (10.4%) (p=0.003). CM patients had more levels instrumented (p=0.029), posterior column osteotomies (PCOs) (p<0.001), and TLIFs (p=0.002) than SM patients. CCSM patients had more TLIFs (p=0.012) and higher estimated blood loss (EBL) (p=0.003) than SM patients. CVA displayed a stronger relationship with TIL (p=0.002), EBL (p<0.001), and operative time (p<0.001) than SVA, which had only one significant association with EBL (p=0.010). Both SM/CCSM patients had higher readmissions (p=0.003) and reoperations (p<0.001) than CM patients. Conclusion: Amount of preoperative CM was a better predictor of surgical invasiveness than the amount of SM, despite 3COs more commonly performed in SM patients. CM patients had more instrumented levels, PCOs, and TLIFs than SM patients.

Neurologic Deficit During HaloGravity Traction in the Treatment of Severe Thoracic Kyphoscoliotic Spinal Deformity

Martin H. Pham,Meghan Cerpa,Melvin C. Makhni,John Alexander Sielatycki,Lawrence G. Lenke 대한척추신경외과학회 2020 Neurospine Vol.17 No.2

Correction of severe spinal deformity is a significant challenge for spinal surgeons. Although halo-gravity traction (HGT) has been shown to be well-tolerated and safe, we report here a case of neurologic decline during treatment. A 24-year-old male presents with severe thoracic kyphoscoliosis with > 180° of 3-dimensional deformity. Magnetic resonance imaging showed his thoracic spinal cord draped across his T7–9 apex. His neurologic exam showed lower extremity myelopathy. During week 7 at a goal traction weight of 18.1 kg, his distal lower extremity exam declined from 4+/5 to 2/5. His traction weight was lowered to 11.3 kg. He subsequently sustained a ground-level fall and became paraparetic with a motor exam of 1–2/5. He subsequently underwent a T1–L4 posterior spinal instrumentation and fusion with a T7–9 vertebral column resection. Postoperatively, he was noted to have a complete return to his baseline neurologic exam. At his 4-month postoperative visit, he was now full strength in his lower extremities with complete resolution of his myelopathy. We present here a case of neurologic decline in a patient with severe kyphoscoliosis who underwent HGT and discuss the management decisions associated with this challenging scenario.

Outcomes of Non-Operative Management for Pseudarthrosis after Pedicle Subtraction Osteotomies at Minimum 5 Years Follow-Up

Kim, Yong-Chan,Kim, Ki-Tack,Kim, Cheung-Kue,Hwang, Il-Yeong,Jin, Woo-Young,Lenke, Lawrence G.,Cha, Jae-Ryong The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.5

Objective : Minimal data exist regarding non-operative management of suspected pseudarthrosis after pedicle subtraction osteotomy (PSO). This study reports radiographic and clinical outcomes of non-operative management for post-PSO pseudarthrosis at a minimum 5 years post-detection. Methods : Nineteen consecutive patients with implant breakage indicating probable pseudarthrosis after PSO surgery (13 women/six men; mean age at surgery, 58 years) without severe pain and disability were treated with non-operative management (mean follow-up, 5.8 years; range, 5-10 years). Non-operative management included medication, intermittent brace wearing and avoidance of excessive back strain. Radiographic and clinical outcomes analysis was performed. Results : Sagittal vertical axis (SVA), proximal junctional angle, thoracic kyphosis achieved by a PSO were maintained after detection of pseudarthrosis through ultimate follow-up. Lumbar lordosis and PSO angle decreased at final follow-up. There was no significant change in Oswestry Disability Index (ODI) scores and Scoliosis Research Society (SRS) total score, or subscales of pain, self-image, function, satisfaction and mental health between detection of pseudarthrosis and ultimate follow-up. SVA greater than 11 cm showed poorer ODI and SRS total score, as well as the pain, self-image, and function subscales (p<0.05). Conclusion : Non-operative management of implant failure of probable pseudarthrosis after PSO offers acceptable outcomes even at 5 years after detection of implant breakage, provided SVA is maintained. As SVA increased, outcome scores decreased in this patient population.