Commentary on “Modified Global Alignment and Proportion Scoring With Body Mass Index and Bone Mineral Density Analysis in Global Alignment and Proportion Score of Each 3 Categories for Predicting Mechanical Complications After Adult Spinal Deformity Sur

Dean Chou 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

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How Should We Consider New Theories of Chiari Malformation Pathogenesis?

Dean Chou 대한척추신경외과학회 2019 Neurospine Vol.16 No.2

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The Navigated Oblique Lumbar Interbody Fusion: Accuracy Rate, Effect on Surgical Time, and Complications

Zhuo Xi,Dean Chou,Praveen V. Mummaneni,Shane Burch 대한척추신경외과학회 2020 Neurospine Vol.17 No.1

Objective: The oblique lumbar interbody fusion (OLIF) can be done with either fluoroscopy or navigation. However, it is unclear how navigation affects the overall flow of the procedure. We wished to report on the accuracy of this technique using navigation and on how navigation affects surgical time and complications. Methods: A retrospective review was undertaken to evaluate patients who underwent OLIF using spinal navigation at University of California San Francisco. Data collected were demographic variables, perioperative variables, and radiographic images. Postoperative lateral radiographs were analyzed for accuracy of cage placement. The disc space was divided into 4 quadrants from anterior to posterior, zone 1 being anterior, and zone 4 being posterior. The accuracy of cage placement was assessed by placement. Results: There were 214 patients who met the inclusion criteria. A total of 350 levels were instrumented from L1 to L5 using navigation. The mean follow-up time was 17.42 months. The mean surgical time was 211 minutes, and the average surgical time per level was 129.01 minutes. After radiographic analysis, 94.86% of cages were placed within quartiles 1 to 3. One patient (0.47%) underwent revision surgery because of suboptimal cage placement. For approach-related complications, transient neurological symptoms were 10.28%, there was no vascular injury. Conclusion: The use of navigation to perform OLIF from L1 to L5 resulted in a cage placement accuracy rate of 94.86% in 214 patients.

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

Choi, Seung Won,Ames, Christopher,Berven, Sigurd,Chou, Dean,Tay, Bobby,Deviren, Vedat The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.6

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 $36.4^{\circ}$ preoperatively up to $48.9^{\circ}$ (71.4% of total correction) after LIF and $53.9^{\circ}$ after PSF. Lumbar coronal Cobb was prominently improved from $38.6^{\circ}$ preoperatively to $24.1^{\circ}$ (55.8% of total correction) after LIF, $12.6^{\circ}$ after PSF respectively. The mean pelvic incidence-lumbar lordosis mismatch was markedly improved from $22.2^{\circ}$ preoperatively to $8.1^{\circ}$ (86.5% of total correction) after LIF, $5.9^{\circ}$ 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.

Preoperative Narcotic Use, Impaired Ambulation Status, and Increased Intraoperative Blood Loss Are Independent Risk Factors for Complications Following Posterior Cervical Laminectomy and Fusion Surgery

Ryan K. Badiee,Andrew K. Chan,Joshua Rivera,Annette Molinaro,Brianna R. Doherty,K. Daniel Riew,Dean Chou,Praveen V. Mummaneni,Lee A. Tan 대한척추신경외과학회 2019 Neurospine Vol.16 No.3

Objective: This retrospective cohort study seeks to identify risk factors associated with complications following posterior cervical laminectomy and fusion (PCLF) surgery. Methods: Adults undergoing PCLF from 2012 through 2018 at a single center were identified. Demographic and radiographic data, surgical characteristics, and complication rates were compared. Multivariate logistic regression models identified independent predictors of complications following surgery. Results: A total of 196 patients met the inclusion criteria and were included in the study. The medical, surgical, and overall complication rates were 10.2%, 23.0%, and 29.1% respectively. Risk factors associated with medical complications in multivariate analysis included impaired ambulation status (odds ratio [OR], 2.27; p=0.02) and estimated blood loss over 500 mL (OR, 3.67; p=0.02). Multivariate analysis revealed preoperative narcotic use (OR, 2.43; p=0.02) and operative time (OR, 1.005; p=0.03) as risk factors for surgical complication, whereas antidepressant use was a protective factor (OR, 0.21; p=0.01). Overall complication was associated with preoperative narcotic use (OR, 1.97; p=0.04) and higher intraoperative blood loss (OR, 1.0007; p=0.03). Conclusion: Preoperative narcotic use and estimated blood loss predicted the incidence of complications following PCLF for CSM. Ambulation status was a significant predictor of the development of a medical complication specifically. These results may help surgeons in counseling patients who may be at increased risk of complication following surgery.

Utility of the MISDEF2 Algorithm and Extent of Fusion in Open Adult Spinal Deformity Surgery With Minimum 2-Year Follow-up

Bo Li,Gregory Hawryluk,Praveen V. Mummaneni,Michael Wang,Ratnesh Mehra,Minghao Wang,Darryl Lau,Rory Mayer,Kai-Ming Fu,Dean Chou 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

Objective: Long-segment fusion in adult spinal deformity (ASD) is often needed, but more focal surgeries may provide significant relief with less morbidity. The minimally invasive spinal deformity surgery (MISDEF2) algorithm guides minimally invasive ASD surgery, but it may be useful in open ASD surgery. We classified ASD patients undergoing focal decompression, limited decompression and fusion, and full correction according to MISDEF2 and correlated outcomes. Methods: A retrospective study of ASD patients treated by 2 surgeons at our hospital was performed. Inclusion criteria were: age >50, minimum 2-year follow-up, and open ASD surgery. Tumor, trauma, and infections were excluded. Patients had open surgery including focal decompression, short segment fusion, or full scoliosis correction. All patients were categorized by MISDEF2 into 4 classes based upon spinopelvic parameters. Perioperative metrics were assessed. Radiographic correction, complications and reoperation were recorded. Results: A total of 136 patients met inclusion criteria. Mean follow-up was 46±15.8 months (range, 24–118 months). Forty-seven underwent full deformity correction, 71 underwent short segment fusion, and 18 underwent decompression alone. There were 24 cases of class I, 66 cases of class II, 23 cases of class III, and 23 cases of class IV patients. Patients in class I and II had perioperative complication rates of 0% and 16.7% and revision rates of 8% and 21.2% when undergoing focal decompression or limited fusion. However, class II patients undergoing full correction had higher perioperative complications rate (p=0.03) and revision surgery rates (p=0.047). This difference was not seen in class III patients (p>0.05). All class IV patients underwent full correction, but they had higher perioperative complication rates (p<0.019), comparable revision surgery rates (p=0.27), and better radiographic realignment (p<0.001). In addition, full deformity correction was associated with longer length of stay, increased blood loss, and longer operative time (p<0.001). Conclusion: The MISDEF2 algorithm may help guide ASD surgical decision making even in open surgery, with focal treatment used in class I and II patients as a viable alternative and full correction implemented in class IV patients because of severe malalignment. However, class II patients with ASD undergoing full deformity correction do have higher complication rates.

Prioritization of Realignment Associated With Superior Clinical Outcomes for Cervical Deformity Patients

Katherine E. Pierce,Peter G. Passias,Avery E. Brown,Cole A. Bortz,Haddy Alas,Lara Passfall,Oscar Krol,Nicholas Kummer,Renaud Lafage,Dean Chou,Douglas C. Burton,Breton Line,Eric Klineberg,Robert Hart,J 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Objective: To prioritize the cervical parameter targets for alignment. Methods: Included: cervical deformity (CD) patients (C2–7 Cobb angle>10°, cervical lordosis>10°, cervical sagittal vertical axis [cSVA]>4 cm, or chin-brow vertical angle>25°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical [C] or cervicothoracic [CT] Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA (<4 cm) and T1 slope minus cervical lordosis (TS–CL) (<15°) were excluded. Patients assessed: meeting minimum clinically important differences (MCID) for NDI (<-15 ΔNDI). Ratios of correction were found for regional parameters categorized by primary Ames driver (C or CT). Decision tree analysis assessed cutoffs for differences associated with meeting NDI MCID at 1Y. Results: Seventy-seven CD patients (mean age, 62.1 years; 64% female; body mass index, 28.8 kg/m2). Forty-one point six percent of patients met MCID for NDI. A backwards linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R2 of 0.820 (p=0.032) included TS–CL, cSVA, McGregor’s slope (MGS), C2 sacral slope, C2–T3 angle, C2–T3 SVA, cervical lordosis. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the 2 groups (p> 0.050). Decision tree analysis determined cutoffs for radiographic change, prioritizing in the following order: ≥42.5° C2–T3 angle, >35.4° cervical lordosis, <-31.76° C2 slope, <-11.57-mm cSVA, <-2.16° MGS, >-30.8-mm C2–T3 SVA, and ≤-33.6° TS–CL. Conclusion: Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.